Diagnostic Aids

NOTE: You should enter this Pinpoint Test only when directed here from Diagnostic Routines

To prevent the replacement of good components, be aware that the following non-EEC areas may be at fault:

Fuel system
Fuel Contamination
A/C system
Starting/charging system

This Pinpoint Test is intended to diagnose only the following:

Constant Control Relay Module (CCRM)
- EEC Power Relay
- FC/LFC Relay
- HFC Relay
- WAC Relay
- FP Relay
Pusher Fan Control Relay
Harness circuits: B+, KPWR, PWR GND, FP, LFP, HFP, FC, LFC, HFC, PFC, A/C, ACCS, ACPSW, WAC
Powertrain Control Module (PCM) (12A650)

Constant Control Relay Module (CCRM)

The Constant Control Relay Module (CCRM) interfaces with the EEC-IV system to provide control for the cooling fan, A/C clutch and the fuel pump. The CCRM also contains the EEC power relay which provides vehicle battery power (VPWR) to the Powertrain Control Module (PCM) and EEC-IV system. Refer to the following schematics for specific CCRM relay control.

Pusher Fan (Thunderbird SC)

The Thunderbird SC has a pusher fan for additional cooling. The pusher fan is located in front of the radiator and uses a stand-alone relay that is controlled by the PCM

Dual and Single Function A/C Pressure Switch (ACPSW) (also known as Refrigerant Containment Switch)

The ACPSW is used on some applications for additional A/C system pressure control and is also known as the refrigerant containment switch. The normally open medium pressure contacts close at a predetermined A/C head pressure and are used on all CCRM applications except the 2.3L Tempo/Topaz. This grounds the input to the PCM indicating that the high speed cooling fan is required. For the 3.0L SHO and Taurus Flex Fuel, the medium pressure ACPSW circuit is not wired to the PCM, but is wired directly to the CCRM for high speed cooling fan control. The normally closed high pressure contracts are used on all CCRM applications and open at a predetermined A/C head pressure. This turns off the A/C by opening the A/C demand circuit preventing the A/C pressure from rising to a level that would open the A/C high pressure relief valve. For additional information, refer to the Ventilation/Climate Control group of the service information.

Fig 1: A/C Pressure Switch

Courtesy of FORD MOTOR CO.

Fig 2: Pinpoint Test X Schematics (2.3L Tempo/Topaz)

Courtesy of FORD MOTOR CO.

Fig 3: CCRM Harness Connector (2.3L Tempo/Topaz)

Courtesy of FORD MOTOR CO.

Fig 4: Pinpoint Test X Schematics (3.0L Tempo/Topaz)

Courtesy of FORD MOTOR CO.

Fig 5: CCRM Harness Connector (3.0L Tempo/Topaz)

Courtesy of FORD MOTOR CO.

Fig 6: Pinpoint Test X Schematics (3.2L Taurus SHO)

Courtesy of FORD MOTOR CO.

Fig 7: CCRM Harness Connector (3.2L Taurus SHO)

Courtesy of FORD MOTOR CO.

Fig 8: Pinpoint Test X Schematics (3.0L Taurus SHO)

Courtesy of FORD MOTOR CO.

Fig 9: CCRM Harness Connector (3.0L Taurus SHO)

Courtesy of FORD MOTOR CO.

Fig 10: Pinpoint Test X Schematics (3.0L Taurus Flexible Fuel (FF))

Courtesy of FORD MOTOR CO.

Fig 11: CCRM Harness Connector (3.0L Taurus Flexible Fuel (FF))

Courtesy of FORD MOTOR CO.

Fig 12: Pinpoint Test X Schematics (3.0L Taurus/Sable (Except SHO and Flexible Fuel) 3.8L Taurus/Sable, Continental)

Courtesy of FORD MOTOR CO.

Fig 13: CCRM Harness Connector (3.0L Taurus/Sable (Except SHO and Flexible Fuel) 3.8L Taurus/Sable, Continental)

Courtesy of FORD MOTOR CO.

Fig 14: Pinpoint Test X Schematics (3.0L Taurus/Sable (Mustang, Thunderbird/Cougar (Except Thunderbird SC))

Courtesy of FORD MOTOR CO.

Fig 15: CCRM Harness Connector (3.0L Taurus/Sable (Mustang, Thunderbird/Cougar (Except Thunderbird SC))

Courtesy of FORD MOTOR CO.

Fig 16: Pinpoint Test X Schematics (Thunderbird SC)

Courtesy of FORD MOTOR CO.

Fig 17: CCRM Harness Connector (Thunderbird SC)

Courtesy of FORD MOTOR CO.

X1 CHECK BATTERY VOLTAGE

Key on, engine off.
Measure voltage across battery terminals

Is voltage greater than 10.5 volts?

Yes	No
GO to X2	SERVICE discharged battery, REFER to Charging/Electrical Group in Service Information

X2 CHECK BATTERY GROUND

Key on, engine off
Measure voltage between SIG RTN circuit in the Data Link Connector and battery negative post

Is voltage greater than 0.5 volt?

Yes	No
GO to X3	GO to X6

X3 GROUND FAULT ISOLATION

Key off
Disconnect Powertrain Control Module (PCM). Inspect for damaged or pushed out pins, corrosion, loose wires etc. Service as necessary
Install breakout box and connect PCM to breakout box
Key on, engine off.
Measure voltage between battery negative post and Test Pins 40 and 60 at the breakout box.

Is each voltage less than 0.5 volt?

Yes	No
GO to X4	SERVICE open ground circuit. REMOVE breakout box. RECONNECT PCM. RERUN Quick Test

X4 POWERTRAIN CONTROL MODULE (PCM) GROUND FAULT ISOLATION

Key off
Breakout box installed, PCM connected
Measure resistance between Test Pin 46 and Test Pins 40 and 60 at the breakout box

Is each resistance less than 5.0 ohms?

Yes	No
GO to X5	REPLACE PCM. REMOVE breakout box. RERUN Quick Test.

X5 CHECK SIG RTN CIRCUIT CONTINUITY

Key off
Breakout box installed, PCM disconnected
Measure resistance between Test Pin 46 at the breakout box and SIG RTN circuit in the Data Link Connector

Is resistance less than 5.0 ohms?

Yes	No
System OK. REMOVE breakout box. RECONNECT PCM. RERUN Quick Test.	SERVICE open circuit. REMOVE breakout box. RECONNECT PCM. RERUN Quick Test

X6 MEASURE VOLTAGE AND GROUND TO CCRM

Key off
Disconnect CCRM
Measure voltage between Pin 8 and Pin 15 at the CCRM vehicle harness connector
For Mustang and Thunderbird/Cougar also measure voltage between Pin 10 and Pin 15 at the CCRM vehicle harness connector

Is voltage greater than 10.5 volts?

Yes	No
GO to X7	GO to X9

X7 CHECK KEY POWER TO CCRM

Key on, engine off
CCRM disconnected
Measure voltage between Pin 13 and Pin 15 at the CCRM vehicle harness connector

Is voltage greater than 10.5 volts?

Yes	No
GO to X8	SERVICE open between Pin 13 and ignition switch. RECONNECT CCRM. RERUN Quick Test

X8 CHECK VPWR CIRCUIT CONTINUITY

Key off
CCRM disconnected
Disconnect Powertrain Control Module (PCM). Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary
Install breakout box, leave PCM disconnected
Measure resistance between Test Pins 37 and 57 at the breakout box and Pin 24 at the CCRM vehicle harness connector
For Mustang and Thunderbird/Cougar, also measure resistance between Test Pins 37 and 57 at the breakout box and Pin 12 at the CCRM vehicle harness connector

Is each resistance less than 5.0 ohms?

Yes	No
REPLACE CCRM. REMOVE breakout box. RECONNECT all components. RERUN Quick Test	SERVICE open in VPWR circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test

X9 MEASURE CONTINUITY OF POWER GROUND TO CCRM

Key off
CCRM disconnected
Measure resistance between battery negative post and Pin 15 at the CCRM vehicle harness connector

Is resistance less than 5.0 ohms?

Yes	No
SERVICE open in battery positive to CCRM Pin 8/Pin 10. RECONNECT CCRM. RERUN Quick Test	SERVICE open in battery ground to CCRM Pin 15. RECONNECT CCRM. RERUN Quick Test

X10 DIAGNOSTIC TROUBLE CODE (DTC) 562: CHECK FOR VPWR TO PUSHER FAN CONTROL (PFC) RELAY

DTC 562 indicates a Pusher Fan Control (PFC) primary circuit failure

Possible causes:

Open or shorted circuit
Damaged PFC relay
Damaged Powertrain Control Module (PCM)

Key off
Disconnect PFC relay
Key on
Measure voltage between the VPWR pin at the PFC relay vehicle harness connector and the battery negative post
Key off

Was voltage greater than 10.5 volts?

Fig 18: PFC Relay Vehicle Harness Connector

Courtesy of FORD MOTOR CO.

Yes	No
GO to X11	SERVICE open in VPWR circuit to PFC relay. RECONNECT PFC relay. RERUN Quick Test

X11 CHECK PFC RELAY

Key off
PFC relay disconnected
DVOM on 200 ohm scale.
Check PFC relay coil by measuring resistance between Pins 85 and 86 of the PFC relay (pin numbers moulded on relay). Resistance should be between 40 and 85 ohms
DVOM on 10, 00 ohms scale
Check PFC relay for internal shorts by measuring resistance between Pin 85 and Pins 30 and 87 of the PFC relay. Both resistances should be greater than 10, 00 ohms

Are all resistance checks OK?

Fig 19: PFC Relay Connector Pins

Courtesy of FORD MOTOR CO.

Yes	No
GO to X12	REPLACE PFC relay. RERUN Quick Test

X12 CHECK PFC CIRCUIT FOR SHORT TO POWER

Key off
PFC relay disconnected
Disconnect Powertrain Control Module (PCM). Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary
Install breakout box, leave PCM disconnected
Key on, engine off
Measure voltage between Test Pin 34 and Test Pin 40 (GND) at the breakout box
Key off

Was voltage less than 1.0 volt?

Yes	No
GO to X13	SERVICE short circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test. If DTC 562 is still present, REPLACE PCM.

X13 CHECK PFC CIRCUIT FOR SHORT TO GROUND

Key off
PFC relay disconnected
Breakout box installed, PCM disconnected
Measure resistance between Test Pin 34 and Test Pin 40 at the breakout box

Is resistance greater than 10, 00 ohms?

Yes	No
GO to X14	SERVICE short circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test

X14 CHECK PFC CIRCUIT CONTINUITY

Key off
PFC relay disconnected
Breakout box installed, PCM disconnected
Measure resistance between the PFC circuit at the PFC relay vehicle harness connector and Test Pin 34 at the breakout box

Is resistance less than 5.0 ohms?

Yes	No
REPLACE PCM. RECONNECT PFC relay. RERUN Quick Test	SERVICE open circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test

X15 DIAGNOSTIC TROUBLE CODE (DTC) 563: CHECK HIGH FAN CONTROL (HFC) CIRCUIT IN CCRM

DTC 563 indicates a High Fan Control (HFC) primary circuit failure

Possible causes are:

Open or shorted circuit
Damaged CCRM
Damaged Powertrain Control Module (PCM).
ACPSW medium pressure contacts closed (3.0L Flex Fuel Taurus only).

Key off
Disconnect CCRM
Check HFC relay resistance in CCRM:
- Measure resistance between Pin 17 and Pin 24 (Pin 13 for Thunderbird SC) at the CCRM.
- Resistance should be between 50 and 100 ohms.
Check HFC circuit for shorts in CCRM:
- Measure resistance between Pin 17 and Pins 1 through 8 of the CCRM
- Also measure resistance between Pin 17 and the CCRM case
- All resistance should be greater than 10, 00 ohms

Are all checks OK?

Yes	No
For Thunderbird SC: GO to X16 All others: GO to X17	REPLACE CCRM. RERUN Quick Test

X16 CHECK VPWR CIRCUIT TO CCRM

Key off
CCRM disconnected
Disconnect EEC-IV power relay
Measure resistance between Pin 13 at the CCRM vehicle harness connector and the VPWR circuit at the EEC-IV power relay vehicle harness connector

Is resistance less than 5.0 ohms?

Fig 20: EEC-IV Power Relay Connector Pins

Courtesy of FORD MOTOR CO.

Yes	No
RECONNECT EEC-IV power relay. GO to X17	SERVICE open in VPWR circuit between EEC-IV power relay and CCRM. RECONNECT all components. RERUN Quick Test

X17 CHECK HFC CIRCUIT CONTINUITY

Key off
Disconnect Powertrain Control Module (PCM). Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary
Install breakout box, leave PCM disconnected
CCRM disconnected
Measure resistance between the HFC Test Pin at breakout box and Pin 17 of CCRM vehicle harness connector

Is resistance less than 5.0 ohms?

Application	HFC Test Pin
Thunderbird/Cougar	14
Mustang	32
All others	31

Yes	No
GO to X18	SERVICE open in HFC circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test

X18 CHECK HFC CIRCUIT FOR SHORT TO POWER

Key off
Breakout box installed, PCM disconnected
CCRM disconnected
Key on
Measure voltage between the HFC Test Pin at the breakout box and the battery negative post

Is voltage less than 1.0 volt?

Yes	No
Key off. GO to X19	SERVICE short to power. REMOVE breakout box. RECONNECT all components. RERUN Quick Test. If DTC 563 is still present, REPLACE PCM

X19 CHECK HFC CIRCUIT FOR SHORTS TO GROUND

Key off
Breakout box installed, PCM disconnected
CCRM disconnected
Measure resistance between the HFC Test Pin and Test Pin 40 at the breakout box

Is resistance greater than 10, 00 ohms?

Yes	No
REPLACE PCM. REMOVE breakout box. RECONNECT all components. RERUN Quick Test	For 3.0L Taurus Flex Fuel: GO to X155 All others: SERVICE short to ground in HFC circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test

X20 DIAGNOSTIC TROUBLE CODE (DTC) 564: DOES FAN RUN WITH KEY ON?

DTC 564 indicates a FC/LFC primary circuit failure

Possible causes are:

Open or shorted circuit
Damaged CCRM
Damaged PCM.

Does the cooling fan always run with the key on?

Yes	No
GO to X24	For Thunderbird SC: GO to X21 All others: GO to X22

X21 CHECK VPWR CIRCUIT TO CCRM

Key off
CCRM disconnected
Disconnect EEC-IV power relay
Measure resistance between Pin 13 at the CCRM vehicle harness connector and the VPWR circuit at the EEC-IV power relay vehicle harness connector

Is resistance less than 5.0 ohms?

Fig 21: EEC-IV Power Relay Vehicle Harness Connector

Courtesy of FORD MOTOR CO.

Yes	No
RECONNECT EEC-IV power relay. GO to X22	SERVICE open in VPWR circuit between EEC-IV power relay and CCRM. RECONNECT all components. RERUN Quick Test

X22 CHECK FC/LFC SIGNAL FOR SHORT TO GROUND

Key off
Disconnect Powertrain Control Module (PCM). Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary
Install breakout box, leave PCM disconnected
Disconnect CCRM

For 3.0L SHO and Mustang:

Measure resistance between Test Pin 55 and Test Pins 40/60 at the breakout box

For all others:

Measure resistance between Test Pin 13 and Test Pins 40/60 at the breakout box

Is resistance greater than 10, 00 ohms?

Yes	No
GO to X23	SERVICE short to ground in FC/LFC circuit. RECONNECT all components. RERUN Quick Test

X23 CHECK FAN RUNNING MODE

Key off
Breakout box installed, PCM disconnected
Connect CCRM
Key on, engine off

Does fan run?

Yes	No
REPLACE PCM. REMOVE breakout box. RECONNECT all components. RERUN Quick Test	REPLACE CCRM. REMOVE breakout box. RECONNECT all components. RERUN Quick Test

X24 CHECK FC/LFC CIRCUIT CONTINUITY

Key off
Disconnect Powertrain Control Module (PCM). Inspect for damaged or pushed out pins, corrosion, and loose wires, etc. Service as necessary
Install breakout box, leave PCM disconnected
Disconnect CCRM

For 3.0L SHO and Mustang:

Measure resistance between Test Pin 55 at the breakout box and Pin 14 at the CCRM vehicle harness connector

For all others:

Measure resistance between Test Pin 13 at the breakout box and Pin 14 at the CCRM vehicle harness connector

Is resistance less than 5.0 ohms?

Yes	No
GO to X25	SERVICE open in FC/LFC circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test

X25 CHECK FC/LFC CIRCUIT FOR SHORT TO POWER

Key off
Breakout box installed, PCM disconnected
CCRM disconnected
Key on, engine off

For 3.0L SHO and Mustang:

Measure voltage between Test Pin 55 at the breakout box and battery negative post.

For all others:

Measure voltage between Test Pin 13 at the breakout box and battery negative post.

Is voltage less than 1.0 volt?

Yes	No
GO to X26	SERVICE short to power in FC/LFC circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test

X26 FC/LFC CIRCUIT FAULT ISOLATION CHECK

Key off
Breakout box installed, PCM disconnected
Reconnect CCRM
Key on, engine off.

For 3.0L SHO and Mustang:

Jumper Test Pin 55 to Test Pin 40 or 60 at the breakout box

For all others:

Jumper Test Pin 13 to Test Pin 40 or 60 at the breakout box

Does fan continue to run?

Yes	No
Key off. REMOVE jumper. If DTC 563 was also present with the 564, GO to X150.If not, REPLACE CCRM. REMOVE breakout box. RECONNECT all components. RERUN Quick Test	REPLACE PCM. REMOVE breakout box and jumper. RECONNECT all components. RERUN Quick Test

X27 CHECK ACPSW MEDIUM PRESSURE CONTACT CIRCUIT TO CCRM FOR SHORT TO GND (3.0L SHO)

Key off
ACPSW disconnected
Disconnect CCRM
Measure resistance between Pin 17 at the CCRM vehicle harness connector and the battery negative post

Is resistance greater than 10, 00 ohms?

Yes	No
REPLACE CCRM. RECONNECT all components. RE-EVALUATE symptom	SERVICE short to ground. RECONNECT all components. RE-EVALUATE symptom

X28 COOLING FAN ALWAYS ON (ANY SPEED) (3.8L SC): CHECK IF PUSHER FAN IS ALWAYS ON

Accessories off (A/C, defroster, etc.)
Key on, engine off

Is the pusher fan always on? (The pusher fan is in front of the radiator.)

Yes	No
Key off, GO to X29	Key off, GO to X30

X29 CHECK PUSHER FAN CONTROL RELAY

Key off
Disconnect Pusher Fan Control (PFC) Relay
Key on, engine off

Is the pusher fan still on?

Yes	No
Key off. SERVICE short to power on Power-To-Pusher Fan circuit. RECONNECT PFC relay. RE-EVALUATE symptom	Key off. REPLACE PFC relay. RE-EVALUATE symptom

X30 COOLING FAN ALWAYS ON (ANY SPEED): DISCONNECT CCRM AND CHECK IF FAN IS ON

NOTE: For proper results of this Test Step, a "pass" Diagnostic Trouble Code (DTC) 111 must have been received during EEC-IV Self-Test

Accessories off (A/C, etc.)
Key on, verify "cooling fan always on" symptom
Key off
Disconnect CCRM
Key on, engine off

Is cooling fan still on?

Yes	No
Key off. For 2.3L Tempo/Topaz and 3.2L SHO: SERVICE short to power on power-to-fan circuit (between CCRM and cooling fan). RECONNECT CCRM. RE-EVALUATE symptom All others: GO to X31	For vehicles that use R134a A/C refrigerant (except 2.3L Tempo/Topaz and 3.0L Taurus Flex Fuel): GO to X32 All others: Key off. REPLACE CCRM. RE-EVALUATE symptom

X31 CHECK LOW SPEED POWER-TO-FAN CIRCUIT FOR SHORT TO POWER

Key off
CCRM disconnected
Disconnect cooling fan
Measure voltage between Pin 1 (Pin 6 for Thunderbird SC) of the CCRM vehicle harness connector and the battery negative post

Is voltage less than 1.0 volt?

Yes	No
SERVICE short to power in high speed power-to-fan circuit. RECONNECT all components. RE-EVALUATE symptom	SERVICE short to power in low speed power-to-fan circuit. RECONNECT all components. RE-EVALUATE symptom

X32 CHECK DUAL FUNCTION A/C PRESSURE SWITCH (ACPSW)

Key off
Reconnect CCRM
Disconnect dual funciton A/C Pressure Switch (ACPSW) (also known as Refrigerant Containment/Fan Function Switch).
Start engine

Is cooling fan on?

Yes	No
Key off For 3.0L SHO: GO to X27 All others: GO to X33	Key off. GO to Ventilation/Climate Control Group of the Service Information to check ACPSW operation

X33 CHECK PCM

Key off
ACPSW disconnected
Key on, engine off
Measure voltage between the ACPSW circuit at the ACPSW vehicle harness connector and the battery negative post
Key off

Was voltage greater than 4.0 volts?

Fig 22: A/C Pressure Switch Vehicle Harness Connector

Courtesy of FORD MOTOR CO.

Yes	No
REPLACE CCRM. RECONNECT all components. RE-EVALUATE symptom	GO to X34

X34 CHECK ACPSW CIRCUIT FOR SHORT TO GROUND

Key off
ACPSW disconnected
PCM disconnected
Measure resistance between the ACPSW circuit at the ACPSW vehicle harness connector and the battery negative post

Is resistance greater than 10, 00 ohms?

Yes	No
REPLACE PCM. RECONNECT all components. RE-EVALUATE SYMPTOM	SERVICE ACPSW circuit short to ground. RECONNECT all components. RE-EVALUATE symptom

X35 NO ENGINE COOLING FAN (LOW SPEED AND/OR HIGH SPEED): CHECK POWER SUPPLY TO CCRM

Key off
Disconnect CCRM
Connect negative probe of DVOM to battery negative post
For 3.2L SHO:
- Check for voltage on Pins 1, 2, 6, and 7 at the CCRM vehicle harness connector
For all others:
- Check for voltage on Pins 3 and 4 at the CCRM vehicle harness connector
- For Thunderbird SC, also check for voltage on Pins 8 and 10 at the CCRM vehicle harness connector

Is each voltage greater than 10.0 volts?

Yes	No
GO to X36	SERVICE open in battery power circuit. For Thunderbird SC, if B+ was open to only two pins (3/4 or 8/10), SERVICE open and GO to X141.RECONNECT CCRM. RE-EVALUATE symptom

X36 CHECK FAN MOTOR OPERATION

Key off
CCRM disconnected
For 3.0L SHO, 2.3L Tempo/Topaz and Thunderbird SC:
- Jumper Pin 1 to Pin 3 at the CCRM vehicle harness connector.
For all others:
- Jumper Pin 3 to Pin 6 at the CCRM vehicle harness connector

Does fan run?

Yes	No
For 3.0L SHO and 2.3L Tempo/Topaz: GO to X41 For all others: GO to X37	GO to X38

X37 CHECK FAN MOTOR OPERATION

Key off
CCRM disconnected
For Thunderbird SC:
- Jumper Pin 3 to Pin 6 at CCRM vehicle harness connector
All others:
- Jumper Pin 3 to Pin 2 at CCRM vehicle harness connector

Does fan run?

Yes	No
GO to X41	GO to X40

X38 MEASURE BATTERY VOLTAGE SUPPLY AT FAN-BYPASSING CCRM

Key off
Disconnect cooling fan
CCRM disconnected
For 3.0L SHO, 2.3L Tempo/Topaz and Thunderbird SC:
- Jumper Pin 1 to Pin 3 at the CCRM vehicle harness connector
For all others:
- Jumper Pin 3 to Pin 6 at the CCRM vehicle harness connector
Negative probe of DVOM connected to the ground pin of the cooling fan vehicle harness connector
Check for voltage to the cooling fan vehicle harness connector (for 3.0L SHO, check Power-To-Low Fan pin, for all other two-speed fan applications, check Power-To-High Fan pin).

Is voltage greater than 8.0 volts?

Yes	No
REPLACE fan motor. RECONNECT CCRM. RE-EVALUATE symptom	GO to X39

X39 VERIFY COOLING FAN GROUND

Key off
Cooling fan disconnected
CCRM disconnected
For 3.0L SHO, 2.3L Tempo/Topaz and Thunderbird SC:
- Jumper Pin 1 to Pin 3 at the CCRM vehicle harness connector
For all others:
- Jumper Pin 3 to Pin 6 at the CCRM vehicle harness connector
Connect negative probe of DVOM to the battery negative post
Check for voltage to the cooling fan vehicle harness connector (for 3.0L SHO, check Power-To-Low Fan pin, for all other two-speed fan applications, check Power-To-High Fan pin).

Is voltage greater than 8.0 volts?

Yes	No
SERVICE open in ground circuit to fan. RECONNECT all components. RE-EVALUATE symptom	For Thunderbird SC: GO to X140 All others: SERVICE open in power-to-fan circuit from CCRM vehicle harness connector to cooling fan vehicle harness connector. RECONNECT all components. RE-EVALUATE symptom

X40 MEASURE BATTERY VOLTAGE SUPPLY AT FAN-BYPASSING CCRM

Key off
Disconnect cooling fan
CCRM disconnected
For Thunderbird SC:
- Jumper Pin 3 to Pin 6 at CCRM vehicle harness connector
All others:
- Jumper Pin 3 to Pin 2 at CCRM vehicle harness connector
Measure voltage at cooling fan vehicle harness connector between power (HFC power for two speed fans) and ground pins

Is voltage greater than 8.0 volts?

Yes	No
REPLACE fan motor. RECONNECT CCRM. RE-EVALUATE symptom	SERVICE open in power-to-fan circuit from Pins 1 and 2 (6 and 7 for Thunderbird SC) of CCRM vehicle harness connector to cooling fan vehicle harness connector. RECONNECT all components. RE-EVALUATE symptom

X41 CHECK FAN RUNNING MODE (LOW)

Key off
Disconnect Powertrain Control Module (PCM).
Reconnect CCRM
Key on, engine off

Does fan run?

Yes	No
For 3.0L SHO and 2.3L Tempo/Topaz: GO to X44 For all others: GO to X42	REPLACE CCRM. RECONNECT PCM. RE-EVALUATE symptom

X42 JUMPER HIGH FAN CONTROL (HFC) SIGNAL TO GROUND

Key off
Inspect PCM for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary
Install breakout box, leave PCM disconnected
CCRM connected
Key on, engine off
For Mustang:
- Jumper Test Pin 32 to Test Pin 40 at the breakout box.
For Thunderbird/Cougar:
- Jumper Test Pin 14 to Test Pin 40 at the breakout box
All others:
- Jumper Test Pin 31 to Test Pin 40 at the breakout box

Does fan speed change from low to high?

Yes	No
GO to X44	For Thunderbird SC: GO to X43 All others: REPLACE CCRM. REMOVE breakout box. RECONNECT PCM. RE-EVALUATE symptom

X43 CHECK CONTINUITY OF HIGH SPEED POWER-TO-FAN CIRCUIT

Key off
Disconnect CCRM
Disconnect the 2 speed cooling fan
Measure resistance between Pin 1 and Pin 12 of the CCRM vehicle harness connector

Is resistance less than 5.0 ohms?

Yes	No
REPLACE CCRM. REMOVE breakout box. RECONNECT PCM. RE-EVALUATE symptom	SERVICE open circuit and REPLACE CCRM. REMOVE breakout box. RECONNECT all components. RE-EVALUATE symptom

X44 CHECK ECT SENSOR

Key off
Breakout box installed
Connect PCM to breakout box
Check engine coolant level
While measuring the voltage between Test Pin 7 and Test Pin 46, start engine and warm engine to operating temperature. Continue to let engine idle

Will the voltage drop below.5 volt? (Allow sufficient time for voltage to drop, being careful not to overheat engine. If cooling fan turns on, return to appropriate article for other possible causes of symptom.)

Yes	No
REPLACE PCM. REMOVE breakout box. RECONNECT all components. RE-EVALUATE symptom	CHECK ECT sensor wires and connector for high resistance. VERIFY cooling system is operating properly. If OK, REPLACE ECT sensor. REMOVE breakout box. RECONNECT all components. RE-EVALUATE symptom

X45 NO ENGINE COOLING FAN (ANY SPEED) (3.8L S/C): DOES THE PUSHER FAN OPERATE?

During the functional check of each cooling fan speed, did the Pusher Fan operate?

Yes	No
GO to X35	GO to X46

X46 CHECK B+ TO PUSHER FAN CONTROL RELAY

Key off
Disconnect Pusher Fan Control (PFC) relay
Measure voltage between the B+ circuit at the PFC relay vehicle harness connector and the battery negative post

Is voltage greater than 10.5 volts?

Fig 23: PFC Relay Vehicle Harness Connector

Courtesy of FORD MOTOR CO.

Yes	No
GO to X47	SERVICE open in B+ circuit. RECONNECT PFC relay. RE-EVALUATE symptom

X47 CHECK PUSHER FAN GROUND CIRCUIT

Key off
PFC relay disconnected
Disconnect pusher fan
Measure resistance between the ground circuit at the pusher fan vehicle harness connector and the battery negative post

Is resistance less than 5.0 ohms?

Yes	No
GO to X48	SERVICE open in ground circuit. RECONNECT all components. RE-EVALUATE symptom

X48 CHECK POWER-TO-PUSHER FAN CIRCUIT CONTINUITY

Key off
PFC relay disconnected
Pusher fan disconnected
Measure resistance between the Power-To-Pusher Fan circuit at the PFC relay vehicle harness connector and the Power-To-Pusher Fan circuit at the pusher fan vehicle harness connector

Is resistance less than 5.0 ohms?

Yes	No
GO to X49	SERVICE open in Power-To-Pusher Fan circuit. RECONNECT all components. RE-EVALUATE symptom

X49 CHECK OPERATION OF PFC RELAY

Key off
Reconnect PFC relay
Pusher fan disconnected
Again, enter Output State Diagnostic Test Mode (DTM)
Outputs off
Command the PFC output on by depressing the throttle (near WOT), waiting for the MIL to flash three consecutive times (about 20 seconds), then releasing the throttle
Measure voltage between the Power-To-Pusher Fan circuit at the pusher fan vehicle harness connector and the battery negative post

Is voltage greater than 10.5 volts?

Yes	No
EXIT Output State DTM. Key off. REPLACE pusher fan. RE-EVALUATE symptom	VERIFY test results. If voltage is still less than 10.5 volts, EXIT Output State DTM. Key off. REPLACE PFC relay. RECONNECT pusher fan. RE-EVALUATE symptom

X50 LOW/NO VOLTAGE TO A/C CLUTCH: CHECK FOR CONTINUITY FROM CCRM TO A/C CLUTCH

Key off
A/C clutch disconnected
Disconnect CCRM
Measure resistance between Pin 23 of the CCRM vehicle harness connector and power side of the A/C clutch vehicle harness connector
Measure resistance between Pin 16 of the CCRM vehicle harness connector and ground side of the A/C clutch vehicle harness connector

Is each resistance less than 5.0 ohms?

Yes	No
RECONNECT A/C clutch. GO to X51	SERVICE open in power or ground to A/C clutch. RECONNECT CCRM and A/C clutch. RE-EVALUATE symptom

X51 CHECK FOR A/C DEMAND SWITCH VOLTAGE TO CCRM

CCRM disconnected
Key on, engine off
A/C demand switch to A/C ON
Measure voltage between Pin 21 of the CCRM vehicle harness connector and battery negative post

Is voltage greater than 10.5 volts?

Yes	No
Key off. GO to X57	For vehicles that use R-12 A/C refrigerant: GO to X54 All others: GO to X52

X52 CHECK VOLTAGE TO A/C PRESSURE SWITCH (ACPSW)

Key off
Disconnect A/C Pressure Switch (ACPSW) (also known as Refrigerant Containment/Fan Function Switch).
Key on, engine off
A/C demand switch to A/C ON position
Measure voltage between the A/C Demand/Cyclic Pressure Switch Input pin at the ACPSW vehicle harness connector and the battery negative post
Key off

Was voltage greater than 10.5 volts?

Fig 24: A/C Pressure Switch Vehicle Harness Connector

Courtesy of FORD MOTOR CO.

Yes	No
GO to X53	GO to X54

X53 CHECK CONTINUITY BETWEEN ACPSW AND CCRM

Key off
ACPSW disconnected
CCRM disconnected
Measure resistance between the A/C demand to CCRM pin at the ACPSW vehicle harness connector and Pin 21 of the CCRM vehicle harness connector

Is resistance less than 5.0 ohms?

Yes	No
RECONNECT CCRM. GO to the Ventilation/Climate Control Group of the Service Manual to check the operation of the ACPSW. After any service, RECONNECT all other components and RE-EVALUATE symptom	SERVICE open circuit. RECONNECT all components. RE-EVALUATE symptom

X54 CHECK VOLTAGE TO CYCLIC PRESSURE SWITCH

Key off
Disconnect cyclic pressure switch
Key on, engine off
A/C demand switch to A/C ON position
Measure voltage between the A/C demand switch side of the cyclic pressure switch vehicle harness connector and battery negative post

Is voltage greater than 10.5 volts?

Yes	No
GO to X55	EEC-IV system OK. REMOVE breakout box. RECONNECT all components. REFER to Ventilation/Climate Control Group in the Service Manual for A/C diagnosis. (Inspect A/C Demand Switch, applicable fuses, wiring to cyclic pressure switch, etc.)

X55 CHECK CONTINUITY BETWEEN CYCLIC PRESSURE SWITCH AND CCRM OR ACPSW

Key off.
Cylic pressure switch disconnected
CCRM disconnected
ACPSW disconnected (if applicable).
For vehicles that use R-12 refrigerant:
- Measure resistance between the A/C demand circuit to CCRM pin at the cyclic pressure switch vehicle harness connector and Pin 21 of the CCRM vehicle harness connector
All others:
- Measure resistance between the A/C demand circuit to ACPSW at the cyclic pressure switch vehicle harness connector and the A/C demand/cyclic pressure switch input pin at the ACPSW vehicle harness connector.

Is resistance less than 5.0 ohms?

Yes	No
RECONNECT CCRM. GO to the Ventilation/Climate Control Group of the Service Manual to check the operation of the cyclic pressure switch. After any service, RECONNECT all components and RE-EVALUATE symptom	SERVICE open circuit. RECONNECT all components. RE-EVALUATE symptom

X57 CHECK FOR A/C DEMAND SWITCH VOLTAGE TO POWERTRAIN CONTROL MODULE (PCM)

Key off
Disconnect Powertrain Control Module (PCM). Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary
Install breakout box, leave PCM disconnected
CCRM disconnected
Key on, engine off
A/C demand switch to A/C ON
Measure voltage between Test Pin 10 and chassis ground

Is voltage greater than 10.5 volts?

Yes	No
Key off. GO to X58	Key off. SERVICE open in ACCS circuit between PCM and its connection to the A/C demand circuit. REMOVE breakout box. RECONNECT all components. RE-EVALUATE symptom

X58 CHECK WAC CIRCUIT FOR SHORTS TO GROUND

Key off
Breakout box installed, PCM disconnected
CCRM disconnected
Measure resistance between Test Pin 54 and chassis ground

Is resistance greater than 10, 00 ohms?

Yes	No
GO to X62	SERVICE short to ground in WAC circuit. REMOVE breakout box. RECONNECT all components. RE-EVALUATE symptom

X60 NO A/C CUTOFF: CHECK WAC CIRCUIT CONTINUITY

Key off
Disconnect Powertrain Control Module (PCM). Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary
Install breakout box, leave PCM disconnected
Disconnect CCRM
Measure resistance between Test Pin 54 at the breakout box and Pin 22 at the CCRM vehicle harness connector

Is resistance less than 5.0 ohms?

Yes	No
GO to X61	SERVICE open in WAC circuit. REMOVE breakout box. RECONNECT all components. RE-EVALUATE symptom

X61 CHECK WAC CIRCUIT FOR SHORTS TO POWER

Key off
Breakout box installed, PCM disconnected
CCRM disconnected
Key on, engine off
Measure voltage between Test Pin 54 and battery negative post

Is voltage less than 1.0 volt?

Yes	No
GO to X62	Key off. SERVICE short to power in WAC circuit. REMOVE breakout box. RECONNECT all components. RE-EVALUATE symptom

X62 ISOLATE FAULT TO PCM OR CCRM

Key off
Breakout box installed, PCM disconnected
Reconnect CCRM and A/C clutch
Key on, engine off
A/C demand switch to A/C on position
Connect jumper between Test Pins 54 and 40 at the breakout box
Disconnect and reconnect jumper several times while listening to the A/C clutch

Does the A/C clutch engage and disengage as the jumper is disconnected and reconnected?

Yes	No
For No A/C symptom: REMOVE jumper. GO to X63 For No WAC symptom: REPLACE PCM. REMOVE breakout box. RECONNECT all components. RE-EVALUATE symptom	REPLACE CCRM. INSPECT the A/C clutch circuit for possible shorts to GND. SERVICE as necessary. REMOVE breakout box. RECONNECT all components. RE-EVALUATE symptom

X63 CHECK ECT AND TP INPUTS

Key off
Breakout box installed
Reconnect PCM to breakout box
A/C on
Start engine
Check ECT input:
- Measure voltage between Test Pin 7 and Test Pin 40 at the breakout box
- ECT voltage should be greater than 0.3 volt
Check TP input:
- Measure voltage between Test Pin 47 and Test Pin 40 at the breakout box
- At closed and part throttle, the TP voltage should stay below 4.5 volts

Do the ECT and TP input voltages check out OK?

Yes	No
REPLACE PCM. REMOVE breakout box. RECONNECT all components. RE-EVALUATE symptom	PERFORM EEC-IV Quick Test. SERVICE any DTCs as directed. If OK, CHECK ECT/TP wiring for opens or shorts. SERVICE as necessary. REMOVE breakout box. RECONNECT all components. RE-EVALUATE symptom

X65 CHECK DUAL FUNCTION A/C PRESSURE SWITCH (ACPSW) INPUT

Key off
Unplug dual function A/C Pressure Switch (ACPSW) (also known as Refrigerant Containment/Fan Function Switch).
A/C off (to prevent chance of short circuit).
Start engine
Jumper ACPSW circuit to GND circuit at the ACPSW vehicle harness connector

Does the high speed fan come on?

Fig 25: A/C Pressure Switch Vehicle Harness Connector

Courtesy of FORD MOTOR CO.

Yes	No
Key off. ACPSW circuit is OK. REMOVE jumper. RECONNECT ACPSW. GO to the Ventilation/Climate Control Group of the Service Manual to check operation of the medium pressure function of the dual function A/C pressure switch. If OK, RETURN to appropriate article for other possible causes	GO to X66

X66 CHECK GND CIRCUIT TO ACPSW

Engine running
ACPSW disconnected
Connect jumper wire between ACPSW circuit at the ACPSW vehicle harness connector and the battery negative post

Does the high speed fan now come on?

Yes	No
Key off. SERVICE open GND circuit to ACPSW. RECONNECT ACPSW. RE-EVALUATE symptom	Key off. For 3.0L SHO and 3.0L Flex Fuel Taurus: GO to X68 All others: GO to X67

X67 CHECK ACPSW CIRCUIT CONTINUITY TO PCM

Key off
ACPSW disconnected
Disconnect Powertrain Control Module (PCM). Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary
Install breakout box, leave PCM disconnected
Measure resistance between Test Pin 42 at the breakout box and the ACPSW circuit at the ACPSW vehicle harness connector

Is resistance less than 5.0 ohms?

Yes	No
REPLACE PCM. REMOVE breakout box. RECONNECT all components. RE-EVALUATE symptom	SERVICE open circuit. REMOVE breakout box. RECONNECT all components. RE-EVALUATE symptom

X68 CHECK ACPSW CIRCUIT CONTINUITY TO CCRM

Key off
ACPSW disconnected
Disconnect CCRM
Measure resistance between Pin 17 of the CCRM vehicle harness connector and the ACPSW circuit at the ACPSW vehicle harness connector

Is resistance less than 5.0 ohms?

Yes	No
For 3.0L Flex Fuel Taurus: GO to X160 For 3.0L SHO: GO to X69	SERVICE open circuit. RECONNECT all components. RE-EVALUATE symptom

X69 CHECK HIGH SPEED FAN OPERATION, BYPASSING CCRM

Key off
ACPSW disconnected
CCRM disconnected
Jumper Pin 3 to Pin 6 at the CCRM vehicle harness connector

Does fan run?

Yes	No
REPLACE CCRM. RECONNECT all components. RE-EVALUATE symptom	CHECK continuity of Power-To-High Speed Fan circuit between CCRM and cooling fan. SERVICE as necessary. If OK, REPLACE cooling fan. RECONNECT all components. RE-EVALUATE symptom

X70 DIAGNOSTIC TROUBLE CODE (DTC) 556 OR 557: CHECK FUEL PUMP RELAY COIL RESISTANCE

DTC 556 for the 3.0L SHO indicates a high speed fuel pump primary circuit fault

DTC 556 for ALL OTHERS indicates a fuel pump primary circuit fault

DTC 557 indicates a low speed fuel pump primary circuit fault

Possible causes:

Open or shorted circuit
Open Inertia Fuel Shutoff (IFS) switch (Tempo/Topaz).
Damaged CCRM
Damaged Powertrain Control Module (PCM).

Key off
Disconnected CCRM
For Tempo/Topaz:
- Measure resistance of CCRM from Pin 18 to Pin 10.
- For Thunderbird SC:
- Measure resistance of CCRM from Pin 18 to Pin 13
- For all others:
- Measure resistance of CCRM from Pin 18 to Pin 24.

Is resistance between 65 and 120 ohms?

Yes	No
For Tempo/Topaz: GO to X71 For Thunderbird/Cougar: GO to X72 For all others: GO to X73	REPLACE CCRM. REMOVE breakout box. RECONNECT PCM. RERUN Quick Test

X71 CHECK VOLTAGE TO FUEL PUMP RELAY

CCRM disconnected
Key on
Measure voltage between CCRM Pin 10 at vehicle harness connector and battery negative post

Is voltage greater than 10.5 volts?

Yes	No
GO to X73	CHECK Inertia Fuel Shutoff switch for open or reset. If OK, SERVICE open in ignition START/RUN circuit to CCRM. RECONNECT CCRM. RERUN Quick Test

X72 CHECK VPWR CIRCUIT TO CCRM

Key off
CCRM disconnected
Disconnect EEC-IV power relay
Measure resistance between Pin 13 at the CCRM vehicle harness connector and the VPWR circuit at the EEC-IV power relay vehicle harness connector

Is resistance less than 5.0 ohms?

Fig 26: EEC-IV Power Relay Vehicle Harness Connector

Courtesy of FORD MOTOR CO.

Yes	No
RECONNECT EEC-IV power relay. GO to X73	SERVICE open in VPWR circuit between EEC-IV power relay and CCRM. RECONNECT all components. RERUN Quick Test

X73 CHECK CONTINUITY OF FUEL PUMP CIRCUIT

Key off
CCRM disconnected
Disconnect Powertrain Control Module (PCM). Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary
Install breakout box, leave PCM disconnected
Measure resistance between Test Pin 22 at the breakout box and Pin 18 at the CCRM vehicle harness connector
For 3.0L SHO, also measure resistance between Test Pin 41 at the breakout box and Pin 18 at the CCRM vehicle harness connector

Is resistance less than 5.0 ohms?

Yes	No
GO to X74	SERVICE open in fuel pump circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test

X74 CHECK FUEL PUMP CIRCUIT FOR SHORT TO POWER

Key off
Breakout box installed, PCM disconnected
CCRM disconnected
Key on
Measure voltage between Test Pin 22 and the battery negative post

Is voltage less than 1.0 volt?

Yes	No
GO to X75	SERVICE short to power. REMOVE breakout box. RECONNECT all components. RERUN Quick Test. If DTC 556/557 is still present, REPLACE PCM

X75 CHECK FUEL PUMP CIRCUIT FOR SHORT TO GROUND

Key off
Breakout box installed, PCM disconnected
CCRM disconnected
Measure resistance between Test Pin 22 and the battery negative post

Is resistance greater than 10, 00 ohms?

Yes	No
REPLACE PCM. REMOVE breakout box. RECONNECT all components. RERUN Quick Test	SERVICE fuel pump circuit short to ground. REMOVE breakout box. RECONNECT all components. RERUN Quick Test

X80 DIAGNOSTIC TROUBLE CODE (DTC) 542: DOES ENGINE START

Diagnostic Trouble Code (DTC) 542 indicates that one of the following has occurred:

No Start:

Inertia Fuel Shutoff (IFS) switch not reset or electrically open (if in secondary circuit)
Open circuit between the fuel pump and FPM circuit connection to power-to-pump circuit
Poor fuel pump ground
Fuel pump electrically open

Engine Starts:

Fuel pump secondary circuit short to power
Fuel pump relay contacts always closed
Open in FPM circuit between PCM and connection to power-to-pump circuit
Left/Front HO2S short to power (dual HO2S applications).
Damaged PCM

Does the engine start?

Yes	No
GO to X81	For Tempo/Topaz: REFER to the Fuel/Engine Group in the Service Manual (Electric Fuel Pump) for open in power-to-pump circuit, poor fuel pump ground, open in fuel pump, etc All others: GO to X85

X81 VERIFY THAT FUEL PUMP IS OFF

Key on, wait 5 seconds
Listen for motor noise from fuel pump (it may be necessary to listen by fuel tank).

Is fuel pump off?

Yes	No
GO to X84	For 3.0L Flex Fuel Taurus: GO to X82 All others: GO to X83

X82 CHECK FOR LOW SPEED FUEL PUMP (LFP) RELAY ALWAYS CLOSED

Key off
Disconnect LFP relay
Key on, wait 5 seconds

Does fuel pump shut off when LFP relay is disconnected?

Yes	No
REPLACE LFP relay. RERUN Quick Test	Key off. GO to X83

X83 CHECK FOR FUEL PUMP RELAY ALWAYS CLOSED

Key off
Disconnect CCRM
Key on

Does fuel pump shut off when CCRM is disconnected?

Yes	No
REPLACE CCRM. RERUN Quick Test	SERVICE short to power in power-to-pump/FPM circuit. RECONNECT CCRM. RERUN Quick Test

X84 CHECK FPM CIRCUIT CONTINUITY

Key off
Disconnect Powertrain Control Module (PCM). Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary
Install breakout box, leave PCM disconnected
Disconnect CCRM
Measure resistance between Test Pin 8 (Test Pin 19 for 3.0L SHO) at the breakout box and Pin 5 at the CCRM vehicle harness connector

Is resistance less than 5.0 ohms?

Yes	No
For dual HO2S applications: GO to X86 All others: REPLACE PCM. RECONNECT CCRM. RERUN Quick Test	SERVICE open circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test

X85 CHECK INERTIA FUEL SHUTOFF SWITCH

Key off
Locate and disconnect Inertia Fuel Shutoff (IFS) switch (verify that switch is reset).
Measure resistance between the "C" and "NC" pins of the IFS switch

Is resistance less than 5.0 ohms?

Yes	No
RECONNECT IFS switch. REFER to the Fuel/Engine Group in the Service Manual (Electric Fuel Pump) for open in power-to-pump circuit, poor fuel pump ground, open in fuel pump, etc	REPLACE or RESET IFS switch. RERUN Quick Test

X86 CHECK FRONT/LEFT HO2S FOR SHORT TO POWER

NOTE: Due to the internal circuitry of the PCM, a Left/Front HO2S signal short to power could produce a DTC 542/543.

Key off
Disconnect left or front HO2S
Measure resistance between HO2S signal pin and KEY POWER pin at the HO2S connector

Is resistance greater than 10, 00 ohms?

Fig 27: HO2S Connector Pins

Courtesy of FORD MOTOR CO.

Yes	No
GO to X87	REPLACE HO2S. REMOVE breakout box. RECONNECT all components. RERUN Quick Test

X87 CHECK HO2S CIRCUIT FOR SHORT TO POWER

Key off
Left or Front HO2S disconnected
Disconnect Powertrain Control Module (PCM). Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary. Leave PCM disconnected
Key on
Measure voltage between the HO2S signal at the HO2S vehicle harness connector and chassis ground

Is voltage less than 1.0 volt?

Fig 28: HO2S Connector Pins

Courtesy of FORD MOTOR CO.

Yes	No
REPLACE PCM. RECONNECT HO2S. RERUN Quick Test	SERVICE short circuit. RECONNECT PCM and HO2S. RERUN Quick Test.

X88 DIAGNOSTIC TROUBLE CODE (DTC) 524: CHECK B(+) TO LOW SPEED FUEL PUMP (LFP) RELAY

NOTE: If Key On Engine Off DTC 543 is also present, GO to X90

DTC 524 indicates a Low Speed Fuel Pump (LFP) secondary circuit failure

Possible causes (without DTC 543):

Open B(+) circuit to LFP relay
Open power-to-pump circuit between LFP relay and splice to "common" power-to-pump circuit
Damaged fuel pump dropping resistor
Damaged LFP relay

Key off
Disconnect LFP relay
Measure voltage between B(+) circuit at the LFP relay vehicle harness connector and the battery negative post

Is voltage greater than 10.5 volts?

Yes	No
GO to X89	VERIFY condition of related fuses. If OK, SERVICE open in B(+) circuit to LFP relay. RECONNECT LFP relay. RERUN Quick Test

X89 CHECK POWER-TO-PUMP CIRCUIT CONTINUITY BETWEEN LFP RELAY AND CCRM

Key off
LFP relay disconnected
Disconnect CCRM
Measure resistance between Pin 5 of the CCRM vehicle harness connector and the power-to-pump circuit at the LFP relay vehicle harness connector

Is resistance less than 10.0 ohms?

Fig 29: Checking Power-To-Pump Circuit Continuity

Courtesy of FORD MOTOR CO.

Yes	No
REPLACE LFP relay. RECONNECT all components. RERUN Quick Test	VERIFY condition of Fuel Pump Dropping Resistor (about 1 ohm resistance). If OK, SERVICE open in power-to-pump circuit between LFP relay and splice to "common" power-to-pump circuit. RECONNECT all components. RERUN Quick Test

X90 DIAGNOSTIC TROUBLE CODE (DTC) 543/524: DOES ENGINE START?

Diagnostic Trouble Code (DTC) 543/524 indicates a fuel pump secondary circuit failure between the B(+) supply and the FPM connection to the power-to-pump circuit

Possible causes:

No Starts:

Open circuit between the B(+) supply and the FPM connection to the power-to-pump circuit
Fuel pump relay contacts alway open

Engine Starts:

Left/Front HO2S short to power
Damaged Powertrain Control Module (PCM).

Does the engine start?

Yes	No
For 3.0L Flex Fuel Taurus: GO to X93 For all other dual HO2S applications: GO to X86 For single HO2S applications: REPLACE PCM. RERUN Quick Test	GO to X91

X91 CHECK B(+) SUPPLY TO FUEL PUMP RELAY

Key off
Disconnect CCRM
For Mustang and Thunderbird/Cougar:
- Measure voltage between Pin 11 at the CCRM vehicle harness connector and the battery negative post.
All others:
- Measure voltage between Pin 12 at the CCRM vehicle harness connector and battery negative post

Yes	No
GO to X92	VERIFY integrity of fuse/fuse link for B(+) supply to CCRM (fuel pump relay). If OK, SERVICE open in B(+) supply to CCRM. RECONNECT CCRM. RERUN Quick Test

X92 CHECK POWER-TO-PUMP CIRCUIT CONTINUITY

Key off
CCRM disconnected
Measure resistance between Pin 5 at the CCRM vehicle harness connector and the battery negative post

Is resistance less than 10.0 ohms?

Yes	No
REPLACE CCRM. RERUN Quick Test	SERVICE open in power-to-pump circuit between FPM splice and CCRM. RECONNECT CCRM. RERUN Quick Test

X93 CHECK B(+) SUPPLY TO HIGH SPEED FUEL PUMP RELAY

Key off
Disconnect CCRM
Measure voltage between Pin 12 at the CCRM vehicle harness connector and battery negative post

Is voltage greater than 10.5 volts?

Yes	No
GO to X94	SERVICE open in B(+) circuit between CCRM and B(+) splice to the High Speed and Low Speed Fuel Pump relays. RECONNECT CCRM. RERUN Quick Test

X94 CHECK POWER-TO-PUMP CONTINUITY BETWEEN CCRM AND IFS SWITCH

Key off
CCRM disconnected
Disconnect Inertia Fuel Shutoff (IFS) switch
Measure resistance between Pin 5 at the CCRM vehicle harness connector and the power-to-pump circuit from the CCRM circuit at the IFS switch vehicle harness connector

Is resistance less than 5.0 ohms?

Yes	No
GO to X95	SERVICE open in power-to-pump circuit between CCRM and splice to LFP relay. RECONNECT all components. RERUN Quick Test

X95 CHECK PCM ABILITY TO MONITOR FPM

Key off
Reconnect CCRM
Inertia Fuel Shutoff switch disconnected
Rerun Key On Engine Off Self-Test

Is KOEO DTC 542 present?

Yes	No
REPLACE CCRM. RECONNECT Inertia Fuel Shutoff switch. RERUN Quick Test	REPLACE PCM. RECONNECT Inertia Fuel Shutoff switch. RERUN Quick Test

X105 CONTINUOUS MEMORY DIAGNOSTIC TROUBLE CODE (DTC) 542: CHECK EEC-IV HARNESS

A Continuous Memory DTC 542 indicates that one of the following intermittent conditions has occurred:

Fuel pump circuit activated when PCM expected circuit to be off (i.e. fuel system test or prime procedure).
Inertia Fuel Shutoff switch was tripped, then reset (except Tempo/Topaz).
Open circuit in or between the fuel pump and FPM circuit at the PCM
Poor fuel pump ground
FPM or power-to-pump circuit short to power
Fuel pump relay contacts stuck closed
Left/Front HO2S circuit short to power (w/dual HO2S).
Engine stall due to excessive load.

Start engine
Check for engine stall/stumble while performing the following (also, if possible, listen for fuel pump turning off):
- Shake, wiggle, bend the Power-To-Pump circuit between the CCRM Pin 5 and the fuel pump
- Shake, wiggle, bend the fuel pump ground circuit from the fuel pump to ground
- Lightly tap the fuel pump to simulate road shock
- For all except Tempo/Topaz, lightly tap Inertia Fuel Shutoff switch to simulate road shock
- For 3.0L Flex Fuel (FF) Taurus, also shake, wiggle, bend the power-to-pump circuit to the Low Speed Fuel Pump (LFP) relay and lightly tap the LFP relay to simulate road shock
Key off
Inspect the fuel pump vehicle harness connector and the fuel pump ground for corrosion, damaged pins, etc

Is fault indicated/found?

Yes	No
ISOLATE fault and SERVICE as necessary. CLEAR Continuous Memory DTC. RERUN Quick Test	GO to X106

X106 CHECK FPM CIRCUIT

Key off
Disconnect PCM. Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary
Install breakout box, leave PCM disconnected
Key on, engine off
Connect a test lamp between Test Pin 8 (Test Pin 19 for 3.0L SHO) and Test Pin 37 at the breakout box
Observe test lamp for an indication of a fault while performing the following (the light will go out when a fault is found, indicating an open):
- Shake, wiggle, bend the Fuel Pump Monitor circuit between the splice into the power-to-pump circuit and the PCM

Is fault indicated?

Yes	No
ISOLATE fault and SERVICE as necessary. REMOVE breakout box. RECONNECT PCM. RERUN Quick Test	GO to X107

X107 CHECK FOR SHORTS TO POWER

Key on, engine off
Breakout box installed, PCM disconnected
Connect a test lamp between Test Pin 8 (Test Pin 19 for 3.0L SHO) and Test Pin 40
Observe test lamp for an indication of a fault while performing the following (The lamp will turn on when a fault is detected, indicating a short to power. Also, if possible, listen for fuel pump turning on.)
- Shake, wiggle, bend the Fuel Pump Monitor circuit and power-to-pump circuit, especially where they may be in the vicinity of a power circuit.
- For 3.0L FF Taurus, also shake, wiggle, bend the power-to-pump circuit to the LFP relay and lightly tap the LFP relay to simulate road shock
Lightly tap the CCRM (to simulate road shock).

Is fault indicated?

Yes	No
ISOLATE fault and SERVICE as necessary. REMOVE breakout box. RECONNECT PCM. RERUN Quick Test	For dual HO2S applications: GO to X116 All others: For further diagnosis using the EEC-IV monitor box or Scan Tool, GO to appropriate article. If an EEC-IV monitor box or Scan Tool is not available, GO to X120

X110 CONTINUOUS MEMORY DIAGNOSTIC TROUBLE CODE (DTC) 524/543: CHECK FOR CONTINUOUS MEMORY DTC 556/557

Is Continuous Memory DTC 556 or 557 also present?

Yes	No
GO to X115	GO to X111

X111 CHECK EEC-IV HARNESS

A Continuous Memory DTC 524/543, without the presence of a Continuous Memory DTC 556/557, indicates that during vehicle operation, one of the following has occurred (for the 3.0L Flex Fuel (FF) Taurus, DTC 524 refers to the low speed fuel pump circuit and DTC 543 refers to the high speed fuel pump circuit. Also, for the 3.0L FF Taurus, the Low Speed Fuel Pump (LFP) relay is external to the CCRM):

Open in the B(+) circuit between B(+) and the fuel pump relay
Fuel pump relay contacts opened
Open in the power-to-pump circuit from the CCRM/LFP relay to the FPM splice
Left/Front HO2S circuit short to power (w/dual HO2S).

Start engine
Check for engine stall/stumble while performing the following (also, if possible, listen for fuel pump turning off):
- Shake, wiggle, bend the fuel pump relay B(+) circuit to the CCRM/LFP relay
- Lightly tap the CCRM/LFP relay (to simulate road shock).
- Shake, wiggle, bend the power-to-pump circuit from the CCRM/LFP relay to the FPM splice
Key off.
Inspect the CCRM/LFP relay connector and B(+) connector terminal for corrosion, damaged pins, etc

Is fault indicated/found?

Yes	No
ISOLATE fault and SERVICE as necessary. CLEAR Continuous Memory DTC (REFER to Quick Test Appendix). RERUN Quick Test	Under certain conditions, a Continuous Memory DTC 524/543 may have been set without a Continuous Memory DTC 556/557, even though a fault has occurred in the fuel pump primary circuit. GO to X115 to check the fuel pump primary circuit.

X115 CONTINUOUS MEMORY DIAGNOSTIC TROUBLE CODE (DTC) 556/557: CHECK EEC-IV HARNESS

A Continuous Memory DTC 556/557 indicates a fuel pump primary circuit failure has occurred during vehicle operation (for the 3.0L SHO and 3.0L Flex Fuel Taurus. DTC 556 refers to the High Speed Fuel Pump primary circuit and DTC 557 refers to the Low Speed Fuel Pump primary circuit). Possible causes are:

Open VPWR in the CCRM
Open coil in fuel pump relay
Open in fuel pump circuit (PCM Pin 22 or 41).
Inertia Fuel Shutoff switch was tripped, then reset (Tempo/Topaz).
Open VPWR circuit to CCRM (Thunderbird SC).
Open VPWR to LFP relay (3.0L FF).

Start engine
Check for engine stall/stumble while performing the following (also, if possible, listen for fuel pump turning off):
- Shake, wiggle, bend the EEC-IV vehicle harness fuel pump circuit (Pin 22) between the PCM and the CCRM
- For Thunderbird SC, also shake, wiggle, bend the VPWR circuit between the EEC-IV power relay and the CCRM (Pin 13).
- Lightly tap the Inertia Fuel Shutoff (IFS) switch to simulate road shock (Tempo/Topaz).
- Lightly tap the CCRM to simulate road shock.
- For 3.0L FF Taurus with DTC 557, shake, wiggle, bend the VPWR circuit between the CCRM and LFP relay. Also lightly tap on the LFP relay to simulate road shock
Key off.
Inspect the PCM connector and the fuel pump relay connectors for corrosion, damaged pins, etc.

Is fault indicated/found?

Yes	No
ISOLATE fault and SERVICE as necessary. CLEAR Continuous Memory (REFER to Quick Test Appendix). RERUN Quick Test	For dual HO2S applications with a DTC 524/543 only: GO to X116 ALL others: For further diagnosis using the EEC-IV monitor box or Scan Tool, GO to appropriate article. If an EEC-IV monitor box or Scan Tool is not available, GO to X120

X116 CHECK LEFT/FRONT HO2S CIRCUIT FOR SHORT TO POWER

NOTE: Due to the internal circuitry of the PCM, an intermittent left/front HO2S signal short to power could produce a Continuous Memory DTC 542 or 524/543.

Key off
Install breakout box, if applicable
Breakout box installed, PCM disconnected
Connect a test lamp between the left/front HO2S test pin and test pin 40 at the breakout box (refer to Pinpoint Test H cover page for appropriate HO2S test pin).
Key on, engine off
Observe test lamp for an indication of a fault while performing the following (the light will turn on bright when a fault is detected):
- Shake, wiggle, bend the left/front HO2S circuit from the HO2S sensor to the PCM
- Lightly tap the HO2S sensor (to simulate road shock).

Is fault indicated?

Yes	No
ISOLATE fault and SERVICE as necessary. REMOVE breakout box. RECONNECT PCM. RERUN Quick Test	For further diagnosis using an EEC-IV monitor box or Scan Tool, GO to appropriate article. If an EEC-IV monitor box or Scan Tool is not available, GO to X120

X120 ROAD TEST

The purpose of the road test is to identify an area of concern by monitoring certain controlled parameters while trying to recreate a driveability or MIL symptom

NOTE: A basic working knowledge of the EEC-IV system is critical to effectively analyze road test data.

WARNING: THIS ROAD TEST IS A SUGGESTED BUT OPTIONAL PROCEDURE. ALL APPLICABLE SAFETY PROCEDURES AND TRAFFIC LAWS MUST BE FOLLOWED. IN ORDER FOR A ROAD TEST TO BE PERFORMED, IT IS REQUIRED THAT ANOTHER PERSON ACCOMPANY THE DRIVER. THE ACCOMPANYING PERSON CAN MAKE MEASUREMENTS, OBSERVE CHANGES AND RECORD NOTES. IF FOR SOME REASON THIS TEST IS NOT PERFORMED, RETURN TO APPROPRIATE ARTICLE FOR OTHER POSSIBLE CAUSES

Prepare Vehicle For A Road Test

Install breakout box, if applicable
Breakout box installed, PCM connected
Install fuel pressure gauge and MAP/BARO tester (optional).
Other materials needed; DVOM, pencil, paper, appropriate schematic/pin usage sheet
Preliminary Power/Ground Checks
With the key ON and a DVOM referenced to the battery negative post, check the following signals for correct values
POWERS: KAPWR > 10.5V (Pin 1), VPWR > 10.5V (Pins 37/57), VREF 5 ± 1V (Pin 26). GROUNDS: (all = 0 ±.V) PWR GND (Pins 40/60), SIG RTN (Pin 46), IGN GND (Pin 16). OPTIONAL GROUNDS: HO2S GND (Pin 49), CSE GND (Pin 20), MAF RTN (Pin 9 or 15)
Obtaining Other Information And Materials Before The Road Test
Refer to the Symptom Charts that most resemble the driveability or MIL symptom. Before the road test, perform the Visual/Mechanical Checks that are listed. Next, list the PCM sensors and actuators in the order given. These circuits and the FP/FPM signal(s) are the main signals that will be monitored
Refer to the proper Diagnostic Reference Value Sheet Appendix. Although these charts were designed for use with the EEC-IV monitor box, most of the values can be read using the breakout box and a DVOM (with the DVOM referenced to ground, all values in DCV units can be used; other values may also be helpful, ex., MAP Hz using the MAP/BARO tester).
The use of test lamp(s) and a DVOM may also aid diagnosis. Depending on the DTC being diagnosed, the FP/FPM circuits could be monitored, as well as the circuits to/from the Inertia Fuel Shutoff switch, the Left/Front HO2S circuit, etc. Remember, if the vehicle stalls, the PCM will "unground" the FP circuit and turn off the fuel pump. If the problem is in the fuel pump wiring, the lamp/voltage should change just BEFORE the symptom occurs
NOTE: Due to the low resistance of some test lamps, it is required that a DVOM or equivalent high resistance testing device be used when monitoring PCM output circuits.
Road Test
After starting the engine for the road test, enter Engine Running Continuous Monitor Diagnostic Test Mode
Drive the vehicle to create the conditions in which the symptom occurs. If the Customer Information Worksheet has been completed, this information may help in recreating the symptom
When the symptom occurs, the passenger should observe changes in listed PCM signals. Information about the symptom, operating condition, value of the PCM signal or other notes should be recorded
If the symptom cannot be duplicated, verify that the PCM values are in the expected range
Analyzing The Data
Once the road test is completed, the results should be analyzed to locate and service the fault which caused the symptom
If no problem is identified, return to appropriate article for other possible causes of the symptom

X130 DIAGNOSTIC TROUBLE CODE (DTC) 381: CHECK FOR CAUSES OF FAST A/C COMPRESSOR CLUTCH CYCLING

Continuous Memory DTC 381 indicates frequent A/C compressor clutch cycling.

To set DTC 381, the ACCS input to the Powertrain Control Module (PCM) (Pin 10) must change states in less than 8.5 seconds, and do so at least 10 times with few "good" (>8.5 seconds) cycle times in between.

Possible causes:

Mechanical A/C system concern (ex. low refrigerant charge, damaged cyclic pressure switch, etc.)
Intermittent open between the Electronic Automatic Temperature Control (EATC) module and the Pin 10 input (ACCS) to the PCM.

Refer to the Climate Control System articles of the Service Information to test A/C compressor clutch cycle times, and to check causes of fast clutch cycling.

Is a fault indicated?

Yes	No
SERVICE as required according to Service Information direction. CLEAR continuous memory. START engine and turn A/C on for about 2 minutes. Engine off, A/C off. RERUN Quick Test	GO to X131 (to check for intermittent electrical concern).

X131 CHECK FOR INTERMITTENT OPEN BETWEEN EATC MODULE AND PCM

Key off
Disconnect PCM. Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary
Install breakout box, leave PCM disconnected
Connect a non-powered test lamp between Test Pin 10 and Test Pin 40 at the breakout box
Key on
A/C on
Observe test lamp for an indication of a fault while performing the following (the light will turn off when a fault is detected, indicating an open):
- Shake, wiggle, bend the A/C demand/ACCS circuit between the EATC module and PCM. The drawing below shows the portion of circuit to be checked
- Lightly tap the cyclic pressure switch to simulate road shock
Disconnect and inspect the cyclic pressure switch connector and the EATC module connector

Is a fault indicated?

Fig 30: Checking For Intermittent Open Between EATC Module And PCM

Courtesy of FORD MOTOR CO.

Yes	No
ISOLATE fault and SERVICE as necessary. REMOVE breakout box. RECONNECT all components. CLEAR Continuous Memory. START engine and TURN A/C on for about 2 minutes. Engine off, A/C off. RERUN Quick Test.	UNABLE to duplicate fault at this time. REMOVE breakout box. RECONNECT all components. CLEAR Continuous Memory. Service any additional symptoms

X140 CHECK HARNESS CONTINUITY OF HIGH SPEED POWER TO FAN CIRCUITS

Key off
Cooling fan disconnected
CCRM disconnected
Measure resistance between Pin 1 and Pin 12 of the CCRM vehicle harness connector

Is resistance less than 5.0 ohms?

Yes	No
SERVICE open in high speed Power-To-Fan circuit between Pins 1/2/12/24 splice and the cooling fan. RECONNECT all components. RE-EVALUATE symptom	SERVICE open in high speed Power-To-Fan circuit between Pins 1/2/12/24 splice and CCRM. After service, GO to X141 to verify proper operation of both HFC relays in CCRM

X141 VERIFY OPERATION OF BOTH HFC RELAYS IN CCRM

Key off
CCRM disconnected
Connect a jumper wire between Pin 13 of the CCRM and the battery positive (+) post
Connect another jumper wire between Pin 17 of the CCRM and the battery negative (-) post
Measure resistance between Pin 10 and both Pins 12 and 24
Measure resistance between Pin 4 and both Pins 1 and 2

Are all resistances less than 5.0 ohms?

Yes	No
Both HFC relays are OK. REMOVE jumpers. After original service, RECONNECT all components. RE-EVALUATE symptom	REPLACE CCRM. After also performing orignal service, RECONNECT all components. RE-EVALUATE symptom

X150 CHECK HFC CIRCUIT FOR SHORT TO GROUND

Key off
Breakout box installed, PCM disconnected
Disconnect CCRM
Measure resistance between the HFC Test Pin and Test Pin 40 at the breakout box

Is resistance greater than 10, 00 ohms?

Yes	No
REPLACE CCRM. REMOVE breakout box. RECONNECT all components. RERUN Quick Test	SERVICE short to ground in HFC circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test

X155 CHECK DUAL FUNCTION A/C PRESSURE SWITCH (ACPSW) MEDIUM PRESSURE CONTACTS (3.0L FF TAURUS)

Key off
Breakout box installed, PCM disconnected
CCRM disconnected
Disconnect the dual function A/C Pressure Switch (ACPSW) (also known as the Refrigerant Containment/Fan Function Switch).
Again, measure resistance between Test Pin 31 and Test Pin 40 at the breakout box

Is resistance now greater than 10, 00 ohms?

Yes	No
GO to the Ventilation/Climate Control Group of the Service Information to check ACPSW operation	SERVICE short to ground in HFC circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test

X160 CHECK HFC RELAY PRIMARY CIRCUIT FOR OPEN IN CCRM (3.0L FF TAURUS)

Key off
ACPSW disconnected
CCRM disconnected
Measure resistance between Pin 17 and Pin 24 of the CCRM

Is resistance between 50 and 100 ohms?

Yes	No
No fault found. VERIFY test results. If all OK, RECONNECT all components. RETURN to appropriate article to continue diagnosis	REPLACE CCRM. RECONNECT all components. RE-EVALUATE symptom

X165 DIAGNOSTIC TROUBLE CODE (DTC) 557: CHECK FOR VPWR TO LOW SPEED FUEL PUMP (LFP) RELAY

DTC 557 indicates a low speed fuel pump primary circuit failure.

Possible causes:

Open or shorted circuit
Damaged LFP relay.
Damaged Powertrain Control Module (PCM).

Disconnect LFP relay
Key on, engine off
Measure voltage between the VPWR circuit at the LFP relay vehicle harness connector and the battery negative post.
Key off

Was voltage greater than 10.5 volts?

Fig 31: LFP Relay Vehicle Harness Connector

Courtesy of FORD MOTOR CO.

Yes	No
GO to X166	SERVICE open in VPWR circuit between CCRM and LFP relay. RERUN Quick Test

X166 CHECK LFP RELAY

Key off
LFP relay disconnected
DVOM on 200 ohm scale
Measure LFP relay coil resistance between the LFP pin and VPWR pin at the fuel pump relay. Resistance should be between 40 and 85 ohms
DVOM on 10, 00 ohm scale
Check LFP relay for internal shorts: Measure resistance between the LFP pin and both the power-to-pump and B(+) pins. Both resistances should be greater than 10, 00 ohms

Are all resistance checks OK?

Fig 32: Checking LFP Relay

Courtesy of FORD MOTOR CO.

Yes	No
GO to X167	REPLACE LFP relay. RERUN Quick Test

X167 CHECK LFP CIRCUIT FOR SHORT TO POWER

Key off
LFP relay disconnected
Disconnect PCM. Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary
Install breakout box, leave PCM disconnected
Key on, engine off
Measure voltage between Test Pin 32 at the breakout box and battery negative post

Is voltage less than 1.0 volt?

Yes	No
GO to X168	SERVICE short circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test

X168 CHECK LFP CIRCUIT FOR SHORT TO GROUND

Key off
Breakout box installed, PCM disconnected
LFP relay disconnected
Measure resistance between Test Pin 32 and Test Pins 40 and 60 at the breakout box

Is resistance greater than 10, 00 ohms?

Yes	No
GO to X169	SERVICE short circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test

X169 CHECK LFP CIRCUIT CONTINUITY

Key off
Breakout box installed, PCM disconnected
LFP relay disconnected
Measure resistance between the LFP circuit at the LFP relay vehicle harness connector and Test Pin 32 at the breakout box

Is resistance less than 5.0 ohms?

Yes	No
REPLACE PCM. RECONNECT LFP relay. RERUN Quick Test	SERVICE open circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test