Pinpoint Test T : P0A71, P0A74, P0A77

NOTE: The Inverter System Controller (ISC) is referred to as the SOBDMC (Secondary On-Board Diagnostic Control Module C) in the scan tool.

Normal Operation and Fault Conditions

REFER to: Electric Powertrain Control - System Operation and Component Description .

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
SOBDMC P0A71:00	Generator Phase U Current High: No Sub Type Information	This DTC sets when the U phase current is outside of the normal range.
SOBDMC P0A74:00	Generator Phase V Current High: No Sub Type Information	This DTC sets when the V phase current is outside of the normal range.
SOBDMC P0A77:00	Generator Phase W Current High: No Sub Type Information	This DTC sets when the W phase current is outside of the normal range.

Possible Sources

Wiring, terminals or connectors
Low voltage wiring
Other Inverter System Controller (ISC) DTCs
Inverter System Controller (ISC) calibration
Inverter System Controller (ISC) TRID block programming
Transmission

T1 READ THE INVERTER SYSTEM CONTROLLER (ISC) DIAGNOSTIC TROUBLE CODES (DTCS)
- Using a diagnostic scan tool, retrieve the Inverter System Controller (ISC) CMDTCs.
Are P0A71, P0A74 or P0A77 the only DTCs present?

Yes GO to T2

No DIAGNOSE all other Inverter System Controller (ISC) DTCs. REFER to Diagnostic Trouble Code (DTC) Chart .

T2 CHECK THE INVERTER SYSTEM CONTROLLER (ISC) CALIBRATION LEVEL
- Verify the Inverter System Controller (ISC) is at the latest calibration level.
Is the Inverter System Controller (ISC) at the latest calibration level?

Yes GO to T3

No UPDATE the Inverter System Controller (ISC) to the latest calibration level.

T3 VERIFY THE INVERTER SYSTEM CONTROLLER (ISC) TRID BLOCK HAS BEEN PROGRAMMED CORRECTLY

Verify the Inverter System Controller (ISC) TRID block has been programmed correctly. Refer to Module Reprogramming on the scan tool.

Has the TRID block been successfully programmed?

Yes

GO to T4

No	CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, reflash the Inverter System Controller (ISC) TRID block.

T4 VISUAL INSPECTION OF THE LOW VOLTAGE SYSTEM
- Ignition OFF.
- Depower the high voltage system. REFER to: High Voltage System De-energizing .
- Visually inspect all the low voltage cables.
- Make sure all the low voltage connectors are correctly and securely connected.
- Examine all the low voltage cables and connectors for damaged, burned or overheated insulation and loose or broken conditions.
Is a concern present?

Yes REPAIR as necessary. CLEAR the Inverter System Controller (ISC) DTCs and REPEAT the self-test.

No GO to T5

T5 CHECK THE GENERATOR RESOLVER CIRCUITS FOR AN OPEN

Ignition OFF.

De-energize the high voltage system. REFER to: High Voltage System De-energizing .

Disconnect HF45 Transmission C1111.

Disconnect Inverter System Controller (ISC) C199B.

Measure and record:

Positive Lead	Measurement / Action	Negative Lead
C199B-20	Courtesy of FORD MOTOR COMPANY	C1111-31
C199B-14	Courtesy of FORD MOTOR COMPANY	C1111-21
C199B-21	Courtesy of FORD MOTOR COMPANY	C1111-32
C199B-15	Courtesy of FORD MOTOR COMPANY	C1111-22
C199B-22	Courtesy of FORD MOTOR COMPANY	C1111-33
C199B-16	Courtesy of FORD MOTOR COMPANY	C1111-23

Is the resistance less than 5 ohms?

Yes

GO to T6

No	With the aid of the wiring diagram, REPAIR the open circuit. CLEAR the Inverter System Controller (ISC) DTCs. REPEAT the self-test.

T6 CHECK THE GENERATOR RESOLVER CIRCUITS FOR A SHORT TO GROUND

Measure and record:

Positive Lead	Measurement / Action	Negative Lead
C199B-20	Courtesy of FORD MOTOR COMPANY	Ground
C199B-14	Courtesy of FORD MOTOR COMPANY	Ground
C199B-21	Courtesy of FORD MOTOR COMPANY	Ground
C199B-15	Courtesy of FORD MOTOR COMPANY	Ground
C199B-22	Courtesy of FORD MOTOR COMPANY	Ground
C199B-16	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance greater than 10K ohms?

Yes

GO to T7

No	With the aid of the wiring diagram, REPAIR the short circuit. CLEAR the Inverter System Controller (ISC) DTCs. REPEAT the self-test.

T7 CHECK THE GENERATOR RESOLVER CIRCUITS FOR A SHORT TO VOLTAGE

Ignition ON.

Measure and record:

Positive Lead	Measurement / Action	Negative Lead
C199B-20	Courtesy of FORD MOTOR COMPANY	Ground
C199B-14	Courtesy of FORD MOTOR COMPANY	Ground
C199B-21	Courtesy of FORD MOTOR COMPANY	Ground
C199B-15	Courtesy of FORD MOTOR COMPANY	Ground
C199B-22	Courtesy of FORD MOTOR COMPANY	Ground
C199B-16	Courtesy of FORD MOTOR COMPANY	Ground

Is any voltage present?

Yes	With the aid of the wiring diagram, REPAIR the short circuit. CLEAR the Inverter System Controller (ISC) DTCs. REPEAT the self-test.

GO to T9

T8 CHECK THE GENERATOR RESOLVER CIRCUITS FOR A SHORT TO THE EXTERNAL CABLE SHIELD

Ignition OFF.

Measure and record:

Positive Lead	Measurement / Action	Negative Lead
C199B-20	Courtesy of FORD MOTOR COMPANY	C199B-9
C199B-14	Courtesy of FORD MOTOR COMPANY	C199B-9
C199B-21	Courtesy of FORD MOTOR COMPANY	C199B-9
C199B-15	Courtesy of FORD MOTOR COMPANY	C199B-9
C199B-22	Courtesy of FORD MOTOR COMPANY	C199B-9
C199B-16	Courtesy of FORD MOTOR COMPANY	C199B-9

Is the resistance less than 5 ohms?

Yes

GO to T9

No	With the aid of the wiring diagram, REPAIR the short circuit. CLEAR the Inverter System Controller (ISC) DTCs. REPEAT the self-test.

T9 CHECK THE GENERATOR RESOLVER CIRCUITS FOR A SHORT TOGETHER

Measure and record:

Positive Lead	Measurement / Action	Negative Lead
C199B-20	Courtesy of FORD MOTOR COMPANY	C199B-14
C199B-20	Courtesy of FORD MOTOR COMPANY	C199B-21
C199B-20	Courtesy of FORD MOTOR COMPANY	C199B-15
C199B-20	Courtesy of FORD MOTOR COMPANY	C199B-22
C199B-20	Courtesy of FORD MOTOR COMPANY	C199B-16
C199B-14	Courtesy of FORD MOTOR COMPANY	C199B-21
C199B-14	Courtesy of FORD MOTOR COMPANY	C199B-15
C199B-14	Courtesy of FORD MOTOR COMPANY	C199B-22
C199B-14	Courtesy of FORD MOTOR COMPANY	C199B-16
C199B-21	Courtesy of FORD MOTOR COMPANY	C199B-15
C199B-21	Courtesy of FORD MOTOR COMPANY	C199B-22
C199B-21	Courtesy of FORD MOTOR COMPANY	C199B-16
C199B-15	Courtesy of FORD MOTOR COMPANY	C199B-22
C199B-15	Courtesy of FORD MOTOR COMPANY	C199B-16
C199B-22	Courtesy of FORD MOTOR COMPANY	C199B-16

Is the resistance greater than 10K ohms?

Yes

GO to T10

No	With the aid of the wiring diagram, REPAIR the short circuit. CLEAR the Inverter System Controller (ISC) DTCs. REPEAT the self-test.

T10 CHECK THE TRANSMISSION GENERATOR RESOLVER SENSORS FOR A SHORT TOGETHER

Measure and record:

Positive Lead	Measurement / Action	Negative Lead
Courtesy of FORD MOTOR COMPANY C1111 pin 31, component side	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY C1111 pin 32, component side
Courtesy of FORD MOTOR COMPANY C1111 pin 31, component side	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY C1111 pin 22, component side
Courtesy of FORD MOTOR COMPANY C1111 pin 31, component side	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY C1111 pin 33, component side
Courtesy of FORD MOTOR COMPANY C1111 pin 31, component side	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY C1111 pin 23, component side
Courtesy of FORD MOTOR COMPANY C1111 pin 21, component side	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY C1111 pin 32, component side
Courtesy of FORD MOTOR COMPANY C1111 pin 21, component side	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY C1111 pin 22, component side
Courtesy of FORD MOTOR COMPANY C1111 pin 21, component side	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY C1111 pin 33, component side
Courtesy of FORD MOTOR COMPANY C1111 pin 21, component side	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY C1111 pin 23, component side
Courtesy of FORD MOTOR COMPANY C1111 pin 32, component side	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY C1111 pin 33, component side
Courtesy of FORD MOTOR COMPANY C1111 pin 32, component side	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY C1111 pin 23, component side
Courtesy of FORD MOTOR COMPANY C1111 pin 22, component side	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY C1111 pin 33, component side
Courtesy of FORD MOTOR COMPANY C1111 pin 22, component side	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY C1111 pin 23, component side

Is the resistance greater than 10K ohms?

Yes

GO to T11

No	INSTALL a new transmission. REFER to: Transmission . CLEAR the Inverter System Controller (ISC) DTCs. REPEAT the self-test.

T11 CHECK THE TRANSMISSION GENERATOR RESOLVER RESISTANCES

Measure and record:

Positive Lead	Measurement / Action	Negative Lead
Courtesy of FORD MOTOR COMPANY C1111 pin 31, component side	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY C1111 pin 21, component side

Is the resistance between 12.4 and 18.6 ohms?

Yes

GO to T12

No	INSTALL a new transmission REFER to: Transmission . CLEAR the Inverter System Controller (ISC) DTCs. REPEAT the self-test.

T12 CHECK THE TRANSMISSION GENERATOR RESOLVER RESISTANCES

Ignition OFF.

Measure and record:

Positive Lead	Measurement / Action	Negative Lead
Courtesy of FORD MOTOR COMPANY C1111 pin 32, component side	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY C1111 pin 22, component side

Is the resistance between 19.6 and 29.4 ohms?

Yes

GO to T13

No	INSTALL a new transmission. REFER to: Transmission . CLEAR the Inverter System Controller (ISC) DTCs. REPEAT the self-test.

T13 CHECK THE TRANSMISSION GENERATOR RESOLVER RESISTANCES

Measure and record:

Positive Lead	Measurement / Action	Negative Lead
Courtesy of FORD MOTOR COMPANY C1111 pin 33, component side	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY C1111 pin 23, component side

Is the resistance between 18.4 and 27.6 ohms?

Yes

GO to T14

No	INSTALL a new transmission. REFER to: Transmission . CLEAR the Inverter System Controller (ISC) DTCs. REPEAT the self-test.

T14 CHECK THE GENERATOR RESOLVER SENSOR FOR A SHORT TO GROUND

Measure and record:

Positive Lead	Measurement / Action	Negative Lead
Courtesy of FORD MOTOR COMPANY C1111 pin 31, component side	Courtesy of FORD MOTOR COMPANY	Ground
Courtesy of FORD MOTOR COMPANY C1111 pin 21, component side	Courtesy of FORD MOTOR COMPANY	Ground
Courtesy of FORD MOTOR COMPANY C1111 pin 32, component side	Courtesy of FORD MOTOR COMPANY	Ground
Courtesy of FORD MOTOR COMPANY C1111 pin 22, component side	Courtesy of FORD MOTOR COMPANY	Ground
Courtesy of FORD MOTOR COMPANY C1111 pin 33, component side	Courtesy of FORD MOTOR COMPANY	Ground
Courtesy of FORD MOTOR COMPANY C1111 pin 23, component side	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance greater than 10K ohms?

Yes

GO to T15

No	INSTALL a new transmission. REFER to: Transmission . CLEAR the Inverter System Controller (ISC) DTCs. REPEAT the self-test.

T15 VISUAL INSPECTION OF THE HIGH VOLTAGE SYSTEM
- Remove the Inverter System Controller (ISC) side cover. When removing side cover, pull cover straight out approximately 2 inches before moving upwards or damage to the high voltage interlock connector may occur. REFER to: Inverter System Controller [SOBDMC] .
- Examine all the high voltage connections for damage and loose or broken conditions.
- Verify the high voltage terminal bolts are fully seated and torqued to 8 lb.ft (10.5 Nm)
Is a concern present?

Yes REPAIR as necessary. CLEAR the Inverter System Controller (ISC) DTCs and REPEAT the self-test.

No GO to T16

T16 CHECK FOR EXCESSIVE GENERATOR PHASE RESISTANCE

Measure and record:

Positive Lead	Measurement / Action	Negative Lead
Courtesy of FORD MOTOR COMPANY ISC/SOBDMC pin 6, component side	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY ISC/SOBDMC pin 7, component side
Courtesy of FORD MOTOR COMPANY ISC/SOBDMC pin 6, component side	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY ISC/SOBDMC pin 8, component side
Courtesy of FORD MOTOR COMPANY ISC/SOBDMC pin 7, component side	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY ISC/SOBDMC pin 8, component side

Is the resistance less than 5 ohms?

Yes

GO to T17

No	INSTALL a new Transmission. REFER to: Transmission . CLEAR the Inverter System Controller (ISC) DTCs. REPEAT the self-test.

T17 CHECK THE GENERATOR CIRCUITS FOR A SHORT TO GROUND

Measure and record:

Positive Lead	Measurement / Action	Negative Lead
Courtesy of FORD MOTOR COMPANY ISC/SOBDMC pin 6, component side	Courtesy of FORD MOTOR COMPANY	Ground
Courtesy of FORD MOTOR COMPANY ISC/SOBDMC pin 7, component side	Courtesy of FORD MOTOR COMPANY	Ground
Courtesy of FORD MOTOR COMPANY ISC/SOBDMC pin 8, component side	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance greater than 10K ohms?

Yes

GO to T18

No	INSTALL a new transmission. REFER to: Transmission . CLEAR the Inverter System Controller (ISC) DTCs. REPEAT the self-test.

T18 CHECK FOR CORRECT INVERTER SYSTEM CONTROLLER (ISC) OPERATION

Ignition OFF.

Disconnect and inspect all Inverter System Controller (ISC) connectors.

Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary

Reconnect the Inverter System Controller (ISC) connectors. Make sure they seat and latch correctly.

Install the Inverter System Controller (ISC) side cover. REFER to: Inverter System Controller [SOBDMC] .

Ignition ON.

CLEAR the Inverter System Controller (ISC) DTCs.

Ignition OFF.

Start the engine.

Using a diagnostic scan tool, run the Inverter System Controller (ISC) self-test.

Are any DTCs present?

Yes	For DTCs P0A71, P0A74 or P0A77 only, INSTALL a new transmission. REFER to: Transmission . CLEAR the Inverter System Controller (ISC) DTCs. REPEAT the self-test. For all other DTCs, DIAGNOSE all other Inverter System Controller (ISC) DTCs. REFER to Diagnostic Trouble Code (DTC) Chart .

No	The system is operating correctly at this time. The DTC may have been set due to high network traffic or an intermittent fault condition.