Test Procedure

Three Speed Fan Operation
Although the PCM output circuits are called low, medium, and high fan control (FC), cooling fan operation is controlled by a combination of these outputs.

Refer to ENGINE CONTROL COMPONENTS for system information.

Fig 1: Identifying Low Fan Control (LFC) Relay Connector
Courtesy of MAZDA MOTORS CORP.

Fig 2: Identifying Medium Fan Control (MFC) Relay Connector
Courtesy of MAZDA MOTORS CORP.

Fig 3: Identifying High Fan Control (HFC) Relay Connector
Courtesy of MAZDA MOTORS CORP.

Fig 4: Identifying Left Fan Motor Connector
Courtesy of MAZDA MOTORS CORP.

Fig 5: Identifying Right Fan Motor Connector
Courtesy of MAZDA MOTORS CORP.

Fig 6: Identifying Powertrain Control Module (PCM) Connector
Courtesy of MAZDA MOTORS CORP.
KF1: CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS) P0480, P0481 AND P0482
- Are any of the following DTCs present during PCM or transaxle control module (TCM) self-test P0480, P0481, or P0482?
- Yes: For KOEO and KOER DTC P0480, GO to KF2.
  For KOEO and KOER DTC P0481, GO to KF12.
  
  For KOEO and KOER DTC P0482, GO to KF7.
  
  For continuous memory DTC P0480, GO to KF17.
  
  For continuous memory DTC P0481, GO to KF19.
  
  For continuous memory DTC P0482, GO to KF21.
- No: For cooling fan always runs, GO to KF23.
  For cooling fan does not operate, GO to KF26.

KF2: KOEO AND KOER DTC P0480: CHECK THE VPWR VOLTAGE TO LOW SPEED FC RELAY

LFC Relay connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

(+) LFC Relay Connector, Harness Side	(-) Vehicle Battery
VPWR - Pin 2	Negative terminal

Is the voltage greater than 10.5 V?

Yes: GO to KF3.
No: REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

KF3: CHECK FOR LFC CIRCUIT CYCLING

NOTE: During KOEO on demand self-test, the LFC circuit will be cycled on and off.

Connect a non-powered test lamp between:

(+) LFC Relay Connector, Harness Side	(-) LFC Relay Connector, Harness Side
VPWR - Pin 2	LFC - Pin 1

Carry out the PCM KOEO on demand self-test.
Does the test lamp illuminate on and off during the KOEO on demand self-test?

Yes: INSTALL a new LFC relay. CLEAR the DTCs. REPEAT the self-test.
No: REMOVE the test lamp.
GO to KF4.

KF4: CHECK THE LFC CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS

Key in OFF position.
PCM connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

(+) LFC Relay Connector, Harness Side	(-) Vehicle Battery
LFC - Pin 1	Negative terminal

Is the voltage less than 1 V?

Yes: GO to KF5.
No: REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.

KF5: CHECK THE LFC CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS

Measure the resistance between:

(+) LFC Relay Connector, Harness Side	(-) Vehicle Battery
LFC - Pin 1	Negative terminal

Is the resistance greater than 10K ohms?

Yes: GO to KF6.
No: REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.

KF6: CHECK THE LFC CIRCUIT FOR AN OPEN IN THE HARNESS

Measure the resistance between:

(+) LFC Relay Connector, Harness Side	(-) PCM Connector, Harness Side
LFC - Pin 1	LFC - Pin B38

Is the resistance less than 5 ohms?

Yes: GO to KF32.
No: REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

KF7: KOEO AND KOER DTC P0482: CHECK THE VPWR VOLTAGE TO MEDIUM SPEED FC RELAY

MFC Relay connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

(+) MFC Relay Connector, Harness Side	(-)
VPWR - Pin 2	Ground

Is the voltage greater than 10.5 V?

Yes: GO to KF8.
No: REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

KF8: CHECK FOR MFC CIRCUIT CYCLING

NOTE: During KOEO on demand self-test, the MFC circuit will be cycled on and off.

Connect a non-powered test lamp between:

(+) MFC Relay Connector, Harness Side	(-) MFC Relay Connector, Harness Side
VPWR - Pin 2	MFC - Pin 1

Carry out the PCM KOEO on demand self-test.
Does the test lamp illuminate on and off during the KOEO on demand self-test?

Yes: INSTALL a new MFC relay. CLEAR the DTCs. REPEAT the self-test.
No: REMOVE the test lamp.
GO to KF9.

KF9: CHECK THE MFC CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS

Key in OFF position.
PCM connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

(+) MFC Relay Connector, Harness Side	(-)
MFC - Pin 1	Ground

Is the voltage less than 1 V?

Yes: GO to KF10.
No: REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.

KF10: CHECK THE MFC CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS

Key in OFF position.

Measure the resistance between:

(+) MFC Relay Connector, Harness Side	(-)
MFC - Pin 1	Ground

Is the resistance greater than 10K ohms?

Yes: GO to KF11.
No: REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.

KF11: CHECK THE MFC CIRCUIT FOR AN OPEN IN THE HARNESS

Measure the resistance between:

(+) MFC Relay Connector, Harness Side	(-) PCM Connector, Harness Side
MFC - Pin 1	MFC - Pin B33

Is the resistance less than 5 ohms?

Yes: GO to KF32.
No: REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

KF12: KOEO AND KOER DTC P0481: CHECK THE VPWR VOLTAGE TO THE HIGH SPEED FC RELAY

HFC Relay connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

(+) HFC Relay Connector, Harness Side	(-)
VPWR - Pin 2	Ground

Is the voltage greater than 10.5 V?

Yes: GO to KF13.
No: REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

KF13: CHECK FOR HFC CIRCUIT CYCLING

NOTE: During KOEO on demand self-test, the HFC circuit will be cycled on and off.

Connect a non-powered test lamp between:

(+) HFC Relay Connector, Harness Side	(-) HFC Relay Connector, Harness Side
VPWR - Pin 2	HFC - Pin 1

Carry out the KOEO on demand self-test.
Does the test lamp illuminate on and off during the KOEO on demand self-test?

Yes: INSTALL a new HFC relay. CLEAR the DTCs. REPEAT the self-test.
No: REMOVE the test lamp.
GO to KF14.

KF14: CHECK THE HFC CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS

PCM connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

(+) HFC Relay Connector, Harness Side	(-) Vehicle Battery
HFC - Pin 1	Negative terminal

Is the voltage less than 1 V?

Yes: GO to KF15.
No: REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.

KF15: CHECK THE HFC CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS

Measure the resistance between:

(+) HFC Relay Connector, Harness Side	(-) Vehicle Battery
HFC - Pin 1	Negative terminal

Is the resistance greater than 10K ohms?

Yes: GO to KF16.
No: REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.

KF16: CHECK THE HFC CIRCUIT FOR AN OPEN IN THE HARNESS

Measure the resistance between:

(+) HFC Relay Connector, Harness Side	(-) PCM Connector, Harness Side
HFC - Pin 1	HFC - Pin B37

Is the resistance less than 5 ohms?

Yes: GO to KF32.
No: REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

KF17: CONTINUOUS MEMORY DTC P0480: CHECK THE LFC CIRCUIT FOR AN INTERMITTENT OPEN OR SHORT TO VOLTAGE

A/C and defrost off.
Left Fan Motor connector disconnected.
Right Fan Motor connector disconnected.

Connect a non-powered test lamp between:

(+) Left Fan Motor Connector, Harness Side	(-) Left Fan Motor Connector, Harness Side
LSFAN PWR - Pin 1, 2	GND - Pin 3

Key ON, engine OFF.
Enter output test mode. Refer to OUTPUT TEST MODE (OTM) .
Command the low speed fan ON.
Observe the test lamp for an indication of a concern while carrying out the following. Note that the lamp turns off when a concern is detected.
- Shake, wiggle, and bend the LFC circuit(s).
- Shake, wiggle, and bend the VPWR circuit to the LFC relay.
- Lightly tap on the low speed FC relay to simulate road shock
Is a concern present?

Yes: ISOLATE the concern and REPAIR as necessary.
No: GO to KF18.

KF18: CHECK THE LFC CIRCUIT FOR AN INTERMITTENT SHORT TO GROUND
- Key ON, engine OFF.
- Command the outputs OFF.
- Observe the test lamp for an indication of a concern while completing the following. Note that the lamp turns on when a concern is detected.
  - Shake, wiggle, and bend the LFC circuit(s).
  - Lightly tap on the LFC relay to simulate road shock
- Is a concern present?
- Yes: ISOLATE the concern and REPAIR as necessary.
- No: Unable to duplicate or identify the concern at this time.
  GO to PINPOINT TEST Z .

KF19: CONTINUOUS MEMORY DTC P0481: CHECK THE HFC CIRCUIT FOR AN INTERMITTENT OPEN OR SHORT TO VOLTAGE

A/C and defrost off.
Left Fan Motor connector disconnected.
Right Fan Motor connector disconnected.

Connect a non-powered test lamp between:

(+) Right Fan Motor Connector, Harness Side	(-) Right Fan Motor Connector, Harness Side
HSFAN PWR - Pin 2	GND- Pin 1

Key ON, engine OFF.
Enter output test mode. Refer to OUTPUT TEST MODE (OTM) .
Command the high speed fan ON.
Observe the test lamp for an indication of a concern while completing the following. Note that the lamp turns on when a concern is detected.

Shake, wiggle, and bend the HFC circuit(s).
Shake, wiggle, and bend the VPWR circuit to the HFC relay.
Lightly tap on the high speed FC relay to simulate road shock
Is a concern present?

Yes: ISOLATE the concern and REPAIR as necessary.
No: GO to KF20.

KF20: CHECK THE HFC CIRCUIT FOR AN INTERMITTENT SHORT TO GROUND
- Key ON, engine OFF.
- Command the outputs OFF.
- Observe the test lamp for an indication of a concern while completing the following. Note that the lamp turns on when a concern is detected.
- Shake, wiggle, and bend the HFC circuit(s).
- Is a concern present?
- Yes: ISOLATE the concern and REPAIR as necessary.
- No: Unable to duplicate or identify the concern at this time. GO to PINPOINT TEST Z .

KF21: CONTINUOUS MEMORY DTC P0482: CHECK THE MFC CIRCUIT FOR AN INTERMITTENT OPEN OR SHORT TO VOLTAGE

A/C and defrost off.
Left Fan Motor connector disconnected.
Right Fan Motor connector disconnected.

Connect a non-powered test lamp between:

(+) Right Fan Motor Connector, Harness Side	(-) Right Fan Motor Connector, Harness Side
MSFAN PWR - Pin 2	GND- Pin 1

Key ON, engine OFF.
Enter output test mode. Refer to OUTPUT TEST MODE (OTM) .
Command the low speed fan ON.
Observe the test lamp for an indication of a concern while carrying out the following. Note that the lamp turns off when a concern is detected.
- Shake, wiggle, and bend the MFC circuit(s).
- Shake, wiggle, and bend the VPWR circuit to the MFC relay.
- Medium speed FC relay low speed FC relay
Is a concern present?

Yes: ISOLATE the concern and REPAIR as necessary.
No: GO to KF22.

KF22: CHECK THE MFC CIRCUIT FOR AN INTERMITTENT SHORT TO GROUND
- Key ON, engine OFF.
- Command the outputs OFF.
- Observe the test lamp for an indication of a concern while completing the following. Note that the lamp turns off when a concern is detected.
- Shake, wiggle, and bend the MFC circuit(s).
- Is a concern present?
- Yes: ISOLATE the concern and REPAIR as necessary.
- No: Unable to duplicate or identify the concern at this time.
  GO to PINPOINT TEST Z .
KF23: COOLING FAN ALWAYS RUNS (NO DTCS): VERIFY THE FAN IS NOT ON BECAUSE OF A/C HIGH PRESSURE SWITCH INPUT TO THE PCM
- Key ON, engine running.
- Access the PCM and monitor the ACP PID.
- Is the PID state CLOSED?
- Yes: The PCM will turn the fan on when the medium pressure, normally open contacts of the ACHP switch are closed.
  GO to KF24.
- No: Input OK.
  GO to KF26.
KF24: CHECK THE A/C HIGH PRESSURE SWITCH (A/CHPSW) (MEDIUM PRESSURE, NORMALLY OPEN CONTACTS)
- A/CHPSW connector disconnected.
- Key ON, engine OFF.
- Access the PCM and monitor the ACP PID.
- Is the PID state CLOSED?
- Yes: GO to KF25.
- No: RECONNECT A/CHPSW.
  REFER to the CLIMATE CONTROL SYSTEM OPERATION -- HYBRID to diagnose the A/C system.
  
  If OK, INSTALL a new A/CHPSW.
  
  CLEAR the DTCs. REPEAT the self-test.

KF25: CHECK THE A/CPSW CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS

Key in OFF position.
PCM connector disconnected.

Measure the resistance between:

(+) A/CHPSW Connector, Harness Side	(-)
A/CPSW	Ground

Is the resistance greater than 10K ohms?

Yes: VERIFY the results of the previous test steps. RETURN to SYMPTOM CHARTS to continue diagnosis.
GO to KF32.
No: REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.

KF26: CHECK THE VPWR VOLTAGE TO LOW SPEED FC RELAY

LFC Relay connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

(+) LFC Relay Connector, Harness Side	(-) Vehicle Battery
VPWR - Pin 2	Negative terminal

Is the voltage greater than 10.5 V?

Yes: GO to KF27.
No: REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

KF27: CHECK FOR LFC CIRCUIT CYCLING

NOTE: During KOEO on demand self-test, the LFC circuit will be cycled on and off.

Connect a non-powered test lamp between:

(+) LFC Relay Connector, Harness Side	(-) LFC Relay Connector, Harness Side
VPWR - Pin 2	LFC - Pin 1

Carry out the PCM KOEO on demand self-test.
Does the test lamp illuminate on and off during the KOEO on demand self-test?

Yes: GO to KF28.
No: REMOVE the test lamp.
GO to KF4.

KF28: CHECK THE VPWR VOLTAGE TO MEDIUM SPEED FC RELAY

Key in OFF position.
MFC Relay connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

(+) MFC Relay Connector, Harness Side	(-)
VPWR - Pin 2	Ground

Is the voltage greater than 10.5 V?

Yes: GO to KF29.
No: REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

KF29: CHECK FOR MFC CIRCUIT CYCLING

NOTE: During KOEO on demand self-test, the MFC circuit will be cycled on and off.

Connect a non-powered test lamp between:

(+) MFC Relay Connector, Harness Side	(-) MFC Relay Connector, Harness Side
VPWR - Pin 2	MFC - Pin 1

Carry out the PCM KOEO on demand self-test.
Does the test lamp illuminate on and off during the KOEO on demand self-test?

Yes: GO to KF30.
No: REMOVE the test lamp.
GO to KF9.

KF30: CHECK THE VPWR VOLTAGE TO HIGH SPEED FC RELAY

Key in OFF position.
HFC Relay connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

(+) HFC Relay Connector, Harness Side	(-)
VPWR - Pin 2	Ground

Is the voltage greater than 10.5 V?

Yes: GO to KF31.
No: REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

KF31: CHECK FOR HFC CIRCUIT CYCLING

NOTE: During KOEO on demand self-test, the HFC circuit will be cycled on and off.

Connect a non-powered test lamp between:

(+) HFC Relay Connector, Harness Side	(-) HFC Relay Connector, Harness Side
VPWR - Pin 2	HFC - Pin 1

Carry out the KOEO on demand self-test.
Does the test lamp illuminate on and off during the KOEO on demand self-test?

Yes: The PCM primary FC circuits are OK.
REFER to the appropriate Component Testing article to check the relay(s).

INSTALL a new FC relay if necessary.

To check the secondary FC circuits,

REFER to the COOLING SYSTEM - HYBRID .
No: REMOVE the test lamp.
GO to KF14.

KF32: CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Visually inspect for:
  - pushed out pins.
  - corrosion.
- Connect all the PCM connectors and make sure they seat correctly.
- Carry out the PCM self-test and verify the concern is still present.
- Is the concern still present?
- Yes: INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) .
- No: The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.