Magnet Clutch Circuit (If Equipped)

TROUBLE DIAGNOSIS


Magnet Clutch Circuit (If Equipped)

SYMPTOM: Magnet clutch does not engage.

INSPECTION FLOW
1. CONFIRM SYMPTOM BY PERFORMING OPERATIONAL CHECK - MAGNET CLUTCH
1. Turn ignition switch ON.
2. Turn blower control dial to the desired position.
3. Press the A/C switch. A/C indicator will turn on.
4. Confirm that the compressor clutch engages (sound or visual inspection).
Can the symptom be duplicated?
YES >> GO TO 3.
NO >> GO TO 2.
2. CHECK FOR ANY SYMPTOMS
Perform a complete operational check for any symptoms. Refer to Operational Check.
Does another symptom exist?
YES >> Refer to Initial Inspection and Diagnostic Overview.
NO >> System OK.
3. CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 4.
4. CHECK COMPRESSOR BELT TENSION
Check compressor belt tension. Refer to Testing and Inspection (MR20DE) or Testing and Inspection (QR25DE).
OK or NG
OK >> GO TO 5.
NG >> Adjust or replace A/C compressor belt.
5. CHECK REFRIGERANT PRESSURE
Check refrigerant pressure with manifold gauge connected. Refer to Insufficient Cooling.
OK or NG
OK >> GO TO 6.
NG >> Perform trouble diagnosis for unusual pressure. Refer to Insufficient Cooling.
6. CHECK MAGNET CLUTCH CIRCUIT
Perform diagnostic procedure for the magnetic clutch. Refer to "DIAGNOSTIC PROCEDURE".
OK or NG
OK >> If the symptom still exists, perform a complete operational check. Refer to Operational Check. If other symptoms exist, refer to Initial Inspection and Diagnostic Overview.
NG >> Repair as necessary.

SYSTEM DESCRIPTION
Front air control controls compressor operation by a signal from ECM.

DIAGNOSTIC PROCEDURE
SYMPTOM: Magnet clutch does not engage when A/C switch is ON.





1. CHECK CIRCUIT CONTINUITY BETWEEN A/C RELAY IN IPDM E/R AND COMPRESSOR





1. Disconnect IPDM E/R connector E43 and compressor connector.
2. Check continuity between A/C compressor harness connector F3 (B) terminal 2 and IPDM E/R harness connector E43 (A) terminal 11.





If OK, check harness for short to ground.
OK or NG
OK >> GO TO 2.
NG >> Repair harness or connector.
2. CHECK POWER SUPPLY FOR COMPRESSOR





1. Reconnect IPDM E/R harness connectors.
2. Start engine and press A/C switch.
3. Check voltage between A/C compressor harness connector F3 terminal 2 and ground.





OK or NG
OK >> Check magnet clutch coil.
1. If NG, replace magnet clutch. Refer to Removal and Replacement or Removal and Replacement.
2. If OK, check A/C compressor mounting points for looseness or corrosion and repair as necessary.
NG >> GO TO 3.
3. CHECK FUSE IN IPDM E/R
Check 10A fuse [No. 42 located at the IPDM E/R].
OK or NG
OK >> GO TO 4.
NG >> Replace fuse and check IPDM E/R for short circuit. Replace if necessary.
4. CHECK CONTINUITY BETWEEN BCM AND FRONT AIR CONTROL
1. Disconnect BCM connector M18 and front air control connector M33.





2. Check continuity between BCM harness connector M18 (A) terminals 27, 28 and front air control connector M33 (B) terminals 40, 39.





OK or NG
OK >> GO TO 5.
NG >> Repair harness or connector.
5. CHECK REFRIGERANT PRESSURE SENSOR INPUT SIGNAL





Check voltage between ECM harness connector F25 terminal 41 [*1(with MR20DE)], 39 [(*2 with QR25DE)] and ground.





OK or NG
OK >> GO TO 6.
NG >> 1. Repair harness or connector.
2. Confirm that magnet clutch operation is normal.
6. CHECK REFRIGERANT PRESSURE SENSOR
Refer to For California(MR20DE) or Refrigerant Pressure Sensor (QR25DE).
OK or NG
OK >> GO TO 7.
NG >> Replace refrigerant pressure sensor. Refer to Service and Repair.
7. CHECK COMPRESSOR ON SIGNAL





Check voltage between front air control connector M33 terminal 40 and ground, with A/C compressor ON and with A/C compressor OFF.





OK or NG
OK >> GO TO 8.
NG >>
- When A/C compressor is ON and voltage is not approx. 0V, Replace front air control. Refer to Service and Repair.
- When A/C compressor is OFF and voltage is not approx. 5V, BCM is malfunctioning.
8. CHECK CAN COMMUNICATION CIRCUITS
Check CAN communication circuits between BCM to ECM and between ECM to IPDM E/R. Refer to Symptom When Error Occurs In CAN Communication System.
OK or NG
OK >> ECM malfunctioning.
NG >> Repair or replace component based on the result of diagnosis.