Magnet Clutch Circuit

TROUBLE DIAGNOSIS


Magnet Clutch Circuit

SYMPTOM: Magnet clutch does not engage.

INSPECTION FLOW











SYSTEM DESCRIPTION
Unified meter and A/C amp. controls compressor operation by ambient temperature, intake air temperature and signal from ECM.

Low Temperature Protection Control
- Unified meter and A/C amp. will turn compressor ON or OFF as determined by a signal detected by ambient sensor and intake sensor.





- When ambient temperature is higher than -2�C (28�F), the compressor turns ON. The compressor turns OFF when ambient temperature is lower than -5�C (23�F).





- When intake air temperature is higher than 1�C (34�F), the compressor turns ON. The compressor turns OFF when intake air temperature is lower than -5�C (23�F).

DIAGNOSIS PROCEDURE FOR MAGNET CLUTCH
SYMPTOM: Magnet clutch does not engage when A/C switch is ON.
VQ35HR





VK45DE





1.CHECK AMBIENT SENSOR AND INTAKE SENSOR CIRCUIT
Check ambient sensor and intake sensor. Self-Diagnosis Function, see No. 9 and 11.
OK or NG
OK - GO TO 2.
NG-1 - Malfunctioning ambient sensor: Ambient Sensor Circuit.
NG-2 - Malfunctioning intake sensor: Intake Sensor Circuit.
2.PERFORM AUTO ACTIVE TEST
Perform IPDM E/R auto active test. Auto Active Test.
Does the magnet clutch operate?
YES-1 - WITH CONSULT-III: GO TO 5.
YES-2 - WITHOUT CONSULT-III: GO TO 6.
NO - Check 10A fuse (No. 79, located in IPDM E/R). IPDM E/R Terminal Arrangement, and GO TO 3.
3.CHECK CIRCUIT CONTINUITY BETWEEN IPDM E/R AND COMPRESSOR
1. Turn ignition switch OFF.
2. Disconnect IPDM E/R connector and compressor connector.





3. Check continuity between IPDM E/R harness connector E8 terminal 34 and compressor harness connector F24 terminal 1.

34 - 1: Continuity should exist.

OK or NG
OK - GO TO 4.
NG - Repair harness or connector.
4.CHECK MAGNET CLUTCH CIRCUIT





Check for operation sound when applying battery voltage direct current to terminal.
OK or NG
OK - 1. Replace IPDM E/R.
2. Go to self-diagnosis procedure Self-Diagnosis Function and perform self-diagnosis STEP-4.
Confirm that magnet clutch operation normal.
NG - 1. Replace compressor.
2. Go to self-diagnosis procedure Self-Diagnosis Function and perform self-diagnosis STEP-4.
Confirm that magnet clutch operation normal.
5.CHECK BCM INPUT (COMPRESSOR ON) SIGNAL
Check compressor ON/OFF signal in "Data monitor". Scan Tool Testing and Procedures.

A/C SWITCH ON: AIR COND SIG On
A/C SWITCH OFF: AIR COND SIG Off

OK or NG
OK - GO TO 8.
NG - GO TO 6.
6.CHECK REFRIGERANT PRESSURE SENSOR
WITH CONSULT-III
1. Start the engine.
2. Check voltage of refrigerant pressure sensor in "Data monitor". Pinout Values and Diagnostic Parameters(VQ35HR) or (VK45DE).
WITHOUT CONSULT-III
1. Start the engine.
2. Check voltage between ECM harness connector and ground.





OK or NG
OK-1 - WITH CONSULT-III: GO TO 7.
OK-2 - WITHOUT CONSULT-III: Repair harness or connector.
NG - Check refrigerant pressure sensor. Diagnosis Procedure (VQ35HR) or Diagnosis Procedure (VK45DE).
7.CHECK ECM INPUT (FAN ON) SIGNAL
Check FAN ON/OFF signal in "Data monitor". Scan Tool Testing and Procedures.

FAN SWITCH ON: HEATER FAN SW On
FAN SWITCH OFF: HEATER FAN SW Off

OK or NG
OK - GO TO 8.
NG - Repair harness or connector.
8.CHECK CAN COMMUNICATION
Check CAN communication. P1212 (VQ35HR) or (VK45DE).
- ECM � IPDM E/R
- ECM � Unified meter and A/C amp.
OK or NG
OK - Replace ECM.
NG - Repair or replace malfunctioning part(s).

COMPONENT INSPECTION

Refrigerant Pressure Sensor





The refrigerant pressure sensor is attached to the liquid tank.
Check that the A/C refrigerant pressure and the sensor output voltage are within the specified range as shown in the A/C operating condition figure. Diagnosis Procedure (VQ35HR) or (VK45DE).