NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [ZJ, Z6]

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NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [ZJ, Z6]

B3E010318881W57

24 | A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY.
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DESCRIPTION | The A/C compressor magnetic clutch does not disengage.
POSSIBLE CAUSE | • Stuck engagement A/C compressor magnetic clutch • A/C relay is stuck closed. • Short to GND in wiring harness between A/C switch and PCM • Short to GND in wiring harness between A/C relay and PCM • Short to battery power in A/C relay to magnetic clutch circuit shorted to battery power

Diagnostic procedure

STEP | INSPECTION | RESULTS | ACTION
--- | --- | --- | ---
1 | Connect the WDS or equivalent to the DLC-2. Retrieve any continuous memory, KOEO and KOER DTCs using WDS or equivalent. Are there any DTCs displayed? | Yes | DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [ZJ, Z6].)
No | No DTC is displayed: Go to the next step.
2 | Start the engine and idle it. Turn the A/C switch on. Remove the A/C relay. Does the A/C magnetic clutch disengage? | Yes | Inspect for the following: • A/C relay is stuck closed. • Short to GND in wiring harness between A/C relay and PCM terminal 1AL. If both items normal, go to the next step.
No | Inspect if circuit between the A/C relay and the magnetic clutch shorts to battery power circuit. • If circuit is normal, inspect the magnetic clutch stuck engagement or clearance.

3

Connect the WDS or equivalent to the DLC-2.
Access AC_REQ PID.
Start the engine and turn the A/C switch on.
Read AC_REQ PID while disconnecting the refrigerant pressure switch connector.

  Note

  • AC_REQ PID should read Off when disconnecting connector. If AC_REQ PID remains On, short to GND may be present.

Does AC_REQ PID remain On?

Yes

Inspect for short to GND in wiring harness between the refrigerant pressure switch and the PCM terminal 1Q.

No | Go to the next step.

4

Reconnect the refrigerant pressure switch connector.
Read AC_REQ PID while turning off the A/C switch.

  Note

  • AC_REQ PID should read Off when turning A/C switch off. If AC_REQ PID remains On, short to GND may be present.

Does AC_REQ PID remain On?

Yes

Inspect following:
• Short to GND in wiring harness between A/C switch and A/C amplifier
• Short to GND in wiring harness between A/C amplifier and refrigerant pressure switch

No | Inspect for stuck closed the A/C switch.

5

Verify test results.
• If normal, return to diagnostic index to service any additional symptoms.
(See ENGINE SYMPTOM TROUBLESHOOTING [ZJ, Z6].)
• If malfunction remains, inspect related Service information perform repair or diagnosis.

  - If vehicle repaired, troubleshooting completed.
  - If vehicle not repaired or additional diagnostic information not available, replace the PCM.
  (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [ZJ, Z6].)