NO.23 A/C IS ALWAYS ON/A/C COMPRESSOR RUNS CONTINUOUSLY [F2]

id010394851600

23

A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY.

DESCRIPTION

The A/C compressor magnetic clutch does not disengage.

POSSIBLE CAUSE

•  Stuck engagement

•  A/C relay is stuck closed.

•  Short to ground between A/C switch and PCM

•  Short to ground circuit between A/C relay and PCM

•  A/C relay to magnetic clutch circuit shorted to battery power

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

Diagnostic procedure

STEP	INSPECTION	RESULTS	ACTION
1	Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: • Go to appropriate the DTC inspection. (See DTC TABLE [F2].)
1		No	No DTC is displayed: • Inspect instrument cluster operation. (See INSTRUMENT CLUSTER INSPECTION.)
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 ground circuit between A/C relay and PCM terminal 1J. If both items normal, go to the next step.
2		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 M-MDS to the DLC-2. Access ACSW PID. Start the engine and turn the A/C switch on. Read ACSW PID while disconnecting the refrigerant pressure switch connector. Note • ACSW PID should read Off when disconnecting connector. If ACSW PID remains On, short to ground circuit may be present. Does ACSW PID remain On?	Yes	Inspect for short to ground circuit between the refrigerant pressure switch and the PCM terminal 1Q.
3		No	Go to the next step.
4	Reconnect the refrigerant pressure switch connector. Read ACSW PID while turning off the A/C switch. Note • ACSW PID should read Off when turning A/C switch off. If ACSW PID remains On, short to ground circuit may be present. Does ACSW PID remain On?	Yes	Inspect following: • Short to ground circuit between A/C switch and A/C amplifier • Short to ground circuit between A/C amplifier and refrigerant pressure switch
4		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 [F2].) ― If malfunction remains, inspect related Service Information and perform repair or diagnosis. • If vehicle is repaired, troubleshooting completed. • If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [F2].)