NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [L8, LF]


24	A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY.
DESCRIPTION	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 circuit to battery power in A/C relay to magnetic clutch


STEP	INSPECTION	RESULTS	ACTION
1	Connect the M-MDS to the DLC-2. Retrieve any continuous memory, KOEO and KOER DTCs using M-MDS. Are there any DTCs displayed?	Yes	DTC is displayed: Go to appropriate DTC inspection. (See DTC TABLE [L8, LF].)
1		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 following: • The A/C relay is stuck closed. • Short to GND in wiring harness between A/C relay and PCM terminal 1I. If both items normal, go to the next step.
2		No	Inspect if circuit between the A/C relay and magnetic clutch shorts to battery power circuit. • If the circuit is normal, inspect for magnetic clutch stuck engagement or clearance.
3	Connect M-MDS to DLC-2. Access AC_REQ PID. Start engine and turn A/C switch on. Read AC_REQ PID while disconnecting 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 refrigerant pressure switch and PCM terminal 1AU.
3		No	Go to the next step.
4	Reconnect refrigerant pressure switch connector. Read AC_REQ PID while turning off 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 the following: • Short to GND in wiring harness between the A/C switch and A/C amplifier • Short to GND in wiring harness between the A/C amplifier and refrigerant pressure switch
4		No	Inspect for stuck closed A/C switch.
5	Verify test results. • If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [L8, LF].) • 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 PCM REMOVAL/INSTALLATION [L8, LF].)