NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [L8, LF, L5]

id010346803000

24

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

DESCRIPTION

A/C compressor magnetic clutch does not disengage.

POSSIBLE CAUSE

•  A/C compressor magnetic clutch engagement is stuck.

•  A/C relay is stuck closed.

•  Short to ground in wiring harness between A/C switch and PCM

•  Short to ground in wiring harness between A/C relay and PCM

•  Short circuit to battery power in A/C relay to magnetic clutch

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

Diagnostic procedure

STEP	INSPECTION	RESULTS	ACTION
1	Connect the M-MDS to the DLC-2. Switch the ignition to ON (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [L8, LF, L5].)
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 the following: • A/C relay is stuck closed. • Short to ground in the wiring harness between the A/C relay and PCM terminal 1I. If both items are normal, go to the next step.
2		No	Inspect if the circuit between the A/C relay and magnetic clutch shorts to the battery power circuit. If the circuit is normal, inspect the magnetic clutch for stuck engagement or clearance.
3	Disconnect the refrigerant pressure switch connector. Start the engine and turn the A/C switch on. Note • The A/C should not work when disconnecting the connector. If the A/C remains working, a short to the ground circuit may be present. Does the A/C remain working?	Yes	Inspect for a short to ground in the wiring harness between the refrigerant pressure switch and PCM terminal 1AW.
3		No	Go to the next step.
4	Reconnect the refrigerant pressure switch connector. Turn off the A/C switch. Note • The A/C should not work when turning the A/C switch off. If the A/C remains working, a short to the ground circuit may be present. Does A/C remain working?	Yes	Inspect the following: • Short to ground in the wiring harness between the A/C switch and the A/C amplifier • Short to the ground circuit between the A/C amplifier and the refrigerant pressure switch
4		No	Inspect whether the A/C switch is stuck closed.
5	• Verify test results. ― If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [L8, LF, L5].) ― If the malfunction remains, inspect the related Service Information and perform repair or diagnosis. • If the vehicle is repaired, troubleshooting is completed. • If the vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [L8, LF, L5].)