NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [13B-MSP]

id0103f2803000

24

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

DESCRIPTION

The 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 GND between A/C switch and PCM

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

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

24	A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY
DESCRIPTION	The 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 GND between A/C switch and PCM • Short to GND 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	Go to the applicable DTC inspection. (See DTC TABLE [13B-MSP].)
1		No	Go to the next step.
2	Start the engine and run it at idle. Turn the A/C switch on. Remove the A/C relay. Does the A/C magnetic clutch disengage?	Yes	Inspect for the following: • The A/C relay is stuck closed. • Short to GND circuit between the A/C relay and PCM terminal 1I. If both items normal, go to the next step.
2		No	Inspect if the circuit between A/C relay and the 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 GND circuit may be present. Does the A/C remain working?	Yes	Inspect for short to GND circuit between refrigerant pressure switch and PCM terminal 1AU.
3		No	Go to the next step.
4	Reconnect 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 GND circuit may be present. Does the A/C remain working?	Yes	Inspect the following: • Short to GND circuit between the A/C switch and the A/C amplifier • Short to GND 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. ― If the malfunction remains, inspect the related Service Bulletins and/or the On-line Repair Information and perform the repair or diagnosis.