NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [MZR 2.3 DISI Turbo]

id0103e2803000

24

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

DESCRIPTION

•  A/C compressor magnetic clutch does not disengage.

POSSIBLE CAUSE

•  PCM, instrument cluster or climate control unit DTC is stored.

•  Short to power supply in wiring harness between A/C relay and magnetic clutch

•  A/C compressor magnetic clutch engagement is stuck.

•  A/C relay malfunction

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

•  Short to ground in wiring harness between climate control unit terminal 2P and instrument cluster (Manual air conditioner)

•  Climate control unit malfunction

24	A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY
DESCRIPTION	• A/C compressor magnetic clutch does not disengage.
POSSIBLE CAUSE	• PCM, instrument cluster or climate control unit DTC is stored. • Short to power supply in wiring harness between A/C relay and magnetic clutch • A/C compressor magnetic clutch engagement is stuck. • A/C relay malfunction • Short to ground in wiring harness between A/C relay and PCM • Short to ground in wiring harness between climate control unit terminal 2P and instrument cluster (Manual air conditioner) • Climate control unit malfunction

Diagnostic procedure

STEP	INSPECTION	RESULTS	ACTION
1	Switch the ignition to ON (engine off). Perform the PCM, instrument cluster and climate control unit DTC inspection using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.3 DISI Turbo].) (See DTC INSPECTION [INSTRUMENT CLUSTER].) (See DTC DISPLAY [FULL-AUTO AIR CONDITIONER].) Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [MZR 2.3 DISI Turbo].) (See DTC TABLE [INSTRUMENT CLUSTER].) (See DTC TABLE [FULL-AUTO AIR CONDITIONER].)
1		No	Go to the next step.
2	Start the engine and idle it. Turn the A/C switch on with blower switch is on. Remove the A/C relay. Does the A/C magnetic clutch disengage?	Yes	Go to Step 4.
2		No	Go to the next step.
3	A/C relay is removed. Switch the ignition to off. Disconnect the A/C compressor connector. Switch the ignition to ON (engine off). Measure the voltage at the A/C compressor terminal A (wiring harness-side). Is the voltage B+?	Yes	Repair or replace the wiring harness for a possible short to power supply.
3		No	Replace the A/C compressor (A/C magnetic clutch engagement is stuck). (See A/C COMPRESSOR REMOVAL/INSTALLATION.)
4	Inspect the A/C relay. (See RELAY INSPECTION.) Is there any malfunction?	Yes	Replace the A/C relay.
4		No	Go to the next step.
5	Access the ACCS PID using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.3 DISI Turbo].) Start the engine and idle it. Turn the A/C switch on and off with blower switch is on. Is the ACCS PID value always ON?	Yes	Manual air conditioner: • Go to the next step. Full-auto air conditioner: • Replace the climate control unit (A/C switch signal is always on). (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].)
5		No	Inspect for short to ground in wiring harness between PCM terminal 1I and A/C relay. Repair or replace the suspected wiring harness.
6	Switch the ignition to off. Disconnect the instrument cluster and climate control unit connectors. Inspect for continuity between climate control unit terminal 2P (wiring harness-side) and body ground. Is there continuity?	Yes	Repair or replace the suspected wiring harness.
6		No	Replace the climate control unit (A/C switch signal is always on). (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER].)
7	Verify test results. • If normal, return to the diagnostic index to service any additional symptoms. • If a malfunction remains, inspect the related Service Information and perform the repair or diagnosis. ― If the vehicle is repaired, troubleshooting is completed. ― If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later calibration is available. Retest.