NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [MZR 2.0 DISI i-stop]

id0103d3803000

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, multi information display or climate control unit (full-auto air conditioner) DTC is stored.
•  Short to power supply in wiring harness between magnetic clutch terminal A and A/C relay terminal D
•  Magnetic clutch engagement is stuck.
•  Climate control unit malfunction (Climate control unit always transmits A/C request signal)
•  A/C relay is stuck closed.
•  Short to ground in wiring harness between A/C relay terminal E and PCM terminal 1I

*1  :Vehicles without advanced keyless entry and push button start system
*2  :Vehicles with advanced keyless entry and push button start system

Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION
1
Connect the M-MDS to the DLC-2.
Retrieve the PCM, instrument cluster, multi information display and climate control unit (full-auto air conditioner) DTCs using the M-MDS.
(See ON-BOARD DIAGNOSTIC TEST [MZR 2.0 DISI i-stop].)
(See DTC INSPECTION [INSTRUMENT CLUSTER].)
(See DTC INSPECTION [INFORMATION DISPLAY/MULTI INFORMATION DISPLAY].)
(See DTC DISPLAY [FULL-AUTO AIR CONDITIONER].)
Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [MZR 2.0 DISI i-stop].)
(See DTC TABLE [INSTRUMENT CLUSTER].)
(See DTC TABLE [INFORMATION DISPLAY/MULTI INFORMATION DISPLAY].)
(See DTC TABLE [FULL-AUTO AIR CONDITIONER].)
No
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 magnetic clutch disengage?
Yes
Go to Step 5.
No
Go to the next step.
3
Switch the ignition to off.
Disconnect the magnetic clutch connector.
Start the engine and idle it.
Does the magnetic clutch disengage?
Yes
Inspect for short to power supply circuit between magnetic clutch terminal A and A/C relay terminal D.
Repair or replace the wiring harness for a possible short to power supply if necessary.
No
Go to the next step.
4
Verify the magnetic clutch clearance.
(See MAGNETIC CLUTCH ADJUSTMENT [FULL-AUTO AIR CONDITIONER].)
Is the magnetic clutch clearance normal?
Yes
Inspect the magnetic clutch for stuck.
(See MAGNETIC CLUTCH INSPECTION [FULL-AUTO AIR CONDITIONER].)
Replace the magnetic clutch if necessary.
(See MAGNETIC CLUTCH DISASSEMBLY/ASSEMBLY [FULL-AUTO AIR CONDITIONER].)
No
Adjust the magnetic clutch clearance.
(See MAGNETIC CLUTCH ADJUSTMENT [FULL-AUTO AIR CONDITIONER].)
5
Access the PCM PID ACCS using the M-MDS.
(See ON-BOARD DIAGNOSTIC TEST [MZR 2.0 DISI i-stop].)
Monitor the PID ACCS while turning on and off the air conditioner by switching the control panel.
Is the PID value always ON?
Yes
Climate control unit always transmits A/C request signal.
•  Replace the climate control unit.
No
Go to the next step.
6
Inspect the A/C relay.
(See RELAY INSPECTION.)
Is there any malfunction?
Yes
Replace the A/C relay.
No
Inspect for short to ground circuit between A/C relay terminal E and PCM terminal 1I.
Repair or replace the wiring harness for a possible short to ground if necessary.
7
Verify the test results.
•  If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.0 DISI i-stop].)
•  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, replace the PCM. (See PCM REMOVAL/INSTALLATION [MZR 2.0 DISI i-stop].)