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 terminal D and magnetic clutch terminal A

• 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 2AF

Item (definition)

Unit/Condition

Definition

Condition/Specification (Reference)

ACCS

Off/On

A/C relay

• A/C relay is off: Off

• A/C relay is on: On

STEP

INSPECTION

RESULTS

ACTION

1

• Retrieve the PCM, instrument cluster and climate control unit DTCs using the M-MDS.

  (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.5].)

  (See DTC INSPECTION [INSTRUMENT CLUSTER].)

  (See DTC DISPLAY [FULL-AUTO AIR CONDITIONER].)

  (See DTC DISPLAY [MANUAL AIR CONDITIONER].)

• Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [SKYACTIV-G 2.5].)

(See DTC TABLE [INSTRUMENT CLUSTER].)

(See DTC TABLE [FULL-AUTO AIR CONDITIONER].)

(See DTC TABLE [MANUAL 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

• A/C relay is removed.

• Switch the ignition 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.

• Refer to the wiring diagram and verify whether or not there is a common connector between magnetic clutch terminal A and A/C relay terminal D.

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has a short to power supply.

No

Go to the next step.

4

• Verify the magnetic clutch clearance.

  (See MAGNETIC CLUTCH ADJUSTMENT [MANUAL AIR CONDITIONER].)

  (See MAGNETIC CLUTCH ADJUSTMENT [FULL-AUTO AIR CONDITIONER].)

• Is the magnetic clutch clearance normal?

Yes

Inspect the magnetic clutch to see if it is stuck.

(See MAGNETIC CLUTCH INSPECTION [MANUAL AIR CONDITIONER].)

(See MAGNETIC CLUTCH INSPECTION [FULL-AUTO AIR CONDITIONER].)

Replace the magnetic clutch if necessary.

(See MAGNETIC CLUTCH DISASSEMBLY/ASSEMBLY [MANUAL AIR CONDITIONER].)

(See MAGNETIC CLUTCH DISASSEMBLY/ASSEMBLY [FULL-AUTO AIR CONDITIONER].)

No

Adjust the magnetic clutch clearance.

(See MAGNETIC CLUTCH ADJUSTMENT [MANUAL AIR CONDITIONER].)

(See MAGNETIC CLUTCH ADJUSTMENT [FULL-AUTO AIR CONDITIONER].)

5

• Access the PCM PID ACCS using the M-MDS.

  (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.5].)

• Monitor the PID ACCS while turning on and off the air conditioner using the switch on the control panel.

• Is the ACCS PID value always ON?

Yes

Climate control unit always transmits A/C request signal.

• Replace the climate control unit.

  (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER].)

  (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].)

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 2AF.

• Refer to the wiring diagram and verify whether or not there is a common connector between A/C relay terminal E and PCM terminal 2AF.

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has a short to ground.

7

Verify the test results.

• If normal, return to the diagnostic index to service any additional symptoms.

  (See SYMPTOM DIAGNOSTIC INDEX [SKYACTIV-G 2.5].)

• If the malfunction remains, inspect the related Service Bulletins and/or On-line Repair 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, reprogram the PCM if a later calibration is available. Retest.