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Home >> Mazda >> 2016 >> 6 Touring, Automatic Trans >> Repair and Diagnosis >> Engine Performance >> System >> Symptom Troubleshooting - Engine Control System >> No. 24 A/C Is Always On Or A/C Compressor Runs Continuously >> Diagnostic Procedure
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Diagnostic Procedure

STEP INSPECTION RESULTS ACTION
1 VERIFY PCM, INSTRUMENT CLUSTER AND CLIMATE CONTROL UNIT DTC  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 DETERMINE IF MALFUNCTION CAUSE IS MAGNETIC CLUTCH OR OTHER 
  • 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 INSPECT IF MALFUNCTION CAUSE IS MAGNETIC CLUTCH POWER SUPPLY CIRCUIT OR MAGNETIC CLUTCH 
  • 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 INSPECT MAGNETIC CLUTCH CLEARANCE 
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 DETERMINE IF MALFUNCTION CAUSE IS A/C RELAY CONTROL SIGNAL OR A/C REQUEST SIGNAL 
  • 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.
No Go to the next step.
6 INSPECT A/C RELAY 
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.