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A/C Signal Circuit Troubleshooting (K20C2)

  1. DTC check

    -1. Turn the vehicle to the ON mode.

    -2. Check for Pending or Confirmed DTCs with the HDS.

    DTC Description Confirmed DTC Pending DTC
         

    Are any Pending or Confirmed DTCs indicated?

    YES 

    Go to the indicated DTC's troubleshooting.

    NO 

    Go to step 2.

  2. A/C compressor clutch condition check

    -1. Start the engine, and let it idle.

    -2. Turn the blower switch on.

    -3. Turn the A/C switch on.

    -4. Check the parameter (s) below with the HDS.

    Signal Threshold Current conditions
    Values Unit Values Unit
    A/C CLUTCH ON      

    Do the current condition (s) match the threshold?

    YES 

    Go to step 3.

    NO 

    Do the A/C system test .

  3. A/C system check

    -1. Check the A/C system .

    Does the A/C system operate?

    YES 

    The A/C signal circuit is OK.

    NO 

    Go to step 4.

  4. A/C compressor clutch circuit check

    -1. Turn the vehicle to the OFF (LOCK) mode.

    -2. Turn the vehicle to the ON mode.

    -3. Activate the A/C CLUTCH in the INSPECTION MENU with the HDS.

    A/C CLUTCH

    Is there a clicking noise from the A/C compressor clutch?

    YES 

    The A/C compressor clutch circuit is OK. Do the A/C system test .

    NO 

    Go to step 5.

  5. Open wire check (ACC/ A/C MG CLUTCH RLY CL- line)

    -1. Turn the vehicle to the OFF (LOCK) mode.

    -2. Jump the SCS line with the HDS, and wait more than 1 minute.

    -3. Disconnect the following connector.

    PCM connector E (80P)

    -4. Turn the vehicle to the ON mode.

    -5. Connect terminals A and B with a jumper wire.

    Terminal A PCM connector E (80P) No. 31
    Terminal B Body ground

    Is there a clicking noise from the A/C compressor clutch?

    YES 

    The ACC/ A/C MG CLUTCH RLY CL- wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM , then recheck. If the symptom/indication goes away and the PCM was substituted, replace the original PCM .

    NO 

    Check for poor connections or loose terminals at the A/C compressor clutch relay and the PCM. If the connections and terminals are OK, check the A/C compressor clutch relay. If needed, repair an open in the ACC/ A/C MG CLUTCH RLY CL- wire between the PCM (E31) and the A/C compressor clutch relay, or other parts in the A/C systems.