P0645-A/C CLUTCH CONTROL CIRCUIT





For a complete wiring diagram Refer to Section 8W.


  • When Monitored:

    With the ignition on. Battery voltage greater than 10 volts. A/C Switch on.

  • Set Condition:

    An open or shorted condition is detected in the A/C clutch control circuit. One Trip Fault. Three good trips to turn off the MIL.


Possible Causes
  
(C13) A/C CLUTCH CONTROL CIRCUIT SHORTED TO BATTERY VOLTAGE
  
(C13) A/C CLUTCH CONTROL CIRCUIT OPEN
  
(C13) A/C CLUTCH CONTROL CIRCUIT SHORTED TO GROUND
  
TIPM
  
PCM
  

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).



Diagnostic Test

1.A/C CLUTCH OPERATION




Is the A/C Clutch actuating?

Yes


No
  • Go To 2

2.(C13) A/C CLUTCH CONTROL CIRCUIT SHORTED TO VOLTAGE










Does the voltmeter indicate voltage present?

Yes


No
  • Go To 3

3.(C13) A/C CLUTCH CONTROL CIRCUIT OPEN




CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.




Is the resistance below 5.0 ohms?

Yes
  • Go To 4


No

4.(C13) A/C CLUTCH CONTROL CIRCUIT SHORTED TO GROUND





Is the resistance below 5.0 ohms?

Yes


No
  • Go To 5

5.A/C CLUTCH CONTROL OPERATION FROM THE PCM









Does the test light illuminate brightly and flash on an off?

Yes

  • NOTE: Before continuing, check the TIPM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

    If OK, replace the TIPM in accordance with the Service Information.


No
  • Go To 6

6.PCM

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.




Were there any problems found?

Yes


No