P0645

P0645-A/C CLUTCH CONTROL CIRCUIT





For a complete wiring diagram Consult Diagrams/Electrical.

- 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.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Initial Inspection and Diagnostic Overview.

Diagnostic Test

1. ACTIVE DTC
Turn the ignition on.
With the scan tool, Clear DTCs in the Powertrain Control Module (PCM).
With the scan tool, actuate the A/C Compressor Clutch Relay Control State.
With the scan tool, select View DTCs.
Is the DTC Active at this time?

Yes

- Go To 2

No

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition.

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




Stop the A/C Clutch actuation.
Turn the ignition off.
Disconnect the C3 PCM harness connector.
Disconnect the C1 TIPM harness connector.
Ignition on, engine not running.
Measure the voltage on the (C13) A/C Clutch Control circuit at the C1 TIPM harness connector.
Is there any voltage present?

Yes

- Repair the short to voltage in the (C13) A/C Clutch Control circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Go To 3

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




Turn the ignition off.

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.

Measure the resistance of the (C13) A/C Clutch Control circuit from the C1 TIPM harness connector to the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?

Yes

- Go To 4

No

- Repair the open in the (C13) A/C Clutch Control circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

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




Measure the resistance between ground and the (C13) A/C Clutch Control circuit at the C1 TIPM harness connector.
Is the resistance below 5.0 ohms?

Yes

- Repair the short to ground in the (C13) A/C Clutch Control circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Go To 5

5. A/C CLUTCH CONTROL OPERATION FROM THE PCM




Turn the ignition off.
Connect the C3 PCM harness connector.
Ignition on, engine not running.
Using the scan tool in the PCM, actuate the A/C Clutch.
With a 12-volt test light connected to ground, probe the (C13) A/C Clutch Control circuit in the C1 TIPM harness connector.

NOTE: The test light should be illuminated and bright proportional to the maximum duty cycle allowed by the scan tool. For example, if the scan tool allows 100% actuation, the brightness should be as bright as a direct connection to the battery. If the scan tool allows a maximum 25% actuation, the brightness should be 25% as bright as a direct connection to the battery.

Does the test light illuminate accordingly during the actuation?

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.

No

- Go To 6

6. POWERTRAIN CONTROL MODULE (PCM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the A/C Clutch and the Powertrain Control Module (PCM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the A/C Clutch and Control Module connectors.
Search for any Technical Service Bulletins that may apply.
Were there any problems found?

Yes

- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Replace and program the Powertrain Control Module.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.