P0645

P0645-A/C CLUTCH CONTROL CIRCUIT







- 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. Pre-Diagnostic Troubleshooting Procedure.

1. ACTIVE DTC
1. Start the engine.
2. Allow the engine to reach normal operating temperature.
3. Turn the A/C on.
4. With the scan tool, select View DTCs.

Is the DTC Active at this time?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition Test

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




1. Turn the ignition off.
2. Disconnect the C3 PCM harness connector.
3. Disconnect the C1 TIPM harness connector.
4. Ignition on, engine not running.
5. 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




1. 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 PCM Pinout Box 8815 to perform diagnosis.

2. Measure the resistance of the (C13) A/C Clutch Control circuit from the C1 TIPM harness connector to the appropriate terminal of PCM Pinout Box 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




1. 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




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

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.

No

- Go To 6

6. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the related A/C Clutch and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched or partially broken wires.
3. 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.
4. 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