P0645

P0645-A/C CLUTCH CONTROL CIRCUIT







- When Monitored:
With the engine running and battery voltage greater than 10.4 volts.

- Set Condition:
The Powertrain Control Module (PCM) detects that the A/C Compressor control circuit voltage is not within an acceptable range.





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 a scan tool, select View DTCs and record any related Freeze Frame data.

Is the DTC Active at this time?

Yes

- Go To 2

No

- Perform the CHECKING FOR AN INTERMITTENT DTC diagnostic procedure. Checking for an Intermittent DTC.

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




1. Turn the ignition off.
2. Disconnect the C3 Powertrain Control Module (PCM) harness connector.
3. Disconnect the C1 Totally Integrated Power Module (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.

Does the voltmeter indicate voltage present?

Yes

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

No

- Go To 5

5. A/C CLUTCH CONTROL OPERATION FROM THE PCM




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 along with the Adapter 8815-1 to perform the diagnosis.

2. Install PCM Pinout Box 8815 and Adapter 8815-1.
3. Ignition on, engine not running.
4. Using the scan tool in the PCM, actuate the A/C Clutch.
5. Measure the voltage between the appropriate terminal of the PCM Pinout Box 8815 and ground.

Is the voltage below 1.0 volt?

Yes

- Go To 6

No

- Go To 7

6. TOTALLY INTEGRATED POWER MODULE (TIPM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Totally Integrated Power Module (TIPM) 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 between connectors.
4. Perform any Technical Service Bulletins (TSBs) that may apply.

Were there any problems found?

Yes

- Repair as necessary.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.

No

- Replace and program the Totally Integrated Power Module (TIPM).
- Perform the BODY VERIFICATION TEST. Body Verification Test.

7. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the 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 between connectors.
4. Search for any Technical Service Bulletins (TSBs) that may apply.

Were there any problems found?

Yes

- Repair as necessary.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.

No

- Replace and program the Powertrain Control Module (PCM).
- Perform the PCM VERIFICATION TEST. PCM Verification Test.