P0645

P0645-A/C CLUTCH RELAY CIRCUIT

For a complete wiring diagram, refer to the Wiring Information.

Theory of operation

When the ignition switch is on, the Totally Integrated Power Module (TIPM) sends a 12 Volt signal to the Powertrain Control Module (PCM) on the A/C Clutch Relay Control circuit. The PCM grounds this signal to indicate a request for A/C Compressor Clutch operation.

- When Monitored:
With the ignition on. Battery voltage greater than 10.0 Volts. A/C is being requested.

- Set Condition:
An open or shorted condition is detected in the A/C Clutch Relay 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. DTC IS ACTIVE

NOTE: If there are any ASD Relay or system voltage DTCs present, diagnose those DTCs before proceeding with this test procedure.

1. Ignition on, engine not running.
2. With the scan tool, select View DTCs. Copy DTC and Freeze Frame information and clear DTCs.

NOTE: Active or pending DTCs may not allow A/C clutch actuation, make sure all DTCs are cleared before proceeding with this test procedure.

3. With the scan tool, actuate the A/C Compressor.
4. Monitor the scan tool for at least two minutes.
5. With the scan tool, select View DTCs.

Is the status Active for this DTC?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test.

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




1. Turn the ignition off.
2. Disconnect the TIPM C1 harness connector.
3. Disconnect the PCM C1 harness connector.
4. Measure the resistance between ground and the (C13) A/C Clutch Relay Control circuit in the PCM C1 harness connector.

Is the resistance below 100 Ohms?

Yes

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

No

- Go To 3

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




1. Measure the resistance of the (C13) A/C Clutch Control circuit between the TIPM C1 harness connector and the PCM C1 harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 4

No

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

4. TOTALLY INTEGRATED POWER MODULE (TIPM) ACTUATION
1. Reconnect the TIPM C1 harness connector.
2. Turn the ignition on.
3. Connect a jumper between ground and the (C13) A/C Clutch Relay Control circuit at the PCM C1 harness connector.

NOTE: The A/C Compressor Clutch should engage when the (C13) A/C Clutch Relay Control circuit is jumped to ground.

Did the A/C Compressor Clutch engage when the (C13) A/C Clutch Relay Control circuit is jumped to ground?

Yes

- Go To 6

No

- Go To 5

5. 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 in the related connectors.
4. Perform any Technical Service Bulletins that may apply.

Were any problems found?

Yes

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

No

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

6. POWERTRAIN CONTROL MODULE (PCM)
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 in the related connectors.
4. Perform any Technical Service Bulletins that may apply.

Were any problems found?

Yes

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

No

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