P0645

P0645-A/C CLUTCH RELAY CIRCUIT

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





- When Monitored:
With the ignition on. A/C Compressor is off.

- Set Condition:
The Powertrain Control Module (PCM) detects an open circuit in the A/C Clutch Relay control circuit. One Trip Fault.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

Diagnostic Test

1. DTC IS ACTIVE

NOTE: If there are any ASD/Main 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 Relay actuation, make sure all DTCs are cleared before proceeding with this test procedure.

3. With the scan tool actuate the A/C Relay, cycling between on and off.
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. A/C CLUTCH RELAY
1. Turn the ignition off.
2. Install a known good relay.
3. With the scan tool actuate the A/C Relay, cycling between on and off.
4. Monitor the scan tool for at least two minutes.
5. With the scan tool, select View DTCs.

Is the DTC active at this time?

Yes

- Go To 3

No

- Replace the A/C Clutch Relay.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

3. CHECK THE (C13) A/C CLUTCH CONTROL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Remove the A/C Clutch Relay.
3. Disconnect the PCM C1 harness connector.
4. Measure the resistance of the (C13) A/C Clutch Control circuit between the PCM C1 harness connector and the A/C Clutch Relay terminal.

Is the resistance below 5.0 Ohms?

Yes

- Go To 4

No

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

4. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Relay 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). .
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.