P0645

P0645-A/C CLUTCH RELAY CIRCUIT







- When Monitored:
With the ignition on. Battery voltage greater than 10.4 volts.

- 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. A/C CLUTCH OPERATION

NOTE: The DTC must not be active for the actuator test to operate properly, clear all DTC before continuing.

1. Ignition on, engine not running.
2. With a scan tool in the Powertrain Actuators, actuate the A/C Clutch

Is the A/C Clutch operating?

Yes

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

No

- Go To 2

2. A/C CLUTCH CONTROL OPERATION FROM THE PCM
1. Turn the ignition off.
2. Disconnect the TIPM C1 harness connector.
3. Turn the ignition on.
4. Using the scan tool in the Powertrain Actuators, actuate the A/C Clutch
5. With a 12-volt test light connected to battery voltage, probe the A/C Clutch Control circuit in the TIPM C1 harness connector.

Does the test light illuminate brightly and flash on and 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.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 3

3. (C28) A/C CLUTCH CONTROL CIRCUIT SHORTED TO BATTERY VOLTAGE




1. Stop the A/C Clutch actuation.
2. Turn the ignition off.
3. Disconnect the PCM C3 harness connector.
4. Turn the ignition on.
5. Measure the voltage of the (C28) A/C Clutch Control circuit at the TIPM C1 harness connector.

Does the voltmeter indicate voltage present?

Yes

- Repair the short to voltage in the (C28) A/C Clutch Relay Control circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 4

4. (C28) 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 (C28) A/C Clutch Control circuit from the TIPM harness connector to the appropriate terminal of special tool #8815.

Is the resistance below 5.0 ohms?

Yes

- Go To 5

No

- Repair the open in the (C28) A/C Clutch Control circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

5. (C28) A/C CLUTCH CONTROL CIRCUIT SHORTED TO GROUND




1. Measure the resistance between ground and the (C28) A/C Clutch Control circuit in the TIPM C1 harness connector.

Is the resistance below 100 ohms?

Yes

- Repair the short to ground in the (C28) A/C Clutch Control circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 6

6. PCM

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

1. Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.

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