P0646

P0646-A/C CLUTCH CONTROL CIRCUIT 2 LOW





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

- When Monitored:
With the ignition on.

Battery voltage greater than 10 volts.

A/C Switch on.

- Set Condition:
A 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 a 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. CHECK THE (C3) A/C CLUTCH CONTROL OUTPUT CIRCUIT FOR A SHORT TO GROUND




1. Turn the ignition off
2. Disconnect the TIPM C2 harness connector.
3. Disconnect the A/C Compressor Clutch harness connector.
4. Measure the resistance between ground and the (C3) A/C Clutch Control Output circuit at the A/C Compressor Clutch harness connector.

Is the resistance below 100 Ohms?

Yes

- Repair the short to ground in the (C3) A/C Clutch Control Output circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 3

3. CHECK THE A/C COMPRESSOR CLUTCH FOR CORRECT OPERATION




1. Connect the TIPM C2 harness connector.
2. Ignition on, engine not running.
3. Using a 12-volt test light connected to ground, check the (C3) A/C Clutch Control Output circuit at the A/C Compressor Clutch harness connector.
4. With the scan tool, actuate the A/C Clutch.

Does the test light illuminate brightly?

Yes

- Replace the A/C Compressor Clutch.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 4

4. TOTALLY INTEGRATED POWER MODULE (TIPM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the A/C Clutch, 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 A/C Clutch, TIPM, and Powertrain Control Module connectors.
4. Perform any Technical Service Bulletins that may apply.

Were there any problems found?

Yes

- Repair as necessary.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Replace the Totally Integrated Power Module.
- Perform the BODY VERIFICATION TEST. Body Verification Test.