P0646-A/C CLUTCH CONTROL CIRCUIT LOW
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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 Compressor Clutch Control circuit. The PCM grounds this signal to indicate a request for A/C Compressor Clutch operation.
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When Monitored:
With the ignition on and the A/C Clutch command off.
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Set Condition:
The PCM a short to ground on the (C13) A/C Clutch Control circuit for 0.5 second.
Possible Causes |
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| (C13) A/C CLUTCH CONTROL CIRCUIT SHORTED TO GROUND |
| TOTALLY INTEGRATED POWER MODULE |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
| 1. | Ignition on, engine not running. |
| 2. | With the scan tool, erase DTCs in the PCM. |
| 3. | With the scan tool, actuate the A/C Clutch. |
| 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 AN INTERMITTENT DTC diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
2. CHECK THE (C13) A/C CLUTCH CONTROL CIRCUIT FOR A SHORT TO GROUND
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| 1. | Turn the ignition off. |
| 2. | Disconnect the TIPM C1 harness connector. |
| 3. | Disconnect the PCM C2 harness connector. |
| 4. | Measure the resistance between ground and the (C13) A/C Clutch Control circuit at the TIPM C1 harness connector. |
Is the resistance above 10k Ohms?
Yes
- Replace and program the Totally Integrated Power Module in accordance with the service information.
- Perform the BODY VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Totally Integrated Power (TIPM) - Standard Procedure).
No
- Repair the (C13) A/C Clutch Control circuit for a short to ground.
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Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM)
- Standard Procedure).