P0647-A/C CLUTCH CONTROL CIRCUIT HIGH

For a complete wiring diagram Refer to Section 8W

When Monitored:
With the ignition on and the A/C Compressor command on.
Set Condition:
The ECM detects a short circuit on the (C27) A/C Compressor Control circuit for 0.48 seconds.

Possible Causes

INTERMITTENT DTC

(C27) A/C COMPRESSOR CONTROL CIRCUIT SHORTED TO VOLTAGE

(C27) A/C COMPRESSOR CONTROL CIRCUIT SHORTED TO THE (K343) FUSED MAIN RELAY OUTPUT CIRCUIT

(C27) A/C COMPRESSOR CONTROL CIRCUIT OPEN OR HIGH RESISTANCE

A/C COMPRESSOR

ENGINE CONTROL MODULE (ECM)

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

1.DTC IS ACTIVE

Is the status Active for this DTC?

Yes

Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

2.(C27) A/C COMPRESSOR CONTROL CIRCUIT SHORTED TO VOLTAGE

Is there any voltage present?

Yes

Repair the (C27) A/C Compressor Control circuit for a short to voltage.
Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

3.(C27) A/C COMPRESSOR CONTROL CIRCUIT SHORTED TO THE (K343) FUSED MAIN RELAY OUTPUT CIRCUIT

Is the resistance above 10.0 ohms?

Yes

Repair the (C27) A/C Compressor Control circuit for a short to the (K343) Fused Main Relay Output circuit.
Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

4.(C27) A/C COMPRESSOR CONTROL CIRCUIT OPEN OR HIGH RESISTANCE

Is the resistance below 10.0 ohms?

Yes

Repair the (C27) A/C Compressor Control circuit for an open circuit or high resistance.
Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

5.A/C COMPRESSOR

Is the status Active for this DTC?

Yes

Replace the A/C Compressor in accordance with the Service Information.
Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

6.ENGINE CONTROL MODULE (ECM)

Were any problems found?

Yes

Repair as necessary.
Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

Replace the Engine Control Module (ECM) in accordance with the Service Information.
Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)