P0645-A/C CLUTCH CONTROL CIRCUIT
For a complete wiring diagram Refer to Section 8W.
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When Monitored:
With the ignition on. Battery voltage greater than 10 volts. A/C Switch on.
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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.
Possible Causes
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(C13) A/C CLUTCH CONTROL CIRCUIT SHORTED TO BATTERY VOLTAGE
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(C13) A/C CLUTCH CONTROL CIRCUIT OPEN
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(C13) A/C CLUTCH CONTROL CIRCUIT SHORTED TO GROUND
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TIPM
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PCM
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Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.
(Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
Diagnostic Test
1.
A/C CLUTCH OPERATION
Ignition on, engine not running.
With a scan tool, actuate the A/C Clutch.
Is the A/C Clutch actuating?
Yes
No
2.
(C13) A/C CLUTCH CONTROL CIRCUIT SHORTED TO VOLTAGE
Stop the A/C Clutch actuation.
Turn the ignition off.
Disconnect the C3 PCM harness connector.
Disconnect the C1 TIPM harness connector.
Ignition on, engine not running.
Measure the voltage on the (C13) A/C Clutch Control circuit at the C1 TIPM harness connector.
Does the voltmeter indicate voltage present?
Yes
No
3.
(C13) A/C CLUTCH CONTROL CIRCUIT OPEN
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 Miller
Special Tool #8815 to perform diagnosis.
Measure the resistance of the (C13) A/C Clutch Control circuit from the C1 TIPM harness connector to the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?
Yes
No
4.
(C13) A/C CLUTCH CONTROL CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the (C13) A/C Clutch Control circuit at the C1 TIPM harness connector.
Is the resistance below 5.0 ohms?
Yes
No
5.
A/C CLUTCH CONTROL OPERATION FROM THE PCM
Turn the ignition off.
Connect the C3 PCM harness connector.
Ignition on, engine not running.
Using the scan tool in the PCM, actuate the A/C Clutch.
With a 12-volt test light connected to ground, probe the (C13) A/C Clutch Control circuit in the C1 TIPM harness connector.
Does the test light illuminate brightly and flash on an off?
Yes
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NOTE:
Before continuing, check the TIPM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
If OK, replace the TIPM in accordance with the Service Information.
No
6.
PCM
NOTE:
Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
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
No