P0645-A/C CLUTCH RELAY CIRCUIT EXCESSIVE CURRENT

For a complete wiring diagram Refer to Section 8W

When Monitored:
With the ignition on and the ECM A/C Clutch Relay command on.
Set Condition:
The ECM detects excessive current on the A/C Clutch Relay Control circuit for 0.5 second.

Possible Causes

INTERMITTENT CONDITION

A/C CLUTCH RELAY

A/C CLUTCH RELAY CONTROL CIRCUIT SHORTED TO VOLTAGE

ECM

Diagnostic Test

1.A/C CLUTCH RELAY OPERATION

NOTE: If the ECM detects and stores a DTC, the ECM also stores the engine/vehicle operating conditions under which the DTC was set. Some of these conditions are displayed on the scan tool at the same time the DTC is displayed.

NOTE: Before erasing stored DTCs, record these conditions. Attempting to duplicate these conditions may assist when checking for an active DTC.

Is the A/C Clutch Relay clicking?

Yes

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

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2.A/C CLUTCH RELAY

Does the test light cycle on and off?

Yes

Replace the A/C Clutch Relay.
Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

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3.A/C CLUTCH RELAY CONTROL CIRCUIT SHORTED TO VOLTAGE

Is the voltage above 1.0 volt?

Yes

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

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4.ECM

If there are no possible causes remaining, view repair.

Repair

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