P0645-A/C CLUTCH RELAY CIRCUIT SHORT TO GROUND
For a complete wiring diagram Refer to Section 8W
- When Monitored:
With the ignition on and the ECM A/C Clutch Relay command off.
- Set Condition:
The ECM does not detect voltage on the A/C Clutch Relay Control circuit for 0.5 second.
| Possible Causes |
| INTERMITTENT CONDITION |
| FUSED ASD RELAY OUTPUT CIRCUIT OPEN |
| A/C CLUTCH RELAY |
| A/C CLUTCH RELAY CONTROL CKT OPEN |
| A/C CLUTCH RELAY CONTROL CIRCUIT SHORT TO GROUND |
| ECM |
Diagnostic Test
1. A/C CLUTCH RELAY OPERATIONNOTE: 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.
Turn the ignition on.
With the scan tool, actuate the A/C Clutch Relay.
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)
No
- Go To2
2. FUSED ASD RELAY OUTPUT CIRCUIT OPEN
Turn the ignition off.
Remove the A/C Clutch Relay from the PDC.
Turn the ignition on.
Using a 12-volt test light connected to ground, probe the Fused ASD Relay Output circuit in the PDC.
Does the test light illuminate?
Yes
- Go To3
No
- Repair the Fused ASD Relay Output circuit for an open.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
3. A/C CLUTCH RELAY
Using a 12-volt test light connected to 12-volts, probe the A/C Clutch Relay Control circuit in the PDC.
With the scan tool, actuate the 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).
No
- Go To4
4. A/C CLUTCH RELAY CONTROL CIRCUIT OPEN
Turn the ignition off.
Disconnect the ECM harness connector.
Measure the resistance of the A/C Clutch Relay Control circuit.
Is the resistance below 10.0 ohms?
Yes
- Go To5
No
- Repair the A/C Clutch Relay Control circuit for an open.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
5. A/C CLUTCH RELAY CONTROL CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the A/C Clutch Relay Control circuit.
Is the resistance below 1000 ohms?
Yes
- Repair the A/C Clutch Relay Control circuit for a short to ground.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
No
- Go To6
6. 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).