DTC Troubleshooting: P0647 (128-7)

DTC P0647:  A/C Clutch Relay Circuit Shorted to Power

1.Turn the ignition switch ON (II).

2.Clear the DTC with the HDS.

3.Do the A/C CLUTCH ON/OFF in the INSPECTION MENU with the HDS.

4.Check for Temporary DTCs or DTCs with the HDS.

Is DTC P0647 indicated?


YES - Go to 5.


NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the A/C clutch relay and the ECM.n


5.Turn the ignition switch OFF, and wait 30 seconds.

6.Disconnect the A/C clutch relay in the under-hood fuse/relay box.

7.Disconnect ECM connector No. 2 (58P).

8.Measure voltage between ECM connector No. 2 terminal No. 45 and body ground.

 

Is there battery voltage?


YES - Repair short to power in the wire between the A/C clutch relay and ECM connector No. 2 terminal No. 45, then go to 9.


NO - Go to 14.

9.Reconnect all connectors.

10.Turn the ignition switch ON (II).

11.Reset the ECM with the HDS.

12.Do the A/C CLUTCH ON/OFF in the INSPECTION MENU with the HDS.

13.Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?


YES - If DTC P0647 is indicated, check for poor connections or loose terminals at the A/C clutch relay and the ECM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.


NO - Troubleshooting is complete.n


14.Update the ECM if it does not have the latest software, or substitute a known-good ECM.

15.Do the A/C CLUTCH ON/OFF in the INSPECTION MENU with the HDS.

16.Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?


YES - If DTC P0647 is indicated, check for poor connections or loose terminals at the A/C clutch relay and the ECM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.


NO - If the ECM was updated, troubleshooting is complete. If the ECM was substituted, replace the original ECM.n