| DTC P0645: | A/C Compressor Clutch Relay Circuit Open |
| 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 P0645 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 compressor clutch relay and the ECM.n |
| 5. | Turn the ignition switch OFF. |
| 6. | Disconnect the A/C compressor clutch relay in the under-hood fuse/relay box. |
| 7. | Turn the ignition switch ON (II). |
| 8. | Measure voltage between A/C compressor clutch relay 4P connector terminal No. 4 and body ground.
Is there battery voltage? YES - Go to 9. NO - Repair open in the wire between the A/C compressor clutch relay and the No. 36 IG2 HAC (A/C) (10 A) fuse in the under-dash fuse/relay box, then go to 14. |
| 9. | Check the A/C compressor clutch relay. Is the A/C compressor clutch relay OK? YES - Go to 10. NO - Replace the A/C compressor clutch relay, then go to 14. |
| 10. | Turn the ignition switch OFF, and wait 1 minute. |
| 11. | Reconnect the A/C compressor clutch relay. |
| 12. | Disconnect ECM connector No. 2 (58P). |
| 13. | Measure voltage between ECM connector No. 2 terminal No. 45 and body ground.
Is there battery voltage? YES - Go to 19. NO - Repair open in the wire between the A/C compressor clutch relay and ECM connector No. 2 terminal No. 45, then go to 14. |
| 14. | Reconnect all connectors. |
| 15. | Turn the ignition switch ON (II). |
| 16. | Reset the ECM with the HDS. |
| 17. | Do the A/C CLUTCH ON/OFF in the INSPECTION MENU with the HDS. |
| 18. | Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P0645 is indicated, check for poor connections or loose terminals at the A/C compressor 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 |
| 19. | Update the ECM if it does not have the latest software, or substitute a known-good ECM. |
| 20. | Do the A/C CLUTCH ON/OFF in the INSPECTION MENU with the HDS. |
| 21. | Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P0645 is indicated, check for poor connections or loose terminals at the A/C compressor 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 |