Except PZEV Models

DTC P2647: Rocker Arm Oil Pressure Switch Circuit High Voltage (All models except PZEV)

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.

1. Check the engine oil level.

Is the level OK?

YES - Go to step 2.

NO - Adjust the engine oil to the proper level, then go to step 17.

2. Turn the ignition switch to ON (II).
3. Clear the DTC with the HDS.
4. Do the VTEC TEST in the INSPECTION MENU with the HDS.

NOTE: If DTC stored during VTEC TEST, check for DTCs MENU. If DTC P2647 indicated, go to step 6. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTCs troubleshooting.

Is the result OK?

YES - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the rocker arm oil pressure switch, the rocker arm oil control solenoid, and the ECM/PCM.

NO - Go to step 5.

5. Check the result of step 4.
- VTEC Switch Failure
- VTEC Switch Open
- VTEC Switch SIG Line Open
- VTEC Switch GND Line Open

Is the test result any of those above?

YES - Go to step 6.

NO - Check for poor connections or loose terminals at the rocker arm oil pressure switch. If it is OK, replace the rocker arm oil control valve, then, go to step 15.

6. Turn the ignition switch to LOCK (0).
7. Disconnect the rocker arm oil pressure switch 2P connector.
8. At the rocker arm oil pressure switch side, check for continuity between its 2P connector terminals.






Is there continuity?

YES - Go to step 9.

NO - Replace the rocker arm oil pressure switch, then go to step 16.

9. Turn the ignition switch to ON (II).
10. Measure voltage between rocker arm oil pressure switch 2P connector terminal No. 1 and body ground.






Is there battery voltage?

YES - Repair open in the wire between the rocker arm oil pressure switch and G101, then go to step 15.

NO - Go to step 11.

11. Turn the ignition switch to LOCK (0).
12. Jump the SCS line with the HDS.
13. Disconnect ECM/PCM connector C (49P).
14. Check for continuity between rocker arm oil pressure switch 2P connector terminal No. 1 and ECM/PCM connector terminal C22.






Is there continuity?

YES - Go to step 22.

NO - Repair open in the wire between the ECM/PCM (C22) and the rocker arm oil pressure switch, then go to step 22.

15. Turn the ignition switch to LOCK (0).
16. Reconnect all connectors.
17. Turn the ignition switch to ON (II).
18. Reset the ECM/PCM with the HDS.
19. Do the ECM/PCM idle learn procedure. Programming and Relearning
20. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P2647 indicated?

YES - Check for poor connections or loose terminals at the rocker arm oil pressure switch, the rocker arm oil control solenoid, and the ECM/PCM, then go to step 1.

NO - Go to step 21.

21. Monitor the OBD STATUS for DTC P2647 in the DTCs MENU with the HDS.

Does the screen indicate PASSED?

YES - Troubleshooting is complete. If any other Temporary DTCs or DTCs were indicated in step 20, go to the indicated DTCs troubleshooting.

NO - If the screen indicates FAILED, go to step 1 and recheck. If the screen indicates NOT COMPLETED, keep idling until a result comes on.

22. Reconnect all connectors.
23. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM.
24. Start the engine, and let it idle.
25. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P2647 indicated?

YES - Check for poor connections or loose terminals at the rocker arm oil pressure switch, the rocker arm oil control solenoid, and the ECM/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM, then go to step 24. If the ECM/PCM was substituted, go to step 1.

NO - Go to step 26.

26. Monitor the OBD STATUS for DTC P2647 in the DTCs MENU with the HDS.

Does the screen indicate PASSED?

YES - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM. If any other Temporary DTCs or DTCs were indicated in step 25, go to the indicated DTCs troubleshooting.

NO - If the screen indicates FAILED, check for poor connections or loose terminals at the rocker arm oil pressure switch and the ECM/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM, then go to step 24. If the ECM/PCM was substituted, go to step 1. If the screen indicates NOT COMPLETED, keep idling until a result comes on.