DTC Troubleshooting

DTC P2647: Rocker Arm Oil Pressure Switch Circuit High Voltage

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 engine oil level OK?

YES - Go to step 2.

NO - Adjust the engine oil to the proper level, then go to step 14.

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

Is the result OK?

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

NO - Go to step 5.

5. Check the result of step 4.
- Rocker Arm Oil Pressure Switch Failure
- Rocker Arm Oil Pressure Switch Open
- Rocker Arm Oil Pressure Switch SIG Line Open
- Rocker Arm Oil Pressure Switch GND Line Open

Is the test result any of the 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 14.

6. Turn the ignition switch OFF.
7. Disconnect the rocker arm oil pressure switch 2P connector.




8. At the switch side, check for continuity between rocker arm oil pressure switch 2P connector terminals No. 1 and No. 2.

Is there continuity?

YES - Go to step 9.

NO - Replace the rocker arm oil pressure switch, then go to step 13.

9. Turn the ignition switch 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 13.

NO - Go to step 11.




11. Measure voltage between ECM/PCM connector terminal B11 and body ground.

Is there battery voltage?

YES - Repair open in the wire between the ECM/PCM (B11) and the rocker arm oil pressure switch, then go to step 12.

NO - Go to step 19.

12. Turn the ignition switch OFF.
13. Reconnect the rocker arm oil pressure switch 2P connector.
14. Turn the ignition switch ON (II).
15. Reset the ECM/PCM with the HDS.
16. Do the ECM/PCM idle learn procedure.
17. 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 and the ECM/PCM, then go to step 1.

NO - If Temporary DTC or DTC P2647 is not indicated, or if any other Temporary DTCs or DTCs are indicated, go to step 18.

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

Does the screen indicate PASSED?

YES - If there was no Temporary DTCs or DTCs indicated on step 17, troubleshooting is complete. If any other Temporary DTCs or DTCs was indicated on step 17, go to the indicated DTC's troubleshooting.

NO - If the screen indicates FAILED, go to step 1 and recheck. If the screen indicates NOT COMPLETED, go to step 16 and recheck.

19. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM.
20. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, then let it idle.
21. 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 and the ECM/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM, then go to step 20. If the ECM/PCM was substituted, go to step 1.

NO - If Temporary DTC or DTC P2647 is not indicated, or if any other Temporary DTCs or DTCs are indicated, go to step 22.

22. 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 was indicated on step 21, go to the indicated DTC's 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 20. If the ECM/PCM was substituted, go to step 1. If the screen indicates NOT COMPLETED, go to step 20 and recheck.