DTC Troubleshooting

DTC Troubleshooting: P2647

DTC P2647: Rocker Arm Oil Pressure Switch (VTEC 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. Initial Inspection and Diagnostic Overview

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 to 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, the system is OK at this time. Check for poor connections or loose terminals at the rocker arm oil pressure switch (VTEC oil pressure switch) and the ECM.

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 the above?
YES - Go to step 6.

NO - Check for poor connections or loose terminals at the rocker arm oil pressure switch (VTEC oil pressure switch). If it is OK, replace the rocker arm oil control valve (VTEC solenoid valve), Service and Repair then go to step 14.


6. Turn the ignition switch to LOCK (0).

7. Disconnect the rocker arm oil pressure switch (VTEC oil pressure switch) 2P connector.

8. At the rocker arm oil pressure switch (VTEC oil pressure switch) side, check for continuity between rocker arm oil pressure switch (VTEC 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 (VTEC oil pressure switch), Service and Repair then go to step 13.






9. Turn the ignition switch to ON (II).

10. Measure the voltage between rocker arm oil pressure switch (VTEC 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 (VTEC oil pressure switch) and G101, then go to step 12.

NO - Go to step 11.






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

Is there battery voltage?
YES - Repair open in the wire between the ECM (B11) and the rocker arm oil pressure switch (VTEC oil pressure switch), then go to step 12.

NO - Go to step 19.






12. Turn the ignition switch to LOCK (0).

13. Reconnect the rocker arm oil pressure switch (VTEC oil pressure switch) 2P connector.

14. Turn the ignition switch to ON (II).

15. Reset the ECM with the HDS.

16. Do the ECM idle learn procedure. ECM 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 (VTEC oil pressure switch) and the ECM, then go to step 1.

NO - 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 - Troubleshooting is complete. If any other Temporary DTCs or DTCs were indicated in step 17, 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 (VTEC oil pressure switch) and the ECM, then go to step 1. If the screen indicates NOT COMPLETED, go to step 16 and recheck.


19. Turn the ignition switch to LOCK (0).

20. Reconnect all connectors.

21. Update the ECM if it does not have the latest software, ECM Update or substitute a known-good ECM. Initial Inspection and Diagnostic Overview

22. Start the engine, and let it idle.

23. 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 (VTEC oil pressure switch) and the ECM. If the ECM was updated, substitute a known-good ECM, Initial Inspection and Diagnostic Overview then go to step 22. If the ECM was substituted, go to step 1.

NO - Go to step 24.


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

Does the screen indicate PASSED?
YES - If the ECM was updated, troubleshooting is complete. If the ECM was substituted, replace the original ECM. Service and Repair If any other Temporary DTCs or DTCs were indicated in step 22, 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 (VTEC oil pressure switch) and the ECM. If the ECM was updated, substitute a known-good ECM, Initial Inspection and Diagnostic Overview then go to step 22. If the ECM was substituted, go to step 1. If the screen indicates NOT COMPLETED, keep idling until a result comes on.