DTC Troubleshooting

DTC P2648: Rocker Arm Oil Control Solenoid (VTEC Solenoid Valve) Circuit Low Voltage

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

1. Turn the ignition switch ON (II).
2. Clear the DTC with the HDS.
3. 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 control solenoid (VTEC solenoid valve) and the PCM.

NO - Go to step 4.

4. Turn the ignition switch OFF.
5. Disconnect the rocker arm oil control solenoid (VTEC solenoid valve) 1P connector.




6. Measure resistance between the rocker arm oil control solenoid (VTEC solenoid valve) 1P connector terminal and the solenoid valve body.

Is there 14-30 ohms at room temperature?

YES - Go to step 7.

NO - Go to step 10.

7. Jump the SCS line with the HDS.
8. Disconnect PCM connector A (31P).




9. Check for continuity between PCM connector terminal A22 and body ground.

Is there continuity?

YES - Repair short in the wire between the PCM (A22) and the rocker arm oil control solenoid (VTEC solenoid valve), then Go to step 11.

NO - Go to step 18.

10. Replace the rocker arm oil control solenoid (VTEC solenoid valve).
11. Reconnect all connectors.
12. Turn the ignition switch ON (II).
13. Reset the PCM with the HDS.
14. Do the PCM idle learn procedure.
15. Do the VTEC TEST in the INSPECTION MENU with the HDS.
16. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P2648 indicated?

YES - Check for poor connections or loose terminals at the rocker arm oil control solenoid (VTEC solenoid valve) and the PCM, then Go to step 1.

NO - Go to step 17.

17. Monitor the OBD STATUS for DTC P2648 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 16, 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 control solenoid (VTEC solenoid valve) and the PCM, then Go to step 1. If the screen indicates NOT COMPLETED, keep idling until a result comes on.

18. Update the PCM if it does not have the latest software, or substitute a known good PCM.
19. Do the VTEC TEST in the INSPECTION MENU with the HDS.
20. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P2648 indicated?

YES - Check for poor connections or loose terminals at the rocker arm oil control solenoid (VTEC solenoid valve) and the PCM. If the PCM was updated, substitute a known good PCM, then recheck. If the PCM was substituted, Go to step 1.

NO - Go to step 21.

21. Monitor the OBD STATUS for DTC P2648 in the DTCs MENU with the HDS.

Does the screen indicate PASSED?

YES - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM. If any other Temporary DTCs or DTCs were indicated in step 20, 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 control solenoid (VTEC solenoid valve) and the PCM. If the PCM was updated, substitute a known good PCM, then recheck. If the PCM was substituted, Go to step 1. If the screen indicates NOT COMPLETED, keep idling until a result comes on.