Variable Cylinder Management (VCM) System

DTC 2648: 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.
4. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P2648 indicated?

YES - Go to step 5.

NO - 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.

5. Turn the ignition switch OFF.
6. Disconnect the rocker arm oil control solenoid (VTEC solenoid valve) 2P connector.
7. At the solenoid side, measure resistance between rocker arm oil control solenoid (VTEC solenoid valve) 2P connector terminals No. 1 and No. 2.






Is there 14 - 30 Ohms?

YES - Go to stop 8.

NO - Go to stop 11.

8. Jump the SCS line with the HDS.
9. Disconnect PCM connector C (44P).
10. Check for continuity between PCM connector terminal C24 and body ground.






Is there continuity?

YES - Repair short in the wire between the rocker arm oil control solenoid (VTEC solenoid valve), and the PCM (C24), then go to step 12.

NO - Go to step 19.

11. Replace the rocker arm oil control solenoid (VTEC solenoid valve).
12. Reconnect all connectors.
13. Turn the ignition switch ON (II).
14. Reset the PCM with the HDS.
15. Do the PCM idle learn procedure.
16. Do the VTEC TEST in the INSPECTION MENU with the HDS.
17. 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 18.

18. 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 17, go to the indicated DTCs 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, go to step 16.

19. Reconnect all connectors.
20. Update the PCM if it does not have the latest software, or substitute a known-good PCM.
21. Do the VTEC TEST in the INSPECTION MENU with the HDS.
22. 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 go to step 21. If the PCM was substituted, go to step 1.

NO - Go to step 23.

23. 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 22, go to the indicated DTCs 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, go to step 21.