DTC Troubleshooting
DTC Troubleshooting: P2647
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 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 17.
2. Turn the ignition switch to ON (II).
3. Clear the DTC with the HDS.
4. Check the rocker arm oil pressure switch in the DATA LIST with the HDS.
Does the HDS indicate OFF?
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 pressure switch and the ECM.
5. Turn the ignition switch to LOCK (0).
6. Disconnect the rocker arm oil pressure switch 2P connector.
7. Connect rocker arm oil pressure switch 2P connector terminals No. 1 and No. 2 with a jumper wire.
8. Turn the ignition switch to ON (II).
9. Check the rocker arm oil pressure switch in the DATA LIST with the HDS.
Does the HDS indicate ON?
YES -
Replace the rocker arm oil pressure switch Rocker Arm Oil Pressure Switch Removal/Installation, then go to step 16.
NO -
Go to step 10.
10. Turn the ignition switch to LOCK (0).
11. Remove the jumper wire from the rocker arm oil pressure switch.
12. Jump the SCS line with the HDS.
13. Disconnect ECM connector B (49P).
14. Check for continuity between ECM connector terminal B20 and rocker arm oil pressure switch 2P connector terminal No. 1.
Is there continuity?
YES -
Go to step 15.
NO -
Repair an open in the wire between the ECM (B20) and the rocker arm oil pressure switch, then go to step 16.
15. Check for continuity between the rocker arm oil pressure switch 2P connector terminal No. 2 and body ground.
Is there continuity?
YES -
Go to step 22.
NO -
Repair an open in the wire between the rocker arm oil pressure switch and G101; M/T, A/T, then go to step 16.
16. Reconnect all connectors.
17. Turn the ignition switch to ON (II).
18. Reset the ECM with the HDS.
19. Do the ECM idle learn procedure ECM/PCM Idle Learn Procedure.
20. Check for Pending or Confirmed 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, 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 HDS indicate PASSED?
YES -
Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 20, go to the indicated DTC's troubleshooting.
NO -
If the HDS indicates FAILED, check for poor connections or loose terminals at the rocker arm oil pressure switch and the ECM, then go to step 1. If the HDS indicates NOT COMPLETED, keep idling until a result comes on.
22. Reconnect all connectors.
23. Update the ECM if it does not have the latest software ECM/PCM Update, or substitute a known-good ECM.
24. Start the engine, and let it idle.
25. Check for Pending or Confirmed 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. If the ECM was updated, substitute a known-good ECM, then go to step 24. If the ECM 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 HDS 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 Pending or Confirmed DTCs were indicated in step 25, go to the indicated DTC's troubleshooting.
NO -
If the HDS indicates FAILED, check for poor connections or loose terminals at the rocker arm oil pressure switch and the ECM. If the ECM was updated, substitute a known-good ECM, then go to step 24. If the ECM was substituted, go to step 1. If the HDS indicates NOT COMPLETED, keep idling until a result comes on.