DTC Troubleshooting
DTC P2646: Rocker Arm Oil Pressure Switch Circuit Low VoltageSpecial Tools Required
- Pressure gauge adapter 07NAJ-P07010A
- A/T low pressure gauge w/panel 07406-0070301
- A/T pressure hose 07406-0020201
- A/T pressure hose, 2,210 mm 07MAJ-PY4011A
- A/T pressure adapter 07MAJ-PY40120
- Oil pressure hose 07ZAJ-S5AA200
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 19.
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, the system is OK at this time. Check for poor connections or loose terminals at the rocker arm oil pressure switch, the rocker arm oil control solenoid and the ECM/PCM.
NO - Go to step 5.
5. Turn the ignition switch OFF.
6. Disconnect the rocker arm oil pressure switch 2P connector.
7. Turn the ignition switch ON (II).
8. Check the VTEC PRES SW in the DATA LIST with the HDS.
Is switch ON indicated?
YES - Go to step 14.
NO - Go to step 9.
9. Turn the ignition switch OFF.
10. Remove the rocker arm oil pressure switch (A) and install the special tools as shown, then install the rocker arm oil pressure switch on the oil pressure gauge adapter (B).
NOTE: Install the parts in the reverse order of removal with a new O-ring.
11. Start the engine.
12. Do the VTEC TEST in the INSPECTION MENU with the HDS.
13. Check the oil pressure.
Does the oil pressure increase to at least 392 kPa (56.9 psi, 4.0 kgf/sq.cm)?
YES - Replace the rocker arm oil pressure switch, then go to step 18.
NO - Inspect the VTEC system. If it is OK. Replace the rocker arm oil control solenoid, then go to step 18.
14. Turn the ignition switch OFF.
15. Jump the SCS line with the HDS.
16. Disconnect ECM/PCM connector A (31P).
17. Check for continuity between ECM/PCM connector terminal A23 and body ground.
Is there continuity?
YES - Repair short in the wire between the ECM/PCM (A23) and the rocker arm oil pressure switch, then go to step 18.
NO - Go to step 25.
18. Reconnect all connectors.
19. Turn the ignition switch ON (II).
20. Reset the ECM/PCM with the HDS.
21. Do the ECM/PCM idle learn procedure.
22. Do the VTEC TEST in the INSPECTION MENU with the HDS.
23. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P2646 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/PCM, then go to step 1.
NO - Go to step 24.
24. Monitor the OBD STATUS for DTC P2646 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 23, go to the indicated DTCs troubleshooting.
NO - If the screen indicates FAILED, check for poor connections or loose terminals at the rocker arm oil pressure switch, the rocker arm oil control solenoid, and the ECM/PCM. If the screen indicates NOT COMPLETED, go to step 22.
25. Reconnect all connectors.
26. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM.
27. Do the VTEC TEST in the INSPECTION MENU with the HDS.
28. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P2646 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/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM, then go to step 27. If the ECM/PCM was substituted, go to step 1.
NO - Go to step 29.
29. Monitor the OBD STATUS for DTC P2646 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 were indicated in step 28, go to the indicated DTCs troubleshooting.
NO - If the screen indicates FAILED, check for poor connections or loose terminals at the rocker arm oil pressure switch, the rocker arm oil control solenoid, and the ECM/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM, then go to step 27. If the ECM/PCM was substituted, go to step 1. If the screen indicates NOT COMPLETED, go to step 27.