DTC Troubleshooting
DTC Troubleshooting: P2646, P2646
DTC P2646:
Rocker Arm Oil Pressure Switch Circuit Low Voltage
Special Tools Required
- Pressure Gauge Adapter 07NAJ-P07010A
- A/T Low Pressure Gauge w/Panel 07406-0070301
- A/T Pressure Test Hose 07AAJ-PY4A100
- 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 Initial Inspection and Diagnostic Overview.
1. Check the engine oil level.
Is the level OK?
YES -
Go to step 2.
NO -
Adjust the engine oil to the proper level, then go to step 20.
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, the rocker arm oil control solenoid, and the ECM/PCM.�
NO -
Go to step 5.
5. Turn the ignition switch to LOCK (0).
6. Disconnect the rocker arm oil pressure switch 2P connector.
7. Turn the ignition switch to ON (II).
8. Check the VTEC PRES SW in the DATA LIST with the HDS.
Is SWITCH ON indicated?
YES -
Go to step 15.
NO -
Go to step 9.
9. Turn the ignition switch to LOCK (0).
10. Remove the rocker arm oil pressure switch (A), and attach the special tools as shown, then attach the rocker arm oil pressure switch to the oil pressure gauge adapter (B).
11. Reconnect the rocker arm oil pressure switch 2P connector.
12. Start the engine.
13. Do the VTEC TEST in the INSPECTION MENU with the HDS.
14. Check the oil pressure.
Does the oil pressure increase to at least 392 kPa (4.0 kgf/cm2, 56.9 psi)?
YES -
Replace the rocker arm oil pressure switch Service and Repair, then go to step 19.
NO -
Check the engine oil pressure Testing and Inspection. If the pressure is OK, inspect the VTEC system. If it is OK, replace the rocker arm oil control valve Rocker Arm Oil Control Valve Removal/Installation, then go to step 19.
15. Turn the ignition switch to LOCK (0).
16. Jump the SCS line with the HDS.
17. Disconnect ECM/PCM connector C (49P).
18. Check for continuity between ECM/PCM connector terminal C22 and body ground.
Is there continuity?
YES -
Repair short in the wire between the ECM/PCM(C22) and the rocker arm oil pressure switch, then go to step 19.
NO -
Go to step 25.
19. Reconnect all connectors.
20. Turn the ignition switch to ON (II).
21. Reset the ECM/PCM with the HDS.
22. Do the ECM/PCM idle learn procedure ECM/PCM Idle Learn Procedure (M/T).
23. Do the VTEC TEST in the INSPECTION MENU with the HDS.
24. Check for Pending or Confirmed 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 step 1.
NO -
Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.�
25. Reconnect all connectors.
26. Update the ECM/PCM if it does not have the latest software ECM/PCM Update (M/T), or substitute a known-good ECM/PCM.
27. Do the VTEC TEST in the INSPECTION MENU with the HDS.
28. Check for Pending or Confirmed 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 -
If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM Service and Repair. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.�