DTC Troubleshooting
DTC Troubleshooting: P128B
DTC P128B:
Valve Pause System (VPS) Malfunction
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. Turn the ignition switch to ON (II).
2. Clear the DTC with the HDS.
3. Check for Pending or Confirmed DTCs with the HDS.
Are DTC P128B and P1287 indicated at the same time?
YES -
Go to troubleshooting for DTC P1287.�
NO -
Go to step 4.
4. Turn the ignition switch to LOCK (0).
5. Check the engine oil level.
Is the level OK?
YES -
Go to step 6.
NO -
Adjust the engine oil to the proper level, then go to step 23.
6. Turn the ignition switch to ON (II).
7. Clear the DTC with the HDS.
8. 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 rocker arm oil control solenoid 1, rocker arm oil control solenoid 2, the rocker arm oil pressure switch, the rocker arm oil pressure sensor, and the PCM.�
NO -
Depending on the result, go to the appropriate step:
- ROCKER ARM OIL CONTROL SOLENOID 2 STUCK OFF: Go to step 9.
- ROCKER ARM OIL PRESSURE SWITCH HIGH VOLTAGE: Go to step 11.
9. Turn the ignition switch to LOCK (0).
10. Replace the rocker arm oil control valve Service and Repair, then go to step 23.
11. Turn the ignition switch to LOCK (0).
12. Disconnect the rocker arm oil pressure switch 2P connector.
13. At the rocker arm oil pressure switch side, check for continuity between rocker arm oil pressure switch 2P connector terminals No. 1 and No. 2.
Is there continuity?
YES -
Go to step 14.
NO -
Replace the rocker arm oil pressure switch Service and Repair, then go to step 21.
14. Connect rocker arm oil pressure switch 2P connector terminal No. 2 to body ground with a jumper wire.
15. Turn the ignition switch to ON (II).
16. Check the ROCKER ARM OIL PRESSURE SWITCH in the DATA LIST with the HDS.
Does it indicate ON?
YES -
Repair open in the wire between the rocker arm oil pressure switch and G102 Connector and Harness Locations, then go to step 21.
NO -
Go to step 17.
17. Turn the ignition switch to LOCK (0).
18. Jump the SCS line with the HDS.
19. Disconnect PCM connector C (44P).
20. Check for continuity between rocker arm oil pressure switch 2P connector terminal No. 2 and PCM connector terminal C33.
Is there continuity?
YES -
Go to step 29.
NO -
Repair open in the wire between the PCM(C33) and the rocker arm oil pressure switch, then go to step 21.
21. Turn the ignition switch to LOCK (0).
22. Reconnect all connectors.
23. Turn the ignition switch to ON (II).
24. Reset the PCM with the HDS.
25. Do the PCM idle learn procedure PCM Idle Learn Procedure.
26. Do the VTEC TEST in the INSPECTION MENU with the HDS.
27. Check for Pending or Confirmed DTCs with the HDS.
Is DTC P128B indicated?
YES -
Check for poor connections or loose terminals at rocker arm oil control solenoid 1, rocker arm oil control solenoid 2, the rocker arm oil pressure switch, the rocker arm oil pressure sensor, and the PCM, then go to step 1.
NO -
Go to step 28.
28. Monitor the OBD STATUS for DTC P128B in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES -
Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 27, go to the indicated DTC's troubleshooting.�
NO -
If the screen indicates FAILED, check for poor connections or loose terminals at rocker arm oil control solenoid 1, rocker arm oil control solenoid 2, the rocker arm oil pressure switch, the rocker arm oil pressure sensor, and the PCM, then go to step 1. If the screen indicates EXECUTING, keep testing until a result comes on. If the screen indicates OUT OF CONDITION, go to step 26.
29. Reconnect all connectors.
30. Update the PCM if it does not have the latest software PCM Update, or substitute a known-good PCM Initial Inspection and Diagnostic Overview.
31. Do the VTEC TEST in the INSPECTION MENU with the HDS.
32. Check for Pending or Confirmed DTCs with the HDS.
Is DTC P128B indicated?
YES -
Check for poor connections or loose terminals at rocker arm oil control solenoid 1, rocker arm oil control solenoid 2, the rocker arm oil pressure switch, the rocker arm oil pressure sensor, and the PCM. If the PCM was updated, substitute a known-good PCM Initial Inspection and Diagnostic Overview, then go to step 31. If the PCM was substituted, go to step 1.
NO -
Go to step 33.
33. Monitor the OBD STATUS for DTC P128B 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 Service and Repair. If any other Pending or Confirmed DTCs were indicated in step 32, go to the indicated DTC's troubleshooting.�
NO -
If the screen indicates FAILED, check for poor connections or loose terminals at rocker arm oil control solenoid 1, rocker arm oil control solenoid 2, the rocker arm oil pressure switch, the rocker arm oil pressure sensor, and the PCM. If the PCM was updated, substitute a known-good PCM Initial Inspection and Diagnostic Overview, then go to step 31. If the PCM was substituted, go to step 1. If the screen indicates EXECUTING, keep testing until a result comes on. If the screen indicates OUT OF CONDITION, go to step 31.