DTC Troubleshooting: P2651
DTC P2651: Rocker Arm Oil Pressure Switch B (Bank 1) Performance/Stuck off
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.
If DTC P2653 and/or P2654 are stored at the same time as DTC P2651, troubleshoot those DTCs first, then recheck for DTC P2651.

DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P2651 Rocker Arm Oil Pressure Switch B (Bank 1) Performance/Stuck off
      

1.
Oil level check:

Oil level check
?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 do the repair verification.
2.
Problem verification:

Problem verification
?1.
Press the engine start/stop button to select the ON mode.

?2.
Clear the DTC with the HDS.


?3.
Select the VTEC+VCM TEST in the INSPECTION MENU with the HDS, then select the CDVEB TEST with the HDS.

  

Does the HDS indicate Normal?

     
YES
     
     
     
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at rocker arm oil pressure switch B (Bank 1) and the PCM.?
     
NO
     
     
     
Go to step 3.
3.
Open wire check (VCMSW line):

Open wire check (VCMSW line)
?1.
Press the engine start/stop button to select the OFF mode.

?2.
Disconnect the following connector.

?3.
Press the engine start/stop button to select the ON mode.

?4.
Measure the voltage between test points 1 and 2.
Test condition
ON mode
Rocker arm oil pressure switch B (Bank 1): disconnected
Test circuit
VCMSW
Test point 1
Rocker arm oil pressure switch B (Bank 1) 1P connector No. 1 (TAN)
Test point 2
Body ground


Is there voltage?

     
YES
     
     
     
The VCMSW wire is OK. Go to step 4.
     
NO
     
     
     
Repair an open in the VCMSW wire between PCM (C34) and rocker arm oil pressure switch B (Bank 1), then do the repair verification.
4.
VCM system oil pressure check:

VCM system oil pressure check
?1.
Press the engine start/stop button to select the OFF mode.

?2.
Remove rocker arm oil pressure switch B (Bank 1), and attach the special tools as shown, then attach rocker arm oil pressure switch B (Bank 1) to the oil pressure gauge adapter (B).


?3.
Reconnect rocker arm oil pressure switch B (Bank 1) 1P connector.

?4.
Start the engine.

?5.
Select the VTEC+VCM TEST in the INSPECTION MENU with the HDS, then select the CDVEB TEST with the HDS.

  

?6.
Check the oil pressure.

Is the oil pressure 50 kPa (0.5 kgf/cm2, 7.1 psi) or more?

     
YES
     
     
     
Inspect the VCM system oil passage. If it is OK, replace the rear rocker arm oil control valve, then do the repair verification.
     
NO
     
     
     
Repair verification:

?1.
Reconnect all connectors.

?2.
Press the engine start/stop button to select the ON mode.

?3.
Reset the PCM with the HDS.


?4.
Do the PCM idle learn procedure.

?5.
Select the VTEC+VCM TEST in the INSPECTION MENU with the HDS, then select the CDVEB TEST with the HDS.

  

?6.
Check for Pending or Confirmed DTCs with the HDS.
DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P2651 Rocker Arm Oil Pressure Switch B (Bank 1) Performance/Stuck off
      


Is DTC P2651 indicated?

     
YES
     
     
     
Check for poor connections or loose terminals at rocker arm oil pressure switch B (Bank 1) and the PCM. If the PCM was updated, substitute a known-good PCM, then recheck. If the PCM was substituted, go to step 1.
     
NO
     
     
     
Troubleshooting is complete. If the PCM was substituted, replace the original PCM. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.?