DTC Troubleshooting: P2647
DTC P2647: Rocker Arm Oil Pressure Switch A (Bank 1) Circuit High Voltage
NOTE:
Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.
If DTC P2648 and/or P2649 are stored at the same time as DTC P2647, troubleshoot those DTCs first, then recheck for DTC P2647.

DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P2647 Rocker Arm Oil Pressure Switch A (Bank 1) Circuit High Voltage
      

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 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 pressure switch A (Bank 1) and the PCM.?
     
NO
     
     
     
The failure is duplicated. Go to step 3.
3.
Rocker arm oil pressure switch A (Bank 1) internal circuit check:

Rocker arm oil pressure switch A (Bank 1) internal circuit check
?1.
Press the engine start/stop button to select the OFF mode.

?2.
Disconnect the following connector.

?3.
At the rocker arm oil pressure switch side, check for continuity between test points 1 and 2.
Test condition
OFF mode
 
Rocker arm oil pressure switch A (Bank 1) 2P connector: disconnected
Test circuit
VTMB1, LG
Test point 1
Rocker arm oil pressure switch A (Bank 1) 2P connector No. 1 (rocker arm oil pressure switch side)
Test point 2
Rocker arm oil pressure switch A (Bank 1) 2P connector No. 2 (rocker arm oil pressure switch side)


Is there continuity?

     
YES
     
     
     
Go to step 4.
     
NO
     
     
     
4.
Open wire check (VTMB1 line):

Open wire check (VTMB1 line)
?1.
Jump the SCS line with the HDS.


?2.
Disconnect the following connector.

?3.
Check for continuity between test points 1 and 2.
Test condition
OFF mode
 
Rocker arm oil pressure switch A (Bank 1) 2P connector: disconnected
 
PCM connector C (51P): disconnected
Test circuit
VTMB1
Test point 1
Rocker arm oil pressure switch A (Bank 1) 2P connector No. 2 (PUR)
Test point 2
PCM connector C (51P) No. 22 (PUR)


Is there continuity?

     
YES
     
     
     
Go to step 5.
     
NO
     
     
     
Repair an open in the VTMB1 wire between rocker arm oil pressure switch A (Bank 1) and the PCM (C22), then do the repair verification.
5.
Open wire check (LG line):

Open wire check (LG line)
?1.
Check for continuity between test points 1 and 2.
Test condition
OFF mode
 
Rocker arm oil pressure switch A (Bank 1) 2P connector: disconnected
Test circuit
LG
Test point 1
Rocker arm oil pressure switch A (Bank 1) 2P connector No. 1 (BRN)
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
The LG wire is OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM, then do the repair verification.
     
NO
     
     
     
Repair an open in the LG wire between rocker arm oil pressure switch A (Bank 1) and G101, then do the repair verification.
Repair verification:

?1.
Reconnect all connectors.

?2.
Exit the SCS mode with the HDS.


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

?4.
Reset the PCM with the HDS.


?5.
Do the PCM idle learn procedure.

?6.
Start the engine, and let it idle.

?7.
Check for Pending or Confirmed DTCs with the HDS.
DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P2647 Rocker Arm Oil Pressure Switch A (Bank 1) Circuit High Voltage
      


Is DTC P2647 indicated?

     
YES
     
     
     
Check for poor connections or loose terminals at rocker arm oil pressure switch A (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.?