DTC Troubleshooting: P2647
DTC P2647: Rocker Arm Oil Pressure Switch Circuit High Voltage
NOTE:
Before you troubleshoot, 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 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
     
     
     
2.
Problem verification:

Problem verification
?1.
Turn the vehicle to the ON mode.

?2.
Clear the DTC with the HDS.


?3.
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 and the PCM. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot.?
     
NO
     
     
     
The failure is duplicated. Go to step 3.
3.
Rocker arm oil pressure switch internal circuit check:

Rocker arm oil pressure switch internal circuit check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
Rocker arm oil pressure switch 2P connector

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


Is there continuity?

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

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


?2.
Disconnect the following connector.
PCM connector B (51P)

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Rocker arm oil pressure switch 2P connector: disconnected
 
PCM connector B (51P): disconnected
Test point 1
Rocker arm oil pressure switch 2P connector No. 2
Test point 2
PCM connector B (51P) No. 21


Is there continuity?

     
YES
     
     
     
Go to step 5.
     
NO
     
     
     
Repair an open in the VTM wire between the PCM (B21) and the rocker arm oil pressure switch.?
5.
Open wire check (LG line):

Open wire check (LG line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Rocker arm oil pressure switch 2P connector: disconnected
PCM connector B (51P): disconnected
Test point 1
Rocker arm oil pressure switch 2P connector No. 1
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 recheck. If DTC P2647 goes away and the PCM was updated, troubleshooting is complete. If DTC P2647 goes away and the PCM was substituted, replace the original PCM.?
     
NO
     
     
     
Repair an open in the LG wire between the rocker arm oil pressure switch and G101.?