DTC Troubleshooting: P2647 (22)

DTC P2647:  VTEC Oil Pressure Switch Circuit High Voltage


1.Check the engine oil level.

Is the level OK?


YES - Go to 2.


NO - Adjust the engine oil to the proper level, then go to 14.


2.Turn the ignition switch ON (II).

3.Do the DTC CLEAR in the CLEAR MENU with the Honda PGM tester or the HDS.

4.Do the VTEC TEST in the INSPECTION MENU with the Honda PGM tester or the HDS.

Is the result OK?


YES - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the  VTEC oil pressure switch and the  ECM/PCM.n


NO - Go to 5.


5.Check the result in the display.

Does it indicate ‘‘Possible Problem''?


YES - Check for poor connections or loose terminals at the  VTEC oil pressure switch. If it is OK,replace the VTEC solenoid valve, then go to 15.


NO - Go to 6.


6.Turn the ignition switch OFF.

7.Disconnect the VTEC oil pressure switch 2P connector.

8.Check for continuity between VTEC oil pressure switch terminal No. 2 and body ground.

Is there continuity?


YES - Go to 9.


NO - Repair open in the wire between the VTEC oil pressure switch and G101, then go to 14.


9.Jump the SCS line with the Honda PGM Tester or the HDS.

10.Disconnect ECM/PCM connector B (24P).

11.Connect VTEC oil pressure switch 2P connector terminal No. 1 to body ground with a jumper wire.

12.Check for continuity between ECM/PCM connector terminal B11 and body ground.

Is there continuity?


YES - Replace the VTEC oil pressure switch, then go to 13. If the VTEC oil pressure switch is OK, go to 21.


NO - Repair open in the wire between the ECM/PCM (B11) and the VTEC oil pressure switch, then go to 13.


13.Reconnect ECM/PCM connector B (24P).

14.Reconnect the VTEC oil pressure switch 2P connector.

15.Turn the ignition switch ON (II).

16.Do the ECM/PCM RESET in the CLEAR MENU with the Honda PGM Tester or the HDS.

17.Do the ECM/PCM idle learn procedure.

18.Start the engine. Hold the engine speed at 3,000 rpm (min-1) with no load (in Park or neutral) until the radiator fan comes on, then let it idle.

19.Check for Temporary DTCs or DTCs in the DTCs MENU with the Honda PGM Tester or the HDS.

Are any Temporary DTCs or DTCs indicated?


YES - If DTC P2647 is indicated, check for poor connections or loose terminals at the  VTEC oil pressure switch and the  ECM/PCM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC troubleshooting.


NO - Go to 20.


20.Monitor the OBD STATUS for DTC P2647 in the DTCs MENU with the Honda PGM Tester or the HDS.

Is it PASSED?


YES - Troubleshooting is complete.n


NO - If it is FAILED, then go to 1. and recheck. If it is NOT COMPLETED, go to 18. and recheck.


21.Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM.

22.Start the engine. Hold the engine speed at 3,000 rpm (min-1) with no load (in Park or neutral) until the radiator fan comes on, then let it idle.

23.Check for Temporary DTCs or DTCs in the DTCs MENU with the Honda PGM Tester or the HDS.

Are any Temporary DTCs or DTCs indicated?


YES - If DTC P2647 is indicated, check for poor connections or loose terminals at the  VTEC oil pressure switch and the  ECM/PCM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC troubleshooting.


NO - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM.n