DTC Troubleshooting: P2647 (22)
DTC P2647:
 Rocker Arm Oil Pressure Switch Circuit High Voltage
NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.
  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 go to Step 17 .
  1. Turn the ignition switch ON (II).
  1. Clear the DTC with the HDS.
  1. 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, the rocker arm oil control solenoid, and the ECM.■
NO -
Go to Step 5 .
  1. Check the result of Step 4 .
    • VTEC Switch Failure
    • VTEC Switch Open
    • VTEC Switch SIG Line Open
    • VTEC Switch GND Line Open
Is the test result any of above?
YES -
Go to Step 6 .
NO -
Check for poor connections or loose terminals at the rocker arm oil pressure switch. If it is OK, replace the rocker arm oil control valve, then, go to Step 15 .
  1. Turn the ignition switch OFF.
  1. Disconnect the rocker arm oil pressure switch 2P connector.
  1. 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 9 .
NO -
  1. Turn the ignition switch ON (II).
  1. Measure voltage between rocker arm oil pressure switch 2P connector terminal No. 1 and body ground.
Is there battery voltage?
YES -
NO -
Go to Step 11 .
  1. Turn the ignition switch OFF.
  1. Jump the SCS line with the HDS.
  1. Disconnect ECM connector C (44P).
  1. Check for continuity between rocker arm oil pressure switch 2P connector terminal No. 1 and ECM connector terminal C22.
Is there continuity?
YES -
Go to Step 22 .
NO -
Repair open in the wire between the ECM (C22) and the rocker arm oil pressure switch, then go to Step 16 .
  1. Turn the ignition switch OFF.
  1. Reconnect all connectors.
  1. Turn the ignition switch ON (II).
  1. Reset the ECM with the HDS.
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P2647 indicated?
YES -
Check for poor connections or loose terminals at the rocker arm oil pressure switch, the rocker arm oil control solenoid and the ECM, then go to Step 1 .
NO -
Go to Step 21 .
  1. Monitor the OBD STATUS for DTC P2647 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES -
Troubleshooting is complete. If any other Temporary DTCs or DTCs were indicated in Step 20 , go to the indicated DTC's troubleshooting.■
NO -
If the screen indicates FAILED, go to Step 1 and recheck. If the screen indicates NOT COMPLETED, keep idling until a result comes on.
  1. Reconnect all connectors.
  1. Start the engine, and let it idle.
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P2647 indicated?
YES -
Check for poor connections or loose terminals at the rocker arm oil pressure switch and the ECM. If the ECM was updated, substitute a known-good ECM, then go to Step 24 . If the ECM was substituted, go to Step 1 .
NO -
Go to Step 26 .
  1. Monitor the OBD STATUS for DTC P2647 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES -
If the ECM was updated, troubleshooting is complete. If the ECM was substituted, replace the original ECM. If any other Temporary DTCs or DTCs were indicated in Step 25 , go to the indicated DTC's troubleshooting.■
NO -
If the screen indicates FAILED, check for poor connections or loose terminals at the rocker arm oil pressure switch and the ECM. If the ECM was updated, substitute a known-good ECM, then go to Step 24 . If the ECM was substituted, go to Step 1 . If the screen indicates NOT COMPLETED, keep idling until a result comes on.