Advanced Diagnostics

DTC P2647: Rocker Arm Oil Pressure Switch Circuit High Voltage




General Description
The VTEC system activates the rocker arm oil control solenoid by command from the engine control module (ECM)/powertrain control module (PCM), and it charges/discharges the hydraulic circuit of the VTEC mechanism that switches valve timing between Low and High. The ECM/PCM monitors oil pressure in the hydraulic circuit of the VTEC mechanism using the rocker arm oil pressure switch downstream of the rocker arm oil control solenoid. If there is a difference between the oil pressure condition in the hydraulic circuit that is determined by the ECM/PCM command and the oil pressure condition that is determined by the status of the rocker arm oil pressure switch, the system is considered faulty, and a DTC is stored.




Monitor Execution, Sequence, Duration, DTC Type, OBD Status




Enable Conditions

Malfunction Threshold
Low lift cam operation

When the rocker arm oil control solenoid is OFF, the rocker arm oil pressure switch remains OFF.

Confirmation Procedure with the HDS
Do the VTEC TEST in the INSPECTION MENU with the HDS.

Driving Pattern
Start the engine, and let it idle for at least 7 seconds.

Diagnosis Details

Conditions for illuminating the MIL
When a malfunction is detected, the MIL comes on and the DTC and the freeze frame data are stored in the ECM/PCM memory.

Conditions for clearing the MIL
The MIL will be cleared if the malfunction does not recur during three consecutive trips in which the diagnostic runs.

The MIL, the DTC, and the freeze frame data can be cleared by using the scan tool Clear command or by disconnecting the battery.