VTEC System Stuck OFF

DTC P2646: VTEC System Stuck OFF (Engine Type: J35A7)




General Description
The variable cylinder management (VCM) system activates the rocker arm oil control solenoid by command from the powertrain control module (PCM), and it charges/discharges the hydraulic circuit of the cylinder pause VTEC system that pauses the intake and exhaust valves on the rear bank. The PCM monitors oil pressure in the hydraulic circuit of the VTEC mechanism using the engine oil pressure (EOP) sensor 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 PCM command and the oil pressure condition that is determined by the status of the EOP sensor, the system is considered faulty, and a DTC is stored.




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




Enable Conditions

Malfunction Threshold
When the rocker arm oil control solenoid is OFF, the EOP sensor output remains Low (39 kPa (11.5 in.Hg, 292 mmHg) or less).

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 5 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 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.