Low engine oil level
Faulty Rocker Arm Oil Control Solenoid
Faulty EOP (Engine Oil Pressure) sensor
Incorrect oil type used
Engine mechanical condition
Engine Light ON (or Service Engine Soon Warning Light)
The VTEC system activates rocker arm oil control solenoid B by command from the Powertrain Control Module (PCM), and it charges/discharges the hydraulic circuit of the VTEC mechanism that switches valve timing between Low and High. The PCM monitors oil pressure in the hydraulic circuit of the VTEC mechanism using rocker arm oil pressure switch B downstream of rocker arm oil control solenoid B. If there is a difference between the oil pressure condition in the hydraulic circuit determined by the PCM command and the oil pressure condition determined by the status of rocker arm oil pressure switch B, the system is considered faulty, and a DTC is stored.