Check engine oil level, oil condition and pressure
Faulty Variable Valve Timing and Lift Electronic Control (VTEC) / Rocker Arm Solenoid Valve
VTEC/Rocker Arm Solenoid Valve harness is open or shorted
VTEC/Rocker Arm Solenoid Valve circuit poor electrical connection
Engine Light ON (or Service Engine Soon Warning Light)
Code P2648 Acura Description
The Variable Valve Timing and Lift Electronic Control (VTEC) system activates the Rocker Arm Oil Control Solenoid (VTEC Solenoid Valve) 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 (VTEC oil pressure switch) downstream of the rocker arm oil control solenoid (VTEC solenoid valve). 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 (VTEC oil pressure switch), the system is considered faulty, and the Diagnostic Trouble Code (DTC) is stored.
P2648 Acura Code – Rocker Arm Oil Control Solenoid Circuit Low Voltage