P1656 - FAULT CODE - OBD2

P1656 LEXUS, TOYOTA: OIL CONTROL VALVE CIRCUIT MALFUNCTION

The VVT (Variable Valve Timing) System controls the timing of the intake valve so that it adapts to driving conditions. The Oil Control Valve is included in these systems (OCV). Its function is to regulate oil supply to a designated VVT bucket to advance or retard timing through changes in the camshaft angle position.

The ECM (Engine Control Module) provides the VVT with various electrical signals that inform it of the oil flow adjustment that is required to be made. Since the VVT hubs depend on a continuous and pressurized oil flow for proper performance, the ECM uses the Oil Control Valve to ensure that the valve timing is right, and the pressure is maintained within the proper levels to change the relative position between the camshaft and crankshaft.

Toyota and Lexus vehicle manufacturers use the P1656 OBDII fault code to indicate that a malfunction has been detected in the Oil Control Valve circuit, and it is caused by a short or open circuit.

• Check Engine lamp ON.
• The engine does not start.
• Failures during acceleration.
• Difficulties when braking.
• Higher fuel consumption.

The P1656 OBD2 diagnostic code P1656 is set for the following reasons:

• The Oil Control Valve circuit may have damage to the wiring.
• The OCV circuit connections may not meet the requirements for proper operation.
• The Oil Control Valve may be defective.
• The ECM may be damaged.

To troubleshoot DTC P1656 OBDII, take into account this:

• First, consult the Technical Service Bulletins.
• Check the condition of the OCV wiring and connectors, and check them for common deficiencies. Fix or replace as required.
• Measure the Oil Control Valve circuit voltages and check to see if they are within the parameters set by the manufacturer. If you discover an out-of-range value suggesting a short or open circuit, check the integrity of the wiring and connections. Repair as needed.
• If no damage to the electrical components of the OCV circuit is detected, the valve is likely in poor condition. Proceed to replace it.