OBD-II code P3468 indicates that the powertrain control module (PCM) has detected an abnormally high voltage on the control circuit for the cylinder 9 intake valve deactivation solenoid. This solenoid is part of the cylinder deactivation system (e.g., Active Fuel Management) and is used to disable the intake valves on cylinder 9 to improve fuel economy under light load. A high circuit voltage typically points to a short to voltage, an open circuit, or a faulty solenoid.
The solenoid may have an internal open circuit or high resistance, causing the PCM to see a voltage higher than expected when the circuit is commanded on.
The control wire for the solenoid may be chafed or pinched, making contact with a power source and pulling the circuit voltage high.
Corrosion, bent pins, or a loose connector can create high resistance or an intermittent open, leading to a high voltage reading at the PCM.
Physical damage to the connector body or broken wires near the solenoid can cause an open circuit, which the PCM interprets as high voltage.
An internal failure in the PCM’s solenoid driver circuit is possible but should only be considered after all other causes have been ruled out.
Almost never. The PCM is rarely the cause of a P3468 code. The problem is usually a faulty deactivation solenoid, wiring issue, or poor connection. The PCM should only be considered after thorough testing of the entire circuit.
You can usually drive the vehicle, but you may experience rough running, reduced fuel economy, or hesitation. The cylinder deactivation system may be disabled, so the engine will run on all cylinders continuously. It’s best to diagnose and repair the issue promptly to avoid potential damage to other components.
It is an electrically controlled oil valve that directs oil pressure to deactivate the intake valves on a specific cylinder, allowing the engine to run on fewer cylinders under light load to save fuel. On many engines, these solenoids are part of a manifold assembly called the VLOM (Valve Lifter Oil Manifold).
Diagnosis typically starts with a visual inspection of the wiring and connector, followed by testing the solenoid’s resistance and checking for shorts or opens in the circuit. A scan tool can be used to command the solenoid and monitor circuit operation. Replacing the solenoid or repairing the wiring usually fixes the problem.