P3495Cylinder 12 Exhaust Valve Control Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P3495 points to a low signal, usually a short to ground, on the control line of the cylinder 12 exhaust valve actuator. No manufacturer documents this code publicly; J2012 reserves the codes for cylinders 9 to 12 for engines with more than eight cylinders. The twelve-cylinder engines with deactivation (Bentley W12, Lamborghini Aventador V12, Mercedes M137) are not documented with a dedicated exhaust actuator per cylinder; the newer ones shut entire banks and keep the valves moving, as Bentley states for its W12. Where such an actuator does exist, the diagnosis follows the usual path: connector unplugged, resistance of the wire to ground, then the coil itself. P3493 is the open circuit, P3496 the short to voltage, and P3491 the low fault on the intake side of cylinder 12.
- What you may notice
- Check engine lamp on
- Cylinder deactivation inactive
- Likely causes
- PossibleExhaust actuator wire of cylinder 12 grounded
- PossibleExhaust actuator with internal short
- RareControl module output faulty
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €60 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.