P3407Cylinder 1 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
- P3407 stands for a short to ground in the control circuit of a dedicated exhaust valve actuator on cylinder 1. No manufacturer documents this code publicly, so there are no published thresholds. As an analogy, GM's intake-side code P3403 counts an impedance under 0.5 ohm to ground, seen with the driver off, as a fault. CARB requires such output circuits to be checked for shorts. Engines with one shared solenoid per cylinder, like GM's AFM and DFM V8s, report this fault under the intake-side codes instead. An open exhaust circuit would be P3405, a short to power P3408. The car usually keeps running normally on all cylinders, with a warning lamp.
- What you may notice
- Check engine lamp on
- No change to reduced-cylinder mode
- Likely causes
- PossibleActuator control wire shorted to ground
- PossibleInternal short in the exhaust valve actuator
- RareEngine control module output stage fault
- 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.