P3439Cylinder 5 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
- P3439 would report a short to ground in the control circuit of a dedicated exhaust valve actuator on cylinder 5. No manufacturer documents this code publicly, and no threshold is published for it. The closest documented reference is the intake-side P3435, which GM's L84 sets at under 0.5 ohm to ground with the driver off, after 20 of 25 samples. CARB's output component rules call for exactly this kind of short-circuit check on any actuator that can affect emissions. Engines that switch both valves of cylinder 5 with one solenoid report a short only through P3435. Exhaust-side siblings are P3437 (open), P3438 (function) and P3440 (short to power).
- What you may notice
- Check engine lamp on
- Engine runs on all cylinders only
- Likely causes
- PossibleControl wire of the exhaust actuator grounded
- PossibleInternally shorted exhaust actuator
- RareFaulty engine control module output
- 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.