P3440Cylinder 5 Exhaust Valve Control Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P3440 closes the cylinder 5 block and stands for a high signal, usually a short to supply voltage, in the circuit of a separate exhaust valve actuator. No manufacturer documents this code publicly. The code only makes sense on an engine with a separate exhaust actuator; a Ford patent, for example, checks via exhaust pressure whether an exhaust valve still opens after deactivation. Current production systems that deactivate cylinder 5 drive both valves from one solenoid, and GM reports a short to power there as P3436, checked with the driver on and a 0.5 ohm limit. If a dedicated exhaust channel did short high, the computer would stop using deactivation and light the lamp. Compare P3437, P3438 and P3439.
- What you may notice
- Check engine lamp on
- Cylinder deactivation unavailable
- Likely causes
- PossibleExhaust actuator control wire shorted to voltage
- PossibleShorted actuator coil
- 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.