P3455Cylinder 7 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
- P3455 points to a ground fault on the line that would drive an exhaust-only actuator on cylinder 7. No manufacturer documents this code publicly. On GM V8 engines, AFM and DFM alike, a single lifter oil solenoid serves intake and exhaust of each cylinder, so a grounded line there sets the intake-side code P3451: the low-side driver is switched off, the output reads under 0.5 ohm to ground, and 20 of 25 checks taken every 250 ms must fail (Type B). On FCA's Hemi, MDS wiring rubbed through by the heat shield behind the driver-side head, next to cylinder 7, shows up as P3449. With its control line grounded, the actuator could switch on uncommanded, so the cylinder may lose its valve motion while fuel still flows. P3453 is the open, P3456 the short to power.
- What you may notice
- Check engine lamp on
- Cylinder deactivation locked out
- Rough running or misfire on cylinder 7 if the actuator pulls in unbidden
- Likely causes
- LikelyActuator wire chafed through against the cylinder head or a heat shield
- PossibleActuator coil shorted to its housing
- RareOutput stage in the engine control module damaged
- 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.