P2DECCylinder 3 Intake Valve Lift Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2DEC applies only to cylinder 3: the lift its intake valves actually achieve is outside the commanded window or arrives too late. Under the CARB rule, a maker must run a failure analysis of any plausible hydraulic or mechanical defect, naming broken return springs, blocked oil passages and a single cylinder's lift pin as examples, and must catch the resulting errors before tailpipe emissions pass the threshold. Two-step valvetrains with fixed states get a relief: they only have to detect faults that actually exceed it. Because a cylinder stuck in the wrong lift fills differently from its neighbours, its combustion becomes unsteady, which is exactly what crank-speed methods like GM's patented one measure. No public manufacturer document names P2DEC; an open or shorted actuator would set a circuit code instead.
- What you may notice
- Check engine light on
- Uneven idle, often with a cylinder 3 misfire entry
- Higher fuel consumption
- Likely causes
- LikelyLock pin or switching follower of cylinder 3 not latching
- PossiblePartly blocked oil passage to the cylinder 3 element
- RareBroken return spring in the lift mechanism
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €150 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.