P2CDDCold Start Cylinder 3 Deactivation/Intake Valve Control Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P2CDD flags cylinder 3 when its deactivation or intake valve control misbehaves during the cold start phase. No maker documents this code publicly, so the closest evidence comes from neighbouring checks. GM's L84 V8 judges cylinder 3 outside cold start under P349A: if filtered manifold pressure stays above a threshold while the cylinder should be sealed, and that happens in 22 of 25 chances, a Type B fault (lamp after two trips) is set. A Delphi patent explains the cold start purpose: fuel and spark are cut on chosen cylinders, their valves are closed, and the remaining cylinders burn more fuel so the exhaust reaches the converter hotter. If cylinder 3 keeps breathing, that heating benefit fades and cold start emissions rise; P3418 covers its ordinary performance check.
- What you may notice
- Malfunction lamp, typically after repeated cold starts
- Vibration or rough idle shortly after a cold start
- Engine takes longer to settle into normal running
- Likely causes
- LikelyCylinder 3 valves keep opening because the switching element does not unlock
- PossibleInsufficient oil pressure or flow to the switching gallery right after a cold start
- PossibleCylinder 3 control solenoid sticking or leaking internally
- RareManifold pressure signal biased, so a sealed cylinder looks like it still breathes
- 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: €100 – €3,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.