Powertrain, generic (extended)

P2CDD Cold Start Cylinder 3 Deactivation/Intake Valve Control Performance

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

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.

Likely causes

Cylinder 3 valves keep opening because the switching element does not unlock
Insufficient oil pressure or flow to the switching gallery right after a cold start
Cylinder 3 control solenoid sticking or leaking internally
Manifold pressure signal biased, so a sealed cylinder looks like it still breathes

Symptoms

  • Malfunction lamp, typically after repeated cold starts
  • Vibration or rough idle shortly after a cold start
  • Engine takes longer to settle into normal running

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–3,000
Time0–10 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

cylinder deactivation solenoid cyl 3intake valve actuatorengine oil

Related codes

P2CDCP2CDEP3418P349AP0303

References: law.cornell.edu, gsi.ext.gm.com, patents.google.com.