Powertrain, generic (extended)

P2DEF Cylinder 6 Intake Valve Lift Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2DEF covers cylinder 6, typically on a V6 or straight six: its intake valves do not reach the commanded lift or take too long to switch. Detection follows the same idea as for the other cylinders; for the driver the reaction matters more. GM's patent on stuck lift mechanisms reports which cylinder failed and whether it hangs in high or low lift, and the engine computer may then drive every mechanism into one default lift, stop further switching, limit engine speed and turn on the MIL. When several cylinders on one bank or the whole engine are off target, P2DF0, P2DF1 or P2DF2 are the matching codes instead. No manufacturer documents P2DEF publicly; CARB treats any lift error that raises emissions as an OBD fault.

Likely causes

Lift mechanism of cylinder 6 stuck in high or low lift
Restricted oil feed to the cylinder 6 element
Actuator for cylinder 6 slow despite correct wiring

Symptoms

  • Check engine light on
  • Engine speed limited or lift switching disabled (substitute mode)
  • Cylinder 6 misfire, rough running

Repair estimate

DifficultyHardWorkshop job
Parts and labour€150–2,500
Time1–8 h

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

Parts involved

intake valve lift actuator cyl 6vvt system

Related codes

P2DEEP2DEAP2DF1P0306P2CE0

References: law.cornell.edu, image-ppubs.uspto.gov.