Powertrain, generic (extended)

P2DF1 Intake Valve Lift Range/Performance Bank 2

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2DF1 is the bank 2 counterpart of P2DF0 and therefore only appears on V engines or boxers, on the side without cylinder 1. Nissan's VVEL, used on the VQ37VHR V6 and on V8 engines, is a good example: on the 2014 QX80 V8 both banks carry a separate VVEL ladder assembly with an actuator and a control shaft position sensor. Infiniti's bulletin ITB14-041 for the 2014 QX80 warns never to loosen the ladder adjusting bolts or the sensor mounting bolts, because the cam lift stroke then goes out of adjustment and ladder plus cylinder head must be replaced. A wrong reading from that sensor or a binding shaft therefore shows up as a lift error on one bank only. No manufacturer documents P2DF1 publicly; under CARB's VVT section the lift system must be watched for both kinds of deviation.

Likely causes

Control shaft or ladder assembly on bank 2 binding
Control shaft position sensor on bank 2 moved or faulty
Lift actuator motor of bank 2 weak
Oil sludge in the bank 2 lift mechanism

Symptoms

  • Check engine light on
  • Uneven running between the banks, possible fuel trim difference
  • Reduced power

Repair estimate

DifficultyHardWorkshop job
Parts and labour€200–4,000
Time1–14 h

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

Parts involved

intake valve lift systemvvt system

Related codes

P2DF0P2DF2P2DEFP0028P2656

References: law.cornell.edu, static.nhtsa.gov, en.wikipedia.org.