Powertrain, shared range

P3466 Cylinder 9 Deactivation/Intake Valve Control Performance

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P3466 is the plausibility test for cylinder 9: its actuator circuit is electrically sound, yet the cylinder fails to change state when the engine computer commands it. No manufacturer documents this code publicly; J2012 reserves the codes for cylinders 9 to 12 for engines with more than eight cylinders. In valve-based systems the switching happens hydraulically; NHTSA's account of GM's design describes oil pressure moving locking pins inside the lifter. The Mercedes M137 V12, whose shut-off system relied on a solenoid pack and oil pressure tubes, is known for trouble with exactly those parts, exactly the kind of fault this code targets. Bank-switching V10 and W12 engines from Audi and Bentley leave the valves running and have nothing comparable to check. P3465, P3467 and P3468 are the electrical faults of cylinder 9.

Likely causes

Oil level, pressure or quality too poor to switch cylinder 9
Leak at the oil tubes or solenoid pack feeding cylinder 9
Switching lifter of cylinder 9 sticking
Solenoid valve slow or sticking mechanically

Symptoms

  • Check engine lamp on
  • Misfire count on cylinder 9 (P0309)
  • Rough running while switching between full and partial mode

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–3,500
Time0–12 h

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

Parts involved

cylinder deactivation solenoidlifterengine oil

Related codes

P3465P3467P3468P3470P3400P0309

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