Powertrain, shared range

P3492 Cylinder 12 Deactivation/Intake Valve Control Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P3492 records a high condition on the control circuit of the cylinder 12 deactivation or intake valve actuator, generally a short to a supply voltage seen while the output is commanded on. No manufacturer documents this code publicly; J2012 reserves the codes for cylinders 9 to 12 for engines with more than eight cylinders. The Variable displacement overview notes that a V12 can stop up to six cylinders, and the production engines doing so (Mercedes M137, Lamborghini Aventador, Bentley W12) differ widely in method, from a hydraulic solenoid pack (M137) to bank shut-off with the valves left running (Bentley). Only a design with valve actuators has a cylinder 12 actuator to short. Expect deactivation to be inhibited and the engine to run on all twelve. P3489 and P3491 are the electrical siblings, P3496 the exhaust high code.

Likely causes

Cylinder 12 control wire shorted to supply voltage
Shorted turns in the cylinder 12 actuator
Engine control module output damaged

Symptoms

  • Check engine lamp on
  • Engine runs permanently on twelve cylinders

Repair estimate

DifficultyMediumDIY possible
Parts and labour€60–900
Time0.5–4 h

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

Parts involved

cylinder deactivation solenoidwiring harnessecm

Related codes

P3489P3490P3491P3496P3497

References: law.cornell.edu, en.wikipedia.org, en.wikipedia.org, newatlas.com.