Powertrain, shared range

P3412 Cylinder 2 Deactivation/Intake Valve Control Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

On GM's L84 V8 each cylinder, including cylinder 2, has a valve lifter oil solenoid bolted into the block valley. NHTSA's description of the system notes these solenoids are driven with peak-and-hold current for fast response. P3412 is set when the control line for cylinder 2 is shorted to supply voltage: GM checks it with the driver on and treats under 0.5 ohm to power as failed, 20 of 25 samples at 250 ms, Type B. In that state the computer cannot pull the solenoid properly and drops cylinder 2 from deactivation. Related codes are P3409 for an open circuit, P3411 for a short to ground and P3410 when the circuit is fine but the cylinder does not respond.

Likely causes

Control wire shorted to a voltage feed in the harness
Low-resistance coil in the cylinder 2 solenoid
Engine control module output stage fault

Symptoms

  • Check engine lamp on
  • Cylinder deactivation no longer active

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

P3409P3410P3411P3416P3497

References: law.cornell.edu, gsi.ext.gm.com, static.nhtsa.gov.