Powertrain, shared range

P3406 Cylinder 1 Exhaust Valve Control Performance

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

Where an engine controls the exhaust valves of cylinder 1 separately, P3406 would mean the exhaust side does not follow the command although the circuit checks pass. No manufacturer documents this code publicly. Ford holds a patent that detects an exhaust valve still opening after deactivation through pressure changes in the exhaust, and a GM patent, using one shared control valve, has the exhaust valves deactivate and also reactivate before the intake valves, so a lagging exhaust side is a real failure mode. Production systems from GM and Ford instead check the whole cylinder (GM P3498, Ford P3402). Electrical faults on this channel are P3405, P3407 and P3408; if the cylinder keeps pumping exhaust, the driver may feel roughness.

Likely causes

Insufficient or degraded oil delays exhaust-side switching
Exhaust lifter or rocker of cylinder 1 not latching or unlatching
Exhaust valve actuator sticking

Symptoms

  • Check engine lamp on
  • Rough running or vibration in reduced-cylinder mode
  • Cylinder deactivation suspended

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

P3405P3407P3408P3402P3400

References: law.cornell.edu, patents.google.com, patents.google.com.