Powertrain, shared range

P341C Deactivation/Exhaust Valve Control Circuit Performance Bank 1

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P341C covers exhaust valves on bank 1 that ignore a deactivation command while their wiring and actuator coil check out. No manufacturer documents this code publicly. A Ford patent explains why it matters and how to spot it: a sealed cylinder whose exhaust valve keeps lifting leaves a trace in exhaust pressure, and the controller can respond by reactivating the cylinder, blocking further deactivation and storing a fault. Production engines control both valve sets per cylinder jointly, so GM, for instance, files such faults under its own per-cylinder codes from P3498. Electrically this circuit reports P340C; intake function on bank 1 is P341A, bank 2 exhaust P341D.

Likely causes

Exhaust-side lifter or rocker on bank 1 not switching
Low oil pressure or foaming oil
Bank 1 exhaust deactivation actuator sticking

Symptoms

  • Check engine lamp on
  • Popping or uneven exhaust note in reduced-cylinder mode
  • 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

P340CP341AP341DP3400P3498

References: law.cornell.edu, patents.google.com, gsi.ext.gm.com.