Powertrain, shared range

P341A Deactivation/Intake Valve Control Circuit Performance Bank 1

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P341A is the function check behind P340A: the bank 1 intake deactivation circuit is electrically sound, yet the valves do not end up where they were commanded. No manufacturer documents this code publicly. Comparable checks exist under other numbers. GM's LT4 compares a modeled and a measured manifold pressure with and without deactivation and reports the bank result as P3400; per-cylinder failures on DFM engines go to P3498 onward. A Delphi patent notes why averaged manifold pressure alone separates working and failed intake deactivation poorly and cannot name the cylinder. Typical causes are hydraulic: low or dirty oil, a sticking control valve, lifters that do not latch. Misfires and rough running are possible.

Likely causes

Low oil level or aged, contaminated oil
Bank 1 deactivation control valve sticking or screen blocked
Switchable lifters or rockers on bank 1 not latching or releasing
Insufficient oil pressure from a worn pump or leaking seal

Symptoms

  • Check engine lamp on
  • Jerk or vibration when cylinders switch off or on
  • Misfire codes on bank 1

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

P340AP341BP341CP3400P3498

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