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P341D Deactivation/Exhaust Valve Control Circuit Performance Bank 2

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P341D appears once the bank 2 exhaust valves respond wrongly to a deactivation or reactivation request while the electrical side is intact. No manufacturer documents this code publicly. Timing is the critical part: a GM patent application has the exhaust valves stop before the intake valves when a cylinder is switched off and resume before them when it comes back, so that burnt gas is expelled and no fresh charge is trapped. GM's DFM V8, as NHTSA describes it, reverses this and stops the intake side first. If the exhaust side lags, the planned order breaks. CARB expects outputs like this to be checked for proper function. The circuit code for this bank is P340D, the bank 1 equivalent P341C, the intake function on bank 2 P341B. Expect a lamp, harsh mode changes and higher fuel use.

Likely causes

Exhaust lifter or rocker on bank 2 switching late or not at all
Oil too thin, too old or too low for fast switching
Sluggish bank 2 exhaust actuator valve

Symptoms

  • Check engine lamp on
  • Bump or shudder during mode changes
  • Higher fuel consumption

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

P340DP341CP341BP3497

References: law.cornell.edu, patents.google.com, static.nhtsa.gov.