Powertrain, generic (extended)

P2395 Diesel Intake Air Flow B Control Stuck Closed

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2395 reports a B intake throttle that remains nearer to its closed stop than the module asks for. Of the two stuck faults this is the more serious one, because a flap jammed near its seat starves the engine of air. No manufacturer publishes thresholds for P2395. The GM 2017 diesel check for valve A (P02E5) mirrors the stuck-open test: a positive error above 16 % while the motor is driven at more than 34 % duty towards opening, 1,280 of 1,600 samples, MIL in the first trip. Deposits that lock the flap close to its stop, an iced shaft after cold and damp nights, or a broken return spring are the usual reasons. The engine may smoke, lose power markedly, drop into limp mode or even stall; low-air-flow codes such as P239D often follow.

Likely causes

Deposits locking the flap near its closed stop
Broken return spring, flap no longer opens when unpowered
Jammed gear train or seized shaft bearing
Ice on the shaft or flap after cold, damp conditions

Symptoms

  • Marked loss of power, limp mode
  • Black smoke under load
  • Rough running or stalling in severe cases

Repair estimate

DifficultyMediumDIY possible
Parts and labour€50–600
Time0.5–2.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

diesel intake throttle valvethrottle valve motoractuator wiring

Related codes

P2394P2391P239DP02E5P0299

References: law.cornell.edu, gsi.ext.gm.com, ms-motorservice.com.