Powertrain, generic (extended)

P2D31 Intake Manifold Tuning Valve Exceeded Learning Limit Bank 1

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

An intake manifold tuning valve switches the effective volume or length of the intake to use pressure waves for more cylinder filling. Electrically positioned versions learn the feedback value at their end stop, and P2D31 says that learned value lies outside its tolerance band. GM uses the code on the 2023 and 2024 Corvette Z06 with the 5.5 l LT6, whose two plenums are linked by three servo-driven communicator valves. Tables 23OBDG07 and 24OBDG07 average the feedback voltage of tuning valve 1 at the closed stop and fail it above 4.5 V or below 4.25 V for 1 s, battery 9 to 17.5 V, with P2076 to P2078 and P0660 absent; MIL after two trips. Tuning valve 2 has its own GM codes. Typical reasons are a worn stop, a bent valve or a drifting sensor; power can suffer in certain rev bands.

Likely causes

Worn end stop or deposits changing the closed position of the valve
Bent valve plate or shaft after mechanical stress
Position sensor inside the actuator drifting
Actuator replaced without completing the relearn

Symptoms

  • Check engine light
  • Less torque in some engine speed ranges
  • Changed intake sound under load

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€150–1,000
Time0.5–4 h

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

Parts involved

intake manifold tuning valve b1ecm

Related codes

P2D32P0660P2076P2077P2078P2070P2071

References: gsi.ext.gm.com, gsi.ext.gm.com, mobilityengineeringtech.com.