P2D31Intake Manifold Tuning Valve Exceeded Learning Limit Bank 1
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- 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.
- What you may notice
- Check engine light
- Less torque in some engine speed ranges
- Changed intake sound under load
- Likely causes
- LikelyWorn end stop or deposits changing the closed position of the valve
- PossibleBent valve plate or shaft after mechanical stress
- PossiblePosition sensor inside the actuator drifting
- RareActuator replaced without completing the relearn
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €150 – €1,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.