P2397Diesel Intake Air Flow B Position Sensor Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- P2397 covers a B-throttle position signal that stays inside its electrical window but does not make sense, for instance a reading that does not move when the motor is driven, or one that disagrees with the commanded angle. CARB asks for such rationality checks on inputs wherever feasible. No published manufacturer table covers P2397. The 6.6 L LML calibration from GM handles the A valve this way under P02E7 and flags a control deviation beyond ±10 % lasting 10 s. Because a sticking flap and a drifting sensor produce the same pattern, compare the scan-tool angle with the real flap position and check the sensor's contact resistance before blaming the actuator. The MIL and reduced EGR control are the main effects; some engines also cut power.
- What you may notice
- MIL on
- Displayed flap angle does not follow the command
- Occasionally reduced power
- Likely causes
- LikelySticking flap that lags behind the command
- PossibleWorn potentiometer track or drifting sensor
- PossibleContact resistance in connector or signal wire
- RarePlay between gear and flap shaft
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €50 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.