P2397 code meaning
Diesel Intake Air Flow B Position Sensor Range/Performance
Powertrain system Generic code P23xx codes Check engine light
What P2397 means
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.
P2397 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2.5 hours
- Clears after repairAfter a drive cycle
Symptoms of P2397
- MIL on
- Displayed flap angle does not follow the command
- Occasionally reduced power
Common causes of P2397
- Most likelySticking flap that lags behind the command
- PossibleWorn potentiometer track or drifting sensor
- PossibleContact resistance in connector or signal wire
- Less likelyPlay between gear and flap shaft
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Diesel intake throttle position sensorDiesel intake throttle valveSensor wiring
What each part of P2397 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 3 | Area: ignition system or misfire. |
| 97 | The exact fault in that area. |
What to do next
- Note P2397 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2397
What does P2397 mean?
P2397 means "Diesel Intake Air Flow B Position Sensor Range/Performance". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P2397?
Drive gently and only to a workshop. With P2397 the car can go into limp mode (reduced power) to protect itself.
Will P2397 fail an emissions test?
Yes, it can. P2397 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2397 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P2397 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.