OBD-II code · Powertrain (generic, extended)
P239B Diesel Intake Air Flow B Control Motor Current Range or Performance
The motor current of the actuator on diesel intake air flow B is outside the calibrated window - typically excessive (sticky valve), or too low (worn brushes).
Is it safe to drive with P239B?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyMotor overloaded by jammed valve
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 1–4 h
- Emissions test
- Likely to fail
- Parts involved
- Diesel Intake Air Flow B
Related codes
- P2398Diesel Intake Air Flow B Position Sensor Circuit Low
- P2399Diesel Intake Air Flow B Position Sensor Circuit High
- P239ADiesel Intake Air Flow B Position Sensor Circuit Intermittent or Erratic
- P239CDiesel Intake Air Flow B Control System High Air Flow Detected
- P239DDiesel Intake Air Flow B Control System Low Air Flow Detected
- P239EO2 Sensor Out of Range During Deceleration Bank 1 Sensor 2
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.