B0233Air Flow Control Circuit
- Generic OBD-II code · Body
- How the car detects it
- Public J2012 listings leave B0233 out, yet GM assigns it in its Global A climate control for the air distribution (mode) actuator. On 2011 Saab 9-5 and 9-4X cars that actuator is a stepper motor: the HVAC module feeds it a 12 V reference and switches its four coils to ground in pulses. B0233 01 means one of its control lines is shorted to voltage, B0233 06 that a line is open or low. The module tests the outputs only as the motor starts a move, not during travel or at the target. GM bulletin PIT5383 names B0233 among HVAC codes of 2015 models cured by reprogramming the K33 module. The rear distribution actuator reports B3531 instead. With the front actuator out, air keeps coming from the outlets last selected.
- What you may notice
- Air comes from the wrong outlets and the selected distribution is ignored
- Windscreen cannot be demisted because air will not switch to defrost
- Likely causes
- LikelyMode stepper actuator failed internally, e.g. a burnt coil or worn gear
- PossibleOne of the four control lines or the 12 V reference chafed, open or shorted behind the dash
- RareHVAC module software fault on affected GM models, fixed by reprogramming
- Repair
- Medium · Often possible to do yourself.Typical cost: €60 – €450
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.