B0252Driver Window Motor Down Circuit
- Generic OBD-II code · Body
- How the car detects it
- For B0252 there is neither a J2012 entry nor any factory description, so the code is unverified. The title names one direction of the driver's window motor. A reversible DC motor moves the glass; the down path is the half of the drive that puts supply on one motor terminal and ground on the other. In patent US6906487B2 (International Rectifier, now Infineon) two smart high-side switches and two low-side MOSFETs form that H-bridge, read the motor current and shut down on shorts or overheating. If only the down path fails, the window still closes but will not open, which points to one driver stage, a relay contact or one motor lead. Pinch protection under FMVSS 118 reverses the glass downwards, so a dead down path disables it as well.
- What you may notice
- Driver's window closes but will not go down
- Pinch protection or one-touch down no longer works
- Likely causes
- LikelyDown relay contact or driver transistor in the door module burnt
- PossibleOne motor lead broken in the door or at the motor plug
- RareWorn motor brushes or commutator with a dead spot in one direction
- Repair
- Medium · Often possible to do yourself.Typical cost: €80 – €500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.