U350DControl Module Cooling Fan Circuit Low
- Generic OBD-II code · Network
- Can trigger limp mode
- How the car detects it
- U350D is set when the voltage or current feedback in a control module's fan circuit sits below the window the module expects. Usually the fan supply or control wire touches ground, or the motor itself has shorted turns, so the output stage limits current or switches off and the fan stands still; a blown fan fuse produces the same picture. Electronics with a dedicated fan exist, for example the charger of the 2021 Toyota RAV4 Prime with its fan speed sensor (T-SB-0021-21), and CARB demands that electrical outputs cooling inverters and batteries be checked for circuit faults. No manufacturer publishes U350D. Once warm, the module will most likely protect itself by lowering its output. An open circuit is U350C, a short to voltage U350E.
- What you may notice
- Module fan does not run
- Reduced function or shutdown of the module when hot
- Blown fan fuse
- Likely causes
- LikelyFan supply or control wire chafed through to ground
- PossibleFan motor with shorted windings drawing excess current
- PossibleFan fuse blown as a result of the short
- RareOutput stage in the module pulling the line low
- Repair
- Medium · Usually a job for a workshop.Typical cost: €30 – €500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.