P028CCharge Air Cooler Cooling Fan Stuck On
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Needs a drive cycle to confirm a fix
- How the car detects it
- Some vehicles – mainly commercial and off-road machines, or cars with a separate cooler for a coolant-cooled charge air cooler – have their own fan for the charge air cooler, switched by the engine module; a Deere patent describes such a fan that is also reversed to blow out dirt. P028C means the fan runs although the module has switched it off – speed or current feedback, or the voltage at the output, does not match the off command. Typical causes are a welded relay contact or a shorted driver stage. The fan runs continuously and can drain the battery; the charge air tends to be too cold, which favours condensate. No manufacturer document using this code was found; the description rests on CARB's output component requirement.
- What you may notice
- Fan runs all the time, even after switch-off
- Battery drains
- Warning light (manufacturer-dependent)
- Likely causes
- LikelyRelay contact welded
- PossibleDriver stage or fan control module shorted
- PossibleControl wire shorted (to ground on low-side, to voltage on high-side control)
- Repair
- Easy · Often possible to do yourself.Typical cost: €20 – €300
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.