P028DCharge Air Cooler Cooling Fan Control Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- 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. P028D means the fan's control circuit reads low – typically the control wire shorted to ground, detected by the driver stage. Depending on whether the module switches the low or the high side, the fan then runs permanently or not at all. No manufacturer document using this code was found; the description rests on CARB's output component requirement.
- What you may notice
- Warning light (manufacturer-dependent)
- Fan runs permanently or not at all
- Loss of power in heat possible
- Likely causes
- LikelyControl wire shorted to ground (chafing)
- PossibleRelay coil or fan module input shorted
- PossibleMoisture or corrosion in the connector
- RareDriver stage in the engine module faulty
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €30 – €300
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.