P028F: Charge Air Cooler Cooling Fan Control Circuit Driver Performance

What does P028F mean?

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. P028F concerns the driver stage that switches the fan: it reports an internal fault such as overcurrent or overheating, or its diagnosis does not match the command. A shorted fan motor or wiring can overload the driver; otherwise the driver in the engine or fan module is faulty. No manufacturer document using this code was found; the description rests on CARB's output component requirement.

The code tells you which monitor failed, not which part is broken. Test before replacing parts.

Symptoms

• Warning light (manufacturer-dependent)
• Loss of power in heat or at low speed
• High charge air temperature, possibly P026A

Common causes

• High Fan motor or wiring shorted (driver overload)
• Medium Driver in the engine or fan module faulty
• Low Supply voltage or ground of the module poor

Likelihood is a general estimate across vehicles; your make and model may differ.