Powertrain, generic · Fuel and air metering (injector circuit)

P028C Charge Air Cooler Cooling Fan Stuck On

Check engine lightOn
EmissionsNot relevant
Drive cycleRequired
Limp modeNo

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.

Likely causes

Relay contact welded
Driver stage or fan control module shorted
Control wire shorted (to ground on low-side, to voltage on high-side control)

Symptoms

  • Fan runs all the time, even after switch-off
  • Battery drains
  • Warning light (manufacturer-dependent)

Repair estimate

DifficultyEasyDIY possible
Parts and labour€20–300
Time0.3–1.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

charge air cooler fanfan relayfan wiring

Related codes

P028AP028BP028DP028EP028FP026A

References: law.cornell.edu, patents.google.com.