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

P028B Charge Air Cooler Cooling Fan Performance/Stuck Off

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

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. P028B means the module commands the fan on but sees no effect – no speed or current feedback from a fan control module, or the charge air does not cool – although the circuit is electrically sound (circuit faults are P028A, P028D and P028E). The charge air then gets hotter, which can limit boost and power. No manufacturer document using this code was found; the description rests on CARB's output component requirement.

Likely causes

Fan motor seized or worn
Fan blocked (debris, dirt, ice)
Fan relay or fan control module without output
Fan fuse or supply

Symptoms

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

Repair estimate

DifficultyMediumDIY possible
Parts and labour€80–500
Time0.5–2 h

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

Parts involved

charge air cooler fanfan relayfan wiring

Related codes

P028AP028CP028DP028EP028FP026A

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