Powertrain, generic · Auxiliary emission controls

P0481 Fan 2 Control Circuit

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

The engine module switches the radiator fan either through a relay, whose coil it pulls to ground, or with a PWM signal to a fan control module. The circuit is an output that CARB requires to be checked continuously. P0481 concerns the second fan control circuit – depending on the design a second fan or a second speed stage; on GM and Saab, relays 2 and 3 switch the fans in series or parallel for low and high speed. GM sets it for an open circuit (200 kΩ or more, 50 of 63 samples, MIL after two trips) and reports shorts as P0693/P0694. Ford's OBD summaries do not contain the code. One fan stage then fails or runs constantly; cooling usually remains partly available.

Likely causes

Fan relay 2 (or 2/3) faulty
Corrosion or water in relay or fan connector
Control wire open or shorted to ground
Driver in the engine module

Symptoms

  • Check engine light on
  • One fan stage or fan not working, or running constantly
  • Temperature rises at standstill

Repair estimate

DifficultyMediumDIY possible
Parts and labour€20–500
Time0.3–2 h

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

Parts involved

cooling fan 2fan relayengine control module

Related codes

P0480P0482P0483P0693P0694P0217

References: gsi.ext.gm.com, saabwisonline.com, saabwisonline.com.