Circuit Description

PCM controls cooling fan low speed operation through the use of a low fan relay and a control circuit. If PCM commands fan low speed operation and senses fan did not turn on, or commands fan operation off and fan continues to run, DTC P0480 will be set.

Conditions required for setting DTC are:

• Ignition voltage is greater than 10 volts.
• Engine run time is greater than 32 seconds.

  Both previously listed conditions are met, and one of the following conditions are met for 25 seconds within a 50 second period:

• PCM senses voltage is high with low speed fan off.
• PCM senses voltage is low with low speed fan on.