Control Circuit Inspection

■ Check signal waveform 

1. IG "OFF" and disconnect Cooling fan module connector.
2. IG "ON".
3. Check if the cooling fan is controlled in the way of PWM control by PCM when the cooling system operates.
4. Is the measured signal waveform normal?

   YES 

   • If the problem is corrected after substituting with a known - good Cooling Fan module, replace it. If the problem is pending, check for proper operating after substituting with a known - good PCM and then if the problem is corrected, replace PCM and go to "VERIFICATION OF VEHICLE REPAIR " procedure.

   NO 

   • Check that harness connected at engine compartment junction block is disconnected or not.
   • Check the line between control terminal of Cooling Fan module harness connector and cooling fan control terminal of PCM harness connector for open.
   • Repair or replace as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.