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 ECM when the cooling system operates.
  
  Fig 1: Checking Cooling Fan Module Signal Waveform
  Courtesy of KIA MOTORS AMERICA, INC.
  
  Fig 2: Cooling Fan Controller Connector End View
  Courtesy of KIA MOTORS AMERICA, INC.
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 ECM and then if the problem is corrected, replace ECM 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 ECM harness connector for open.
  - Repair or replace as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.