Control Circuit Inspection

Check signal waveform
1. IG "OFF". Disconnect cooling fan module connector.
2. IG "ON".
3. Check to see if the PCM is controlling the cooling fan's PWM when the cooling fan is operating.
4. Is the measured signal waveform normal?
  YES
  - Substitute with a known - good cooling fan module and check for proper operation. If the problem is corrected, replace PCM and go to "VERIFICATION OF VEHICLE REPAIR PROCEDURE. "
  NO
  - Check to see if harness connected at the 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.