Control Circuit Inspection

Check signal waveform

IG "OFF" and disconnect Cooling fan module connector.
IG "ON".
Check if the cooling fan is controlled in the way of PWM control by ECM when the cooling system operates.

Fig 1: Check Signal Waveform Of Cooling Fan Controller
Courtesy of HYUNDAI MOTOR CO.

Fig 2: Identifying ECM Connector Terminals
Courtesy of HYUNDAI MOTOR CO.
Is the measured voltage within specifications?
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 open or short in control circuit, and go to "VERIFICATION OF VEHICLE REPAIR " procedure.