Signal Circuit Inspection

■ Check Short to Battery in Harness 

1. Ignition "OFF"
2. Disconnect Auto Defog sensor and A/C control unit main harness connector.
3. Ignition "ON"
4. Measure voltage between Signal terminal of Auto Defog sensor harness connector and chassis ground.

   Specification  : approx. 0V

   Fig 1: Measuring Voltage Between Auto Defog Sensor Harness Connector And Chassis Ground

   Courtesy of HYUNDAI MOTOR AMERICA
5. Is the measured voltage within specification?

   YES 

   • Go to "Check for Open in Harness " as follows.

   NO 

   • Check for open in harness.
   • Repair as necessary and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.

■ Check for Open in Harness 

1. Ignition "OFF"
2. Disconnect Auto Defog sensor and A/C Control unit main harness connector.
3. Measure resistance between Sensor Signal terminal of Auto Defog sensor harness connector and Sensor Signal terminal of A/C-ECU harness connector.

   Specification  : 1 below

   Fig 2: Measuring Resistance Between Auto Defog Sensor Harness Connector And A/CECU Harness Connector

   Courtesy of HYUNDAI MOTOR AMERICA
4. Is the measured resistance within specification?

   YES 

   • Go to "COMPONENT INSPECTION " procedure.

   NO 

   • Check for open in harness.
   • Repair as necessary and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.