Signal Circuit Inspection

The inspection of ECTS signal line is for finding whether there is a open or short circuit in harness.

1. Check for open in harness
   1. Ignition "OFF"
   2. Disconnect ETC sensor connector.
   3. Ignition "ON" & Engine "OFF"
   4. Measure voltage between terminal 1 of sensor harness connector and chassis ground.

      Specification: approximately 5V

      Fig 1: Measuring Voltage Between Terminal 1 Of Sensor Harness Connector And Chassis Ground

      Courtesy of HYUNDAI MOTOR CO.
   5. Is measure voltage within Specification?

      YES 

      • Go to "Check for short to power in harness" below.

      NO 

      • In case over 5V: Short circuit to battery between ECTS harness connector and PCM harness connector.
      • In case 0V: Open circuit between ECTS harness connector and PCM harness connector.
      • Repair as necessary and then go to "VERIFICATION OF VEHICLE REPAIR " procedure
        NOTE: In case, when ECTS connector is disconnected, the voltage at terminal 1 is 0V.

        • Possible cause: Open or short between Terminal 1 of ETCS connector and terminal 39 of PCM.
2. Check for short to power in harness
   1. Ignition "OFF"
   2. Disconnect ECT sensor connector and PCM connector.
   3. Ignition "ON" & Engine "OFF"
   4. Measure resistance between terminal 1 and 3 of sensor harness connector.

      Specification: infinite

      Fig 2: Measuring Resistance Between Terminal 1 And 3 Of Sensor Harness Connector

      Courtesy of HYUNDAI MOTOR CO.
   5. Is measure resistance within Specification?

      YES 

      • Go to "GROUND CIRCUIT INSPECTION " procedure.

      NO 

      • Short circuit between cluster signal circuit and ECTS signal circuit.
      • Repair as necessary and then go to "VERIFICATION OF VEHICLE REPAIR " procedure

1. Ignition "OFF"
2. Disconnect ECT sensor connector.
3. Ignition "ON" & Engine "OFF"
4. Measure voltage or resistance between terminal 2 of sensor harness connector and chassis ground.

   Specification: below 0.5V or below 1Ω

   Fig 3: Measuring Resistance Between Terminal 2 Of Sensor Harness Connector And Chassis Ground

   Courtesy of HYUNDAI MOTOR CO.
5. Is measure voltage or resistance within Specification?

   YES 

   • Go to "COMPONENT INSPECTION " procedure.

   NO 

   • Open circuit between ECTS harness connector and PCM harness connector.
   • Open circuit between PCM harness connector and chassis ground.
   • Repair as necessary and then go to "VERIFICATION OF VEHICLE REPAIR " procedure
     NOTE: In case, when measuring resistance of ground circuit, the resistance is over 1 ohm.

     • Possible cause: Short circuit between PCM ground point and PCM terminal 35