Component Inspection

Measuring the resistance of IAT sensor is to find whether the open circuit exists in the sensor's inner side.

1. Measure resistance between terminal 3 and 4 of sensor connector (To sensor side)

   Specification: 20°C (68°F): 2.0~3.0kΩ, 80°C (176°F): 0.2~0.4kΩ

   Fig 1: Measuring Resistance Between Terminal 3 And 4 Of Sensor Connector

   Courtesy of HYUNDAI MOTOR CO.
2. Does each resistance indicate continuity circuit?

   YES 

   • Go to "Check PCM" below.

   NO 

   • Open circuit IATS.
   • Repair as necessary and then go to "VERIFICATION OF VEHICLE REPAIR " procedure
     NOTE: The purpose to measure IAT resistance is to decide where open circuit exists and the method is to check continuity between IAT signal line and ground line.

The purpose of checking ECM is to determine whether there is any malfunction of PCM.

1. Ignition "OFF"
2. Connect scan tool and Engine "ON "
3. Select simulation function on scan tool.
4. Simulate voltage at terminal 3 of IAT sensor signal connector
5. Verify IATS voltage to change while raising or lowering simulation voltage with scan tool within 0.5~3.5 V

   Specification: If the data is changeable as simulation voltage changes, it's OK

   Fig 2: Identifying Scan Tool Display (Simulate Voltage)

   Courtesy of HYUNDAI MOTOR CO.
6. Is IAT sensor signal value changed according to simulation voltage ?

   YES 

   • Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.

   NO 

   • Substitute with a known-good PCM and check for proper operation. If the problem is corrected, replace PCM and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.