Signal Circuit Inspection

Check reference voltage in harness.
1. Ignition "OFF".
2. Disconnect IAT sensor connector.
3. Ignition "ON" & Engine "OFF".
4. Measure voltage between terminal 5 of IAT sensor harness connector and chassis ground.
  Specification: Approx. 5V
  
  Fig 1: Measuring Voltage Between Terminal 5 Of IAT Sensor Harness Connector And Chassis Ground
5. Is the measured voltage within specifications?
  YES
  - Go to "COMPONENT INSPECTION " procedure.
  NO
  - Go to " 2 Check for short to ground in harness" as below.
Check for short to ground in harness.
1. Ignition "OFF".
2. Disconnect IAT sensor connector and PCM connector.
3. Measure resistance between terminal 5 of IAT sensor harness connector and chassis ground.
  Specification: Infinite
  
  Fig 2: Measuring Resistance Between Terminal 5 Of IAT Sensor Harness Connector And Chassis Ground
4. Is the measured resistance within specifications?
  YES
  - Go to "COMPONENT INSPECTION " procedure.
  NO
  - Check for short to ground in signal harness.
  - Repair or replace as necessary. And then, go to "VERIFICATION OF VEHICLE REPAIR " procedure.