Signal Circuit Inspection

Check Reference Voltage to IAT Sensor 

1. IG KEY: OFF, Engine: OFF
2. Disconnect IAT sensor connector (B-29).
3. IG KEY: ON, Engine: OFF
4. Measure voltage between terminal 1 of the IAT sensor harness connector B-29 and chassis ground.
   1. Specification: approx. 5V
      Fig 1: Measuring Voltage Between Terminal 1 Of IAT Sensor Harness Connector B-29 And Chassis Ground

      
5. Is the voltage near the specified value?

   YES

   1. Go to "COMPONENT INSPECTION " procedure.

   NO

   1. Possibility of signal circuit malfunction.
   2. Go to "Check for Short to Ground in Harness" procedure.

Check for Short to Ground in Harness 

1. IG KEY: OFF, Engine: OFF
2. Disconnect IAT sensor connector (B-29).
3. Measure resistance between terminal 1 of the IAT sensor harness connector B-29 and chassis ground.
   1. Specification: infinite (infinite Ω)
      Fig 2: Measuring Resistance Between Terminal 1 Of IAT Sensor Harness Connector B-29 And Chassis Ground

      
4. Is the resistance near the specified value?

   YES

   1. Go to "COMPONENT INSPECTION " procedure.

   NO

   1. Repair as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.