Circuit/System Testing: P0097

With the ignition ON, the engine OFF, and the IAT sensor 2 disconnected, observe the IAT Sensor 2 parameter with a scan tool for a value of less than -39°C (-38°F).

• If the IAT Sensor 2 parameter is less than -39°C (-38°F), replace the IAT sensor 2.
• If the IAT Sensor 2 parameter is more than -39°C (-38°F), test the IAT sensor 2 signal circuit for a short to ground, low reference, or faulty ECM.

P0098

1. With the ignition ON, the engine OFF, and the IAT sensor 2 disconnected, measure the voltage between the IAT sensor 2 signal circuit and a good ground with a DMM.
   • If the voltage is more than 5.1 volts, test the IAT sensor 2 signal circuit for a short to voltage.
   • If the voltage is less than 4.8 volts, test the IAT sensor 2 signal circuit for an open or a faulty ECM.
2. Measure the voltage between the IAT sensor 2 low reference circuit and the IAT sensor 2 signal circuit.
   • If the voltage is less than 4.8 volts, test the ECT low reference circuit for an open, or a faulty ECM.
   • If the voltage is between 4.8-5.1 volts, test the IAT 2 signal and low reference circuits for high resistance.
3. With the ignition ON, engine OFF, and the IAT sensor harness disconnected, observe the scan tool IAT temperature parameter for a value of less than -39°C (-38°F). With the 3-amp fused jumper wire connected between the signal and low reference circuits, observe the scan tool IAT temperature parameter for a value of more than 148°C (298°F).
   • If the temperature is more than 148°C (298°F), test the IAT signal circuit for a short to a 5-volt reference circuit.
   • If the IAT sensor 2 circuits test normal, replace the IAT sensor.