A typical diagnosis is IAT Sensor Short to Ground.
87.2.1
Intake Air Temperature Sensor Short to Ground Check
Perform the following steps to troubleshoot an IAT Sensor short to ground fault:
1. Disconnect the IAT Sensor.
2. Disconnect the 120–pin MCM connector.
3. Measure the resistance across pins 1 and 2 of the IAT Sensor connector.
[a] If the resistance is less than 5k Ω, repair the short between wires 52 and 106 of the
120–pin MCM Connector. Refer to section 87.2.1.1.
[b] If the resistance is greater than 5k Ω, go to step 4.
4. Measure the resistance between pin 2 of the sensor harness connector and ground.
[a] If the resistance is less than 5 Ω, repair the short circuit between pin 2 of the sensor
harness connector and ground. Refer to section 87.2.1.1.
[b] If the resistance is greater than 5 Ω, refer to section 87.2.1.1.
