Outside Air Temperature Display Inaccurate or Inoperative

Outside Air Temperature Display Inaccurate or Inoperative

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview

Circuit/System Description

The driver information center (DIC) applies 5 volts to the ambient air temperature sensor. The ambient air temperature sensor is a thermistor which varies in resistance as the temperature changes. As the resistance of the ambient air temperature sensor increases, the DIC senses a larger voltage drop across the sensor indicating a lower temperature. As the resistance of the ambient air temperature sensor decreases, the DIC senses a smaller voltage drop across the sensor indicating a higher temperature.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector of the ambient air temperature sensor. Install a signal generator and instrument panel tester between the signal circuit and the low reference circuit.
2. Ignition ON, vary the resistance on the signal generator from 600-97,000 ohms. Refer to Sensor Resistance Table (Evaporator Temperature) Sensor Resistance Table (Outside Air Temperature). Verify that the temperature displayed on the DIC matches the resistance values in the Sensor Resistance Table.

• If the temperature is incorrect, test the signal circuit and the low reference circuit for an open/high resistance. If the circuit tests normal, replace the IPC.

3. If all circuits test normal, test or replace the ambient temperature sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

* Ambient Air Temperature Sensor Replacement
* Programming and Relearning for the IPC setup, and programming. Programming and Relearning