Outside Air Temperature Display Inaccurate or Inoperative

Outside Air Temperature Display Inaccurate or Inoperative

Diagnostic Fault Information

Important: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview

Circuit/System Description

The outside air temperature sensor is a variable resistor interfaced to the driver information center (DIC) via the outside air temperature sensor signal circuit and low reference circuit. The DIC provides the logic for reading the outside air temperature sensor, filtering the data and displaying the outside air temperature. A warmer outside air temperature results in a lower outside air temperature sensor resistance. Temperature reading exceeding 62°C (143°F) is out of the DIC temperature range and will not be displayed. When the temperature reading exceeds 62°C (143°F), "SC" is displayed in the DIC. A colder outside air temperature results in a higher outside air temperature sensor resistance. Temperature reading lower than -40°C (-40°F) is out of the DIC temperature range and will not be displayed. When the temperature reading is lower than -40°C (-40°F), "OC" is displayed in the DIC. In colder temperatures such as 3°C (37°F) or below, the mirror displays "ICE" when the ignition is first turned on. The DIC temperature display toggles between "ICE" and the actual outside temperature until the temperature update process is complete. If the outside air temperature sensor is opened or shorted, the temperature displayed is either a cold or hot extreme. An open ambient air temperature sensor displays as "OC" and an outside air temperature sensor shorted to ground displays as "SC".

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the ambient air temperature sensor.
2. Ignition OFF, test for less than 1 ohm of resistance between the low reference circuit and ground.

• If greater than 1 ohm, test the low reference circuit for an open/high resistance.

3. Ignition ON, verify the DIC displays "OC".

• If the DIC does not display "OC", test the outside air temperature sensor signal circuit for a short to ground. If the circuit tests normal, replace the DIC.

4. Ignition ON, install a 3 amp fused jumper wire between the signal circuit and the low reference circuit of the outside air temperature sensor. Verify the DIC displays "SC".

• If the DIC does not display "SC", test the signal circuit of the outside air temperature sensor for a short to voltage or an open/high resistance. If the circuit tests normal, replace the DIC.

5. If all circuits test normal, test or replace the outside air temperature sensor.

Repair Instructions

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

* Ambient Air Temperature Gage Sensor Replacement
* Programming and RelearningProgramming and Relearning