A/C Ambient Air Temperature Sensor Diagnosis

Condition(s):

- On-Board Diagnostics DTC 04 and Outside Temperature Display is Reading 40°F (-40°C) or 140°F (60°C) (Warm Air Discharge at 65°F (18°C) or Cool Air Discharge at 86°F (30°C)

Possible Source(s):

- A/C ambient air temperature sensor and bracket open or shorted.

Action(s) to Take:

- Disconnect battery cables (necessary to reset outside temperature display memory). Disconnect wire harness connector at A/C ambient air temperature sensor and bracket. Measure resistance across A/C ambient air temperature sensor and bracket terminal and compare with automatic temperature control Sensor Resistance Table. If resistance is out of specifications, replace A/C ambient air temperature sensor and bracket. If A/C ambient air temperature sensor and bracket is OK, proceed to "A/C ambient air temperature sensor and bracket wire harness open or shorted". Reconnect battery cables.

NOTE: Install A/C ambient air temperature sensor and bracket and electrical connections before battery is reconnected.

Condition(s):

- Intermittent Heating and Cooling. Outside Temperature Display sometimes inaccurate

Possible Source(s):

- A/C ambient air temperature sensor and bracket wire harness open or shorted.

Action(s) to Take:

- Disconnect battery cables. Disconnect wire harness connector from A/C ambient air temperature sensor and bracket and disconnect both connectors from the EATC control assembly. Check for continuity and for possible shorting between two wires (Pin 1 and Pin 2). Service as necessary. Reconnect wire harness and battery cables.