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Test "G" Ambient Temperature Sensor)

WARNING: This page is about a different car, the 1996 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.

  1. Check EATC System

    Test EATC system operation. See EATC SYSTEM TEST under TESTING. Repair as necessary. If system tests okay, go to next step.

  2. Check For Codes

    Turn ignition on. Enter self-diagnostics. See SELF-DIAGNOSTIC TEST. Record any codes or temperatures displayed. Exit self-diagnostics. If -40°F or 128°F is displayed and Code 040, 041, 042 or 043 is set, go to next step. If specified code and temperature are not displayed, go to step 4).
    NOTE: A temperature display of -40°F indicates sensor is open. A temperature display of 128°F indicates sensor is shorted.

  3. Check Sensor Resistance

    Disconnect negative battery cable to reset outside temperature display memory. Disconnect ambient temperature sensor connector. Measure resistance across sensor terminals. If resistance is as specified, go to next step. See AMBIENT TEMPERATURE SENSOR RESISTANCE table. If resistance is not as specified, replace sensor.
    AMBIENT TEMPERATURE SENSOR RESISTANCE

    Ambient Temp. °F (°C) Ohms
    50-68 (10-20) 37,000-58,000
    68-86 (20-30) 24,000-37,000
    86-104 (30-40) 16,000-24,000

  4. Check Voltage Input To Sensor

    Turn ignition on. Select AUTOMATIC mode. Disconnect ambient temperature sensor connector. Measure voltage at Red/Orange wire terminal of sensor connector. If voltage is approximately 5 volts, go to step 7). If voltage is not approximately 5 volts, go to next step.

  5. Check Output Voltage At EATC Module

    Measure voltage at terminal No. 1 (Red/Orange wire) of EATC module. If voltage is approximately 5 volts, go to next step. If voltage is not approximately 5 volts, replace EATC module (control panel).

  6. Check For Open Red/Orange Wire

    Turn ignition off. Connect jumper wire between known-good ground and Red/Orange wire terminal of sensor connector. Using ohmmeter, measure resistance between known-good ground and terminal No. 1 (Red/Orange wire) of EATC module connector. If resistance is 5 ohms or less, go to next step. If resistance is more than 5 ohms, repair open Red/Orange wire.

  7. Check For Open Pink/Black Wire

    Connect jumper wire between known-good ground and Pink/Black wire terminal of sensor connector. Using ohmmeter, measure resistance between known-good ground and terminal No. 2 (Pink/Black wire) of EATC module connector. If resistance is 5 ohms or less, replace sensor. If resistance is more than 5 ohms, repair open Pink/Black wire.
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