Using ATC Control Panel

ATC fault codes can only be retrieved from ATC control panel when engine is running and vehicle is not moving. Set parking brake and place transmission in Park position. Start engine and ensure vehicle does not move. Set ATC control panel temperature to 75°F so that any displayed 2-digit DTC will not be confused with temperature display.
NOTE: It is important that no other ATC control panel knob, button or switch is actuated (except panel mode button) until all ATC DTCs are displayed. Pushing any ATC control panel knob, button or switch (except panel mode button) will end diagnostic mode, ATC fault codes will not be displayed and system will return to normal operation ("F" or "C" displayed on ATC control panel).
Simultaneously press and hold floor, mix, and defrost buttons at ATC control panel. See Figure. Release buttons when ATC control panel display begins to blink, indicating ATC system has entered calibration/diagnostic mode. ATC control panel display will continue to blink until actuator door calibration and fault code check are completed.
If ATC system is okay and there are no stored DTCs, system will return to normal operation and temperature symbol "F" or "C" will be displayed. If there is a stored ATC DTC, a two-digit code will be displayed on ATC control panel window. See IDENTIFYING ATC DIAGNOSTIC TROUBLE CODES table. If more than one ATC DTC is stored in memory, it will be necessary to scroll through and record all ATC DTCs. To view each code after diagnostic mode is completed, depress panel mode button on ATC control panel.
To scroll through additional DTCs stored, press panel mode button on ATC control panel until all DTCs have been cycled through display window of ATC control panel. To identify DTC fault message associated with 2-digit ATC codes displayed, see IDENTIFYING ATC DIAGNOSTIC TROUBLE CODES table. Perform appropriate test procedure for ATC DTCs displayed. See DTC/FAULT MESSAGE DIAGNOSTIC TESTS table under DIAGNOSTIC TESTS.
To exit calibration/diagnostic mode, turn ignition switch to OFF position. To clear ATC DTCs, see CLEARING DIAGNOSTIC TROUBLE CODES .

NOTE: ATC DTC 26 will be stored if in-car temperature sensor is disconnected, BCM connectors are disconnected and/or ATC control panel connectors are disconnected (even with ignition off). If ATC DTC 26 is set, clear ATC DTC 26 from memory. See CLEARING DIAGNOSTIC TROUBLE CODES . Check ATC operation, test drive vehicle and attempt to reset ATC DTC 26. If ATC DTC 26 resets, continue with diagnostics.

IDENTIFYING ATC DIAGNOSTIC TROUBLE CODES

Code ⁽¹⁾

ATC DTC Description

Go To Diagnostic Test

Blend Door Feedback Failure

Mode Door Feedback Failure

Ambient Temperature Sensor Failure

⁽²⁾

In-Car Temperature Sensor/Aspirator Failure

Sun Load Sensor Failure

Recirculation Door Actuator Stall Test Failure

Blend Door Actuator Stall Test Failure

Mode Door Actuator Stall Test Failure

Engine Temperature Message Not Received

⁽³⁾

Evaporator Temperature Sensor Failure

ATC Control Panel Communication Failure

⁽²⁾

Blend Door Actuator Output Shorted To Battery

Blend Door Actuator Output Shorted To Ground

Mode Door Actuator Output Shorted To Battery

Mode Door Actuator Output Shorted To Ground

Recirculation Door Actuator Output Shorted To Battery

Recirculation Door Actuator Output Shorted To Ground

Common Door Output Shorted To Battery

Common Door Output Shorted To Ground

System Voltage Too Low For Door Calibration

⁽⁴⁾

⁽¹⁾	Code retrieved from Automatic Temperature Control (ATC) control panel.

⁽²⁾	See appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.

⁽³⁾	See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.

⁽⁴⁾	Diagnose concern with vehicle battery or charging system. See appropriate STARTING & CHARGING SYSTEMS article in ACCESSORIES & EQUIPMENT.