GM Service Manual Online
For 1990-2009 cars only

Important: The following DTCs: U1000, U1064, U1016 are communication codes. Refer to Diagnostic Trouble Code (DTC) List in Data Link Communications. To change the temperature display from degrees Fahrenheit to degrees Celsius, press the AUTO, ECON and MODE buttons simultaneously for 3 to 5 seconds.

The following table lists Automatic Climate Control Module Diagnosis Codes related to the Automatic Climate Control.

Defrost Data

Auto Switch Actual

High/Low

Off Switch Actual

High/Low

Economy Switch Actual

High/Low

Fan Speed

Counts

Outside Air Temp

Counts

Inside Air Temp

Counts

Sunload Sensor

Counts

Defrost Switch Command

On/Off

Defrost Switch Actual

On/Off

Defrost LED

On/Off

Rear Defrost Switch Command

On/Off

Rear Defrost Switch Actual

On/Off

Rear Defrost LED

On/Off

Rear Defrost Feedback

High/Low

Actuator Data

Auto Switch Actual

High/Low

Off Switch Actual

High/Low

Economy Switch Actual

High/Low

Fan Speed

Counts

Outside Air Temp

Counts

Inside Air Temp

Counts

Sunload Sensor

Counts

Auto Switch Command

On/Off

Off Switch Command

On/Off

Economy Switch Command

On/Off

Mode Switch Command

On/Off

Mode Switch Actual

High/Low

Recirc Switch Command

1=Off

0=On

Recirc Switch Actual

High/Low

Recirc LED

On/Off

Mode Feedback

Counts

Mix Feedback

Counts