2004-2005 Chevrolet Colorado and GMC Canyon - Inside Rear View Mirror Operation - Option DF8 and DC4 - keywords compass inoperative performance program rear temperature UE1 calibrate zone

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in the PI.

The owner's manual and eSI are incorrect in description and operation for the automatic dimming mirror with compass, temperature display and map lights. There are two mirrors available. They are DC4 and DF8. Below will describe how they are equipped and the functionality of both.

DC4 Mirror:

This mirror has a manual day/night dimming feature and no compass or temperature display. This mirror will also be used when equipped with OnStar (UE1) option.

DF8 Mirror:

This mirror has an auto day/night dimming feature and a display from compass and temperature. Below is an explanation to assist with the operation of the mirror.

There are only two switches on the front of the mirror and they are not labeled. They are used for turning the map lights on and off as well as turning the automatic dimming mirror on and off, calibrating the compass, turning the temperature and compass display on and off and changing the temperature from Fahrenheit to Celsius. There is no specific button, labeled "on/off" as the owner's manual and service information leads you to believe. Below is the correct function for each button on the mirror.

LEFT BUTTON

Action: Push and Release. Result: Turns Left Map lamp ON/OFF. Action: Push and Hold Approximately 4 seconds. Result: Turns Auto-Dimming feature OFF/ON. The Green LED indicates feature ON when lit. Action: Push and Hold Approximately 8 seconds. Result: Compass Calibration mode.

RIGHT BUTTON

Action: Push and Release Result: Turns Right Map lamp ON/OFF. Action: Push and Hold Approximately 4 seconds and release. Result: Changes Temperature Reading between °F, °C and NO Display. Repeat Hold to cycle to change display to next function. Action: Push and Hold Approximately 8 seconds and release Result: Compass Zone Change Mode: Push and hold button until "ZONE" appears in the display. Push same button repeatedly until the desired compass zone number is shown. The display will change back to the compass direction after three seconds if the button is not activated.

Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

(2004-2005 Chevrolet Colorado) and (2004-2005 GMC Canyon)