TrailBlazer 4WD L6-4.2L VIN S (2002)
The inside rearview mirror will also darken the driver outside rearview mirror. The inside rearview mirror supplies a low reference circuit and a signal
circuit to the driver outside rearview mirror. Refer to Outside Mirror Description and Operation (Power Mirrors) or Outside Mirror Description and
Operation (Heated Mirrors) or Outside Mirror Description and Operation (Automatic Day - Night Mirrors) in Doors for further description and
operation of the driver outside rearview mirror.
COMPASS
The mirror uses two magnetic field sensors for compass direction. One sensor is for north and south, the other is for east and west. The mirror supplies
a signal and low reference to each sensor. As the vehicle travels with or against the earth's magnetic pull, there will be a change in voltage on one or
both sensors. As a result of the change in voltage, the mirror changes the heading on the compass display.
TEMPERATURE DISPLAY
The inside rearview mirror supplies a 5 volt signal circuit and low reference circuit to the ambient air temperature sensor. As the outside air
temperature gets warmer, the ambient air temperature sensor will pull the voltage lower on the 5 volt signal circuit. The inside rearview mirror
monitors this voltage and will show this as a warmer temperature on the display. Temperatures exceeding 112°C (143°F) will be out of the mirror's
temperature range which SC will be shown on the temperature display. In colder outside air temperatures, the ambient air temperature sensor will not
pull the voltage as low on the 5 volt signal circuit. The inside rearview mirror will show a colder temperature on the display. Temperatures exceeding
-40°C (-40°F) will be out of the mirror's temperature range which OC will be shown on the temperature display. In cold temperatures such as 3°C (37
°F) or below, the temperature display will show ICE when the ignition is first turned on. The display will toggle between ICE and the actual outside
temperature until the temperature update process is complete.
TEMPERATURE DISPLAY UPDATE PROCESS
The inside rearview mirror has a temperature program that takes in account the fact that the radiator will heat the ambient air temperature sensor if the
radiator is warm and the vehicle is not moving. If the vehicle has been off for more than 2 hours, the mirror temperature program assumes that the
radiator has cooled and that the temperature supplied by the ambient air temperature sensor is accurate. Because of this, if the vehicle has been off for
more than 2 hours, the mirror displays the temperature as reported by the ambient air temperature sensor. When the ambient air temperature sensor
reports a new temperature to the mirror, one of the following cases will apply:
^
Ignition is off for more than 2 hours, then is turned on for more than 3 minutes. The outside temperature is greater than the last temperature
recorded by the mirror for 2 minutes. The mirror will increase the last temperature reading by one degree every 2 minutes for 8 consecutive
times. If the outside temperature is not matched after the 8th update, the mirror will then display the current outside temperature.
^
Ignition is off for more than 2 hours, then is turned on for less than 3 minutes. The mirror will update the temperature display every 2 seconds.
^
Ignition is off for more than 2 hours, then is turned on for more than 3 minutes. The outside temperature is less than the last temperature recorded
by the mirror. The mirror will then display the current outside temperature.
^
Ignition has been off for less than 2 hours. The outside temperature is greater than the last temperature recorded by the mirror for 2 minutes. The
mirror will increase the last temperature reading by one degree every 2 minutes for the 8 consecutive times. If the outside temperature is not
matched after the 8th update, the mirror will then display the current outside temperature.
^
Ignition has been off for less than 2 hours. The outside temperature is greater than the last temperature recorded by the mirror, but the ignition is
cycled from on to off within 2 minutes. The mirror will display the old temperature.
^
Ignition has been off for less than 2 hours. The outside temperature is less than the last temperature recorded by the mirror. The mirror will then
display the current outside temperature.
SWITCHES OF THE INSIDE REARVIEW MIRROR WITH THE AUTOMATIC DAY-NIGHT FEATURE AND COMPASS WITHOUT
ONSTAR(R)
The inside rearview mirror has 2 switches that perform the following functions:
^
The MIRROR switch is used to enable or disable the automatic day-night feature of the mirror. With the ignition in the ON position, depress the
MIRROR switch to enable the automatic day-night feature of the mirror. A green indicator will illuminate on the mirror when the automatic
day-night feature is enabled. To disable the automatic day-night feature of the mirror, depress the MIRROR switch.
^
The COMPASS switch is used to turn the compass on and off. With the ignition in the ON position, depress the COMPASS switch to turn the
compass on. Depress the COMPASS switch again to turn the compass off. The COMPASS switch is also used to place the compass into a
calibration or zone mode. For more information, refer to Compass Calibration and Variance Procedure.
SWITCHES OF THE INSIDE REARVIEW MIRROR WITH THE AUTOMATIC DAY-NIGHT FEATURE, COMPASS/TEMPERATURE
DISPLAY WITHOUT ONSTAR(R)
The inside rearview mirror has two switches that perform the following functions:
^
The TEMP switch is used to turn the compass/temperature display on or off. It is also used to enable or disable the automatic day-night feature of
the mirror. With the ignition in the ON position, depress the TEMP switch to enable the compass/temperature display. Depress the TEMP switch
again to disable the compass/temperature display. The TEMP switch can be held for 4 seconds in order to change the display from Fahrenheit (°F)
to Celsius (°C), or from Celsius (°C) to Fahrenheit (°F). Depress the TEMP switch until the green indicator illuminates on the mirror. This
indicates that the automatic day-night feature is enabled. To disable the automatic day-night feature of the mirror, depress the TEMP switch until
the green indicator turns off.
^
The COMP switch is used to turn the compass/temperature display on or off. With the ignition in the ON position, depress the COMP switch to
turn the compass/temperature display on. Depress the COMP switch again to turn the compass/temperature display off. The COMP switch is also
used to place the compass into a calibration or zone mode. For more information, refer to Compass Calibration and Variance Procedure.
SWITCHES OF THE INSIDE REARVIEW MIRROR WITH THE AUTOMATIC DAY-NIGHT FEATURE WITH COMPASS AND
ONSTAR(R)
The inside rearview mirror has 4 switches that perform the following functions:
