Inside Rearview Mirror with the Automatic Day-Night Feature System
Components
The inside rearview mirror with the automatic day-night feature system
consist of the following components:
| • | Ambient air temperature sensor |
Inside Rearview Mirror with the Automatic Day-Night Feature System
Operation
With the ignition switch in the ON position, ignition 1 voltage
is supplied through the IGN 1 fuse to the inside rearview mirror.
The inside rearview mirror uses 2 photocell sensors in
order to determine light conditions in the front and the back
of the vehicle. At night, with automatic day-night feature enable,
the mirror automatically darkens to reduce the glare from the headlamps
from behind. In the daytime, the mirror is in a normal state.
With the gear selector lever in the REVERSE position, backup
lamp supply voltage is supplied as an input to the inside rearview
mirror. The automatic day-night mirror will gradually change to
a normal state as a result of the backup lamp supply voltage
input. Ground for the inside rearview mirror is provided by G203.
Temperature Display
The inside rearview mirror supplies a 5 volt signal circuit and
low reference circuit to the ambient air temperature sensor. The inside rearview
mirror monitors and records the voltage on the signal circuit of
the ambient air temperature sensor. The inside rearview mirror uses
this recorded voltage to display the temperature on the temperature
display portion of the compass/temperature display. The temperature
display will show "ICE" when the ignition is first
turned on and the current temperature is 3°C (37°F)
or below. The display will toggle between "ICE" and
the actual outside temperature for approximately 4 minutes.
The mirror will display "OC" if the mirror senses a temperature
of less than -40°C (-40°F).
the mirror will display a "SC" if the mirror senses a temperature
of greater than 112°C (143°F ).
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. |
Compass
The electronic compass includes a magnetic field sensor and a microprocessor.
The microprocessor receives inputs from the sensor, processes these
inputs, and provides a heading on the compass/temperature display.
Switches of the Inside Rearview Mirror with the Automatic Day-Night
Feature, Compass, and Temperature Display
The inside rearview mirror has two switches that perform the following
functions:
| • | The TEMP switch is used to enable or disable the temperature display
and the automatic day-night feature of the mirror. With the ignition in the
ON position, depress the TEMP switch to enable the temperature display.
Depress the TEMP switch again to disable the temperature display.
The TEMP switch can be held for 8 seconds in order to change the
display from Fahrenheit (°F) to Celsius (°C), or from Celsius
(°C) to Fahrenheit (°F). Depress the TEMP switch for
15 seconds 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 TEMP switch
for 15 seconds. |
| • | The COMP switch is used to turn the compass on and off. With the
ignition in the ON position, depress the COMP switch to turn the compass
on. Depress the COMP switch again to turn the compass 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 Magnetic Variance
. |
