Power Mirrors System Components
• | Outside rear view mirror switch |
• | Memory mirror module (w/A45) |
Outside Power Mirror Operation (w/o A45)
Each outside power mirror has 2 reversible motors. One motor adjusts
the mirror view left and right - horizontal, the other motor adjusts
the mirror up and down - vertical. The driver selects which mirror
is moved by placing the mirror select switch in either the L or R position.
The driver then operates the mirror switch in one of the following positions
in order to control the polarity of the battery voltage applied to the
mirrors:
Battery positive voltage is applied from the underhood fuse block MIRROR
fuse (10A) to either the left or right power mirror. As the mirror switch
is operated, battery voltage and ground is supplied through the contacts
of the switch.
Outside Power Mirror Operation (w/A45)
The memory mirror module (MMM) controls the memory mirrors by controlling
the movement of the mirror motors. The LH mirror and the RH mirror each
have 1 motor for Up or Down movements, and 1 motor for Left or Right movements.
All of the motors operate independently of each other. Each motor has an
attached position sensor.
The underhood fuse block MIRROR fuse (10A) supplies battery positive
voltage to power the MMM and the mirror motors.
Mirror Position Sensor Operation
The position sensors are used by the MMM in order to perform the following
functions:
• | Store the motor positions in memory. |
• | Return the motors to the stored memory positions. |
The mirror position sensors are potentiometers that are mounted to
each mirror motor's transmission cable. When the cable rotates, the resistance
of the potentiometer varies. The feedback voltage is monitored by the
MMM in order to determine the motor position. The sensor feedback voltages
vary from 0.25-4.75 volts. When a set memory command is
executed, the MMM records and stores the motor positions by recording each
position sensors feedback voltage. When a memory recall is commanded,
the MMM moves the motors until all of the position sensor feedback voltages
equal the voltages stored in the memory.
Memory Set Operation
When the MMM receives inputs from the memory set switches, the MMM
records the feedback voltages from the 4 mirror position sensors for the
appropriate driver. The MMM sends a Class 2 message to the memory
seat module (MSM). This action informs the module of the SET MEMORY command.
Memory Recall Operation
The MMM applies the battery positive voltage to the mirror motors until
all of the mirror position sensor feedback voltages equal the feedback
voltages stored in memory for the appropriate driver. The MMM also commands
the MSM to perform the memory recall function via a Class 2 message.
The MSM then applies the battery positive voltage (B+) to all of
the seat and lumbar support motors until the position sensor feedback
voltages equal the feedback voltages stored in the memory for the
appropriate driver.
Heated Mirrors Operation
When the rear defogger is turned ON, the instrument cluster (IPC) confirms
that the engine is running. The IPC receives engine status from the powertrain
control module (PCM) via the class 2 serial data line. When engine
status has been confirmed, the IPC turns ON the rear defogger-ON LED and
commands the body control module (BCM) to turn ON the rear defogger relay
via the class 2 serial data line. When the BCM grounds the rear defogger
relay coil, the relay energizes applying battery positive voltage to the
HTD MIR Fuse (10A). The HTD MIR Fuse provides battery positive voltage to
the heated mirrors.
Automatic Day/Night Feature Operation
The automatic day/night feature of the driver outside rearview mirror
is controlled by the inside rearview mirror. The inside rearview mirror supplies
a signal and a low reference to the driver outside rearview mirror.
The voltage on the signal circuit of the driver outside rearview mirror
varies between 0.5 to 1.5 volts depending on light conditions
present at the inside rearview mirror. At night, with the automatic
day-night feature enabled, the driver outside rearview mirror will
automatically darken with the inside rearview mirror to reduce the glare
from the headlamps from behind. The voltage on the signal circuit of
the driver outside rearview mirror will be near 1.5 volts. In
the daytime, the mirrors are in a normal state. The voltage on the signal
circuit of the driver outside rearview mirror may be less than or near
0.5 volts. Refer to
Automatic Day-Night Mirror Description and Operation
in Stationary Windows for further description and operation of the inside
rearview mirror.