als Module (MSMAPM) is located under the driver’s
seat. It receives input from the following: driver’s
manual 8-way seat switch, driver’s seat position
sensors, PCI bus circuits, and the power mirror
sensors. The module uses these inputs to perform
the following functions: position the driver’s mem-
ory seat, both exterior mirrors (during recalls), both
pedals, and send/receive the memory system infor-
mation over the PCI bus.
The Memory Set Switch is wired to the Body
Control Module (BCM). A button (either #1 or #2)
pressed on the set switch causes the BCM to send a
message to the MSMAPM which in turn will send a
motion status message back to the BCM. If the
message from the MSMAPM indicates no current
motion, the BCM will send a recal message to the
module. The MSMAPM will set the seat, exterior
mirror, pedals, and radio to the presets for the
indicated driver.
If any one of the memory controlled systems is
inoperative from its manual switch, use the sche-
matics and diagnostic information to correct the
concern. This manual addresses the memory prob-
lems only and it is assumed there is not a basic
component failure.
3.14.1
POWER SEAT
The memory power seat provides the driver with
2 position settings for the driver’s seat. Each power
seat motor is connected to the MSMAPM with two
motor drive circuits. Each circuit is switched be-
tween battery and ground. By being able to bi-
directionally drive the circuits, the MSMAPM con-
trols the movement of the motors based on input
from the power seat switch or from the position
sensors when performing a memory recall. Each
motor contains a potentiometer to monitor the seat
position. To monitor the position of the motor, the
MSMAPM sends out a 5-volt reference on the sen-
sor supply circuit. The sensor is grounded back to
the module on a common ground circuit. Based on
the position of the sensor, the MSMAPM monitors
the voltage change through the sensor on a separate
signal circuit.
The MSMAPM stores the input value of each of
the four seat potentiometers in memory when the
system requests a set. The driver can initiate a
memory recall, using either the door mounted mem-
ory switch or the RKE transmitter (if the remote
linked to memory feature is enabled via the EVIC).
When initiated, the MSMAPM adjusts the four seat
sensors (by using the motors) to match the memo-
rized seat position data.
For safety, the memory seat recall is disabled by
the MSMAPM when the vehicle is out of park
position or if the speed is not zero. Any obstruction
to seat movement over a 2-second delay will cause
the seat to stop moving in which case a stalled
motor would be detected by the MSMAPM and the
corresponding seat output would be deactivated.
However, if the object obstructing the seat is re-
moved, the seat will function normally again.
3.14.2
MEMORY MIRROR
The driver sideview mirror contains vertical and
horizontal bi-directional drive positioning motors
and position sensors. The MSMAPM provides a
5-volt reference on the signal circuit to each position
sensor. The sensors share a common ground circuit.
The MSMAPM monitors the position of the mirror
motors by measuring the voltage on each signal
circuit. When a memory position is set, the MS-
MAPM monitors and stores the position of the
outside mirror. The MSMAPM adjusts the mirror to
the appropriate positions when a memory recall
message is received from the RKE or is requested
from the memory set switch.
The power mirror switch during non-memory
operation operates the mirror independently of the
MSMAPM.
3.15
OVERHEAD CONSOLE
COMPASS/TEMPERATURE MODULE,
COMPASS/MINI-TRIP COMPUTER or
ELECTRONIC VEHICLE INFORMATION CENTER
The
Compass/Temperature
Module
(CT),
Compass/Mini-Trip Computer (CMTC) or Elec-
tronic Vehicle Information Center (EVIC) is located
in the overhead console. The CT provides the vehi-
cle operator with only outdoor temperature and the
compass heading. The CMTC or EVIC supplements
the standard vehicle instrumentation. The CMTC
and EVIC use a vacuum fluorescent (VF) display to
supply the vehicle operator with a compass head-
ing, outdoor temperature, average fuel economy,
distance to empty, trip odometer, elapsed ignition
on time, distance to service, warning messages, and
service messages.
The difference between a CMTC and an EVIC is
that only the EVIC provides additional memory,
feature programming, and warning messages. The
EVIC is capable of displaying warning messages
and memory system messages when the vehicle is
equipped with memory systems. The EVIC also
provides the interface to enable and disable vehicle
programmable
features
when
the
vehicle
is
equipped with certain features.
If equipped, the EVIC is also available with an
integrated Universal Garage Door Opener (UGDO)
known as HomeLink
t. The EVIC may also be
equipped with up to 4 power door switches: ON/
OFF, Left Sliding Door, Right Sliding Door, and
Liftgate.
29
GENERAL INFORMATION