self-resetting circuit breaker to protect them from
overload. However, consecutive or frequent resetting
of the circuit breaker must not be allowed to con-
tinue, or the motor may be damaged.
MEMORY SYSTEM
The Memory Seat Mirror Module (MSMM) receives
battery current through fuse #22 in the Integrated
Power Module (IPM) and the power seat system cir-
cuit breaker, located under the driver side front seat
near the rear edge of the seat cushion pan. The mem-
ory system does not operate with the Ignition-Off
Draw (IOD) fuse removed. The MSMM will drive a
maximum of 2 motors at a time in a given direction.
If conflicting directions are requested, the priority for
response will be approximately as follows:
• Seat Track Rearward or Forward
• Seat Front Down or Up
• Seat Rear Down or Up
• Recliner Rearward or Forward
The inputs from these switches to the MSMM is a
current limited battery source fed by the MSMM.
This protects the MSMM printed circuit board traces
from acting as fuses. All of these switch contact
inputs to the MSMM are normally closed to ground,
except when actuated.
For diagnosis of the MSMM, the Programmable
Communication Interface (PCI) data bus, or the other
electronic modules on the PCI data bus that provide
inputs and outputs for the memory system, the use of
a DRBIII
t or equivalent scan tool and the proper
Diagnostic Procedures information is recommended.
ELECTRONIC VEHICLE INFORMATION CENTER
The Electronic Vehicle Information Center (EVIC)
serves as the user interface for the memory system.
It displays memory system status messages and pro-
vides the user with the means for enabling and dis-
abling the many customer programmable features
available on the vehicle, including those for the mem-
ory system.
(Refer to 8 - ELECTRICAL/OVERHEAD CON-
SOLE/ELECTRONIC VEHICLE INFO CENTER -
DESCRIPTION) for additional information on the
EVIC.
DIAGNOSIS AND TESTING
POWER SEAT SYSTEM
Following are tests that will help to diagnose the
hard wired components and circuits of the power seat
system. However, if the vehicle is also equipped with
the optional memory system, these tests may not
prove conclusive in the diagnosis of the driver side
power seat. In order to obtain conclusive testing of
the driver side power seat with the memory system
option, the Programmable Communications Interface
(PCI) data bus network and all of the electronic mod-
ules that provide inputs to, or receive outputs from
the memory system components must be checked,
(Refer to 8 - ELECTRICAL/POWER SEATS - DIAG-
NOSIS AND TESTING).
WARNING: SOME VEHICLES ARE EQUIPPED WITH
SEATBACK
MOUNTED
AIRBAGS.
BEFORE
ATTEMPTING TO DIAGNOSE OR SERVICE ANY
SEAT OR POWER SEAT SYSTEM COMPONENT
YOU MUST FIRST DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE CABLE. THEN WAIT TWO MIN-
UTES FOR THE SYSTEM CAPACITOR TO DIS-
CHARGE BEFORE FURTHER SYSTEM SERVICE.
THIS IS THE ONLY SURE WAY TO DISABLE THE
AIRBAG SYSTEM. FAILURE TO DO SO COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
(1) If either power seat is completely inoperable,
check the power seat circuit breaker, located under
the trailing edge of the driver side power seat. If the
power seat circuit breaker is OK, continue to the
next step.
(2) Check for proper battery and ground connec-
tions at the power seat switch and/or memory seat
module. Repair any wiring as necessary.
(3) Check the power seat system wire harness con-
nections and pins to ensure proper circuit continuity
and ground paths.
MEMORY SYSTEM
In order to obtain conclusive testing of the memory
system, the Programmable Communications Interface
(PCI) data bus network and all of the electronic mod-
ules that provide inputs to, or receive outputs from
the memory system components must be checked.
The most reliable, efficient, and accurate means to
diagnose the driver side power seat with the memory
system option requires the use of a DRBIII
t or
equivalent scan tool and the proper Diagnostic Proce-
dures information. The DRBIII
t scan tool can pro-
vide confirmation that the PCI data bus is functional,
that all of the electronic modules are sending and
receiving the proper messages on the PCI data bus,
and that the memory system is receiving the proper
hard wired inputs and relaying the proper hard
wired outputs to perform its driver side power seat
functions.
(1) If the driver power seat exhibits an interrupted
or jerky motion, ensure the wire harness is connected
correctly. To verify the concern, obtain a DRB III
t or
equivalent scan tool and energize each axis one at a
time. If any axis stops in approximately 2 seconds
(without hitting the end of travel), the feedback for
RS
POWER SEAT SYSTEM
8N - 33
POWER SEAT SYSTEM (Continued)