Chrysler 2004 Concorde, Service Manual

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Other vehicle equipped electronic modules that
may affect memory system operation are as follows:
•
Body Control Module (BCM) - Refer to Body
Control Module in Electronic Control Modules for
more information.
•
Electronic Vehicle Information Center
(EVIC) - Refer to Electronic Vehicle Information
Center in Overhead Console for more information.
•
Powertrain Control Module (PCM) - Refer to
Powertrain Control Module in Electronic Control
Modules for more information.
Refer to Heated Seat System for more informa-
tion on the heated seat system.
Refer to Wiring for complete circuit diagrams. Fol-
lowing are general descriptions and operations of the
major components in the power/memory seat sys-
tems.
OPERATION
OPERATION - POWER SEAT SYSTEM
The power seat system receives battery current
through a 40 amp fuse in the Power Distribution
Center (PDC) and a 20 amp circuit breaker in the
junction block so that the power seats remain opera-
tional, regardless of the ignition switch position. See
the owner’s manual in the vehicle glove box for more
information on the features, use and operation of the
power seat system.
OPERATION - MEMORY SEAT SYSTEM
The Memory Heated Seat/Mirror Module receives
hard wired inputs from the memory set/position
switch and the potentiometers, mounted on each of
the driver power seat track motors and the driver
side view mirror motor. The programmed software in
the module allows it to know where the seat/mirror
is located in its designed travel by a resistance read-
ing generated from the seat track or mirror mounted
potentiometer. This way, when the memory switch is
depressed the module will power the seat track or
mirror motors until the correct preset location is
achieved. The module will prevent the seat memory
recall function from being initiated, if the transmis-
sion gear selector lever is not in the Park or Neutral
positions, or if the vehicle is moving. These inputs
are monitored over the PCI data bus circuit by the
MHSMM.
See the owner’s manual in the vehicle glove box for
more information on the features, use and operation
of the memory seat system. Refer to Electronic
Vehicle Information Center in Overhead Console
Systems for information on the EVIC.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - POWER SEATS
The following tests will help to diagnose the hard
wired components and circuits of the power seat sys-
tem. 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.
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.
NOTE: Vehicles equipped with the memory/heated
seat option utilize a low voltage cut-off feature. This
feature turns off the 12v power to the power seat
system anytime vehicle voltage is below 11.7v. Be
certain to check the vehicle electrical system for
proper voltage anytime the power seat system
appears inoperational.
The most reliable, efficient, and accurate means to
diagnose the driver side power seat with the memory
system option requires the use of a DRB III
t
scan
tool and the proper Diagnostic Procedures manual.
The DRB III
t
scan tool can provide confirmation that
the PCI data bus is functional, that all of the elec-
tronic 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.
Before any testing of the power seat system is
attempted, the battery should be fully-charged. For
complete circuit diagrams, refer to Power Seat in
the Contents of Wiring Diagrams.
With the dome lamp on, apply the power seat
switch in the direction of the failure. If the dome
lamp dims, the seat may be jamming. Check under
and behind the seat for binding or obstructions. If
LH
POWER SEATS 8N - 13
POWER SEATS (Continued)