2002 JEEP GRAND CHEROKEE instrument

INSTALLATION
(1) Install the module on the mounting pins in the
vehicle.
(2) Reconnect the electrical connector.
(3) Install the two mounting clips for the module
(Fig. 1).
(4) Install the adjustable pedal motor. (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/PEDAL -
INSTALLATION).
(5) Install the steering column opening cover
(Refer to 23 - BODY/INSTRUMENT PANEL/STEER-
ING COLUMN OPENING COVER - INSTALLA-
TION).
(6) Install the cluster bezel (Refer to 23 - BODY/
INSTRUMENT PANEL/CLUSTER BEZEL -
INSTALLATION).
(7) Reconnect the negative battery cable.
BODY CONTROL MODULE
DESCRIPTION
A Body Control Module (BCM) is concealed below
the driver side end of the instrument panel (Fig. 2).
The BCM utilizes integrated circuitry and informa-
tion carried on the Programmable Communications
Interface (PCI) data bus network along with many
hard wired inputs to monitor many sensor and
switch inputs throughout the vehicle. In response to
those inputs, the internal circuitry and programming
of the BCM allow it to control and integrate many
electronic functions and features of the vehiclethrough both hard wired outputs and the transmis-
sion of electronic message outputs to other electronic
modules in the vehicle over the PCI data bus. The
electronic functions and features that the BCM sup-
ports or controls include the following:
The BCM for this model is serviced only as a com-
plete unit. Many of the electronic features in the
vehicle controlled or supported by the BCM are pro-
grammable using either the Electronic Vehicle Infor-
mation Center (EVIC) user interface, or the DRBIIIt
scan tool. In addition, the BCM software is Flash
compatible, which means it can be reprogrammed
using Flash reprogramming procedures. A BCM can
only be repaired by or replaced through an autho-
rized electronic warranty repair station. Refer to the
latest version of the Warranty Policies and Proce-
dures manual for a current listing of authorized elec-
tronic repair stations.OPERATION
The Body Control Module (BCM) is designed to
control and integrate many of the electronic features
and functions of the vehicle. The microprocessor-
based BCM hardware and software monitors many
hard wired switch and sensor inputs as well as those
resources it shares with other electronic modules in
the vehicle through its communication over the PCI
data bus network. The internal programming of the
BCM microprocessor allows the BCM to determine
the tasks it needs to perform and their priorities. The
Fig. 1 ADJUSTABLE PEDALS MODULE
1 - ELECTRICAL CONNECTOR
2 - MODULE MOUNTING BRACKET
3 - BRAKE BOOSTER
4 - ADJUSTABLE PEDALS MOUNTING BRACKET
5 - ADJUSTABLE PEDALS CONTROL MODULE
6 - HOLD DOWN CLIPS
Fig. 2 Body Control Module
1 - JUNCTION BLOCK
2 - SCREWS (4)
3 - BODY CONTROL MODULE
4 - FUSE COVER LOCATOR CHANNELS
5 - FUSE COVER MOUNTING SLOTS
6 - INSTRUMENT PANEL WIRE HARNESS CONNECTORS
WJELECTRONIC CONTROL MODULES 8E - 3
ADJUSTABLE PEDALS MODULE (Continued)

inputs to or receive outputs from the BCM must also
be checked. The most reliable, efficient, and accurate
means to diagnose the BCM, the PCI data bus net-
work, and the electronic modules that provide inputs
to or receive outputs from the BCM requires the use
of a DRBIIItscan tool and the appropriate diagnostic
information. The DRBIIItscan tool can provide con-
firmation that the PCI data bus network is func-
tional, that all of the modules are sending and
receiving the proper messages over the PCI data bus,
and that the BCM is receiving the proper hard wired
inputs and responding with the proper hard wired
outputs needed to perform its many functions.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the instrument panel fuse cover.(Refer
to 8 - ELECTRICAL/POWER DISTRIBUTION/FUSE
COVER - REMOVAL).
(3) Access and disconnect the instrument panel
wire harness connectors from the BCM (Fig. 3).
(4) Remove the mounting screws (Torx T-20) that
secure the BCM to the JB.(5) Pull the BCM straight out towards the dash
panel far enough to disconnect the integral BCM to
JB connector.
(6) Remove the BCM.INSTALLATION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Position the Body Control Module (BCM) to its
mounting location (Fig. 3).
(2) Align the terminal pins of the BCM connector
with the connector on the JB.
(3) Engage the BCM integral connector into the
JB.
(4) Install the four screws. Tighten the screws to
2.2 N´m (20 in. lbs.).
Fig. 3 Body Control Module Remove/Install
1 - JUNCTION BLOCK
2 - SCREWS (4)
3 - BODY CONTROL MODULE
4 - FUSE COVER LOCATOR CHANNELS
5 - FUSE COVER MOUNTING SLOTS
6 - INSTRUMENT PANEL WIRE HARNESS CONNECTORS
WJELECTRONIC CONTROL MODULES 8E - 5
BODY CONTROL MODULE (Continued)

(5) Connect the two instrument panel wire harness
connectors to the BCM.
(6) Reinstall the instrument panel fuse cover to
the bottom of the BCM and JB unit. (Refer to 8 -
ELECTRICAL/POWER DISTRIBUTION/FUSE
COVER - INSTALLATION).
(7) Connect the battery negative cable.
COMMUNICATION
DESCRIPTION
The Programmable Communication Interface (PCI)
data bus system is a single wire multiplex system
used for vehicle communications. Multiplexing is a
system that enables the transmission of several mes-
sages over a single channel or circuit.
Many of the control modules in a vehicle require
information from the same sensing device. Multiplex-
ing reduces wire harness complexity, sensor current
loads and controller hardware because each sensing
device is connected to only one controller, which
reads and distributes the sensor information to the
other controllers over the data bus. Also, because
each controller on the data bus can access the con-
troller sensor inputs to every other controller on the
data bus, more function and feature capabilities are
possible.
A multiplex system allows the information flowing
between controllers to be monitored using a diagnos-
tic scan tool. This system allows a control module to
broadcast message data out onto the bus where all
other control modules can read the messages that are
being sent. When a module reads a message on the
data bus that it requires, it relays that message to
its microprocessor. Each module ignores the mes-
sages on the data bus that it dosen't recognize.
OPERATION
Data exchange between modules is achieved by
serial transmission of encoded data over a single wire
broadcast network. The PCI data bus messages are
carried over the bus in the form of Variable Pulse
Width Modulated (VPWM) signals. The PCI data bus
speed is an average 10.4 Kilo-bits per second (Kbps).
The voltage network used to transmit messages
requires biasing and termination. Each module on
the PCI data bus system provides its own biasing
and termination. Each module (also referred to as a
node) terminates the bus through a terminating
resistor and a terminating capacitor. The Powertrain
Control Module (PCM) is the only dominant node for
the PCI data bus system.
The PCI bus uses low and high voltage levels to
generate signals. The voltage on the buss varies
between zero and seven and one-half volts. The lowand high voltage levels are generated by means of
variable-pulse width modulation to form signals of
varying length.
When a module is transmitting on the bus, it is
reading the bus at the same time to ensure message
integrity.
Each module is capable of transmitting and receiv-
ing data simultaneously.
The PCI data bus can be monitored using the
DRBIIItscan tool. It is possible for the bus to pass
all DRBIIIttests and still be faulty if the voltage
parameters are all within the specified range and
false messages are being sent.
CONTROLLER ANTILOCK
BRAKE
DESCRIPTION
The Controler Antilock Brake (CAB) is mounted to
the Hydraulic Control Unit (HCU) and operates the
ABS system (Fig. 4).
OPERATION
The CAB voltage is supplied by the ignition switch
in the RUN position. The CAB contains dual micro-
processors. A logic block in each microprocessor
receives identical sensor signals. These signals are
processed and compared simultaneously. The CAB
contains a self check program that illuminates the
ABS warning light when a system fault is detected.
Faults are stored in a diagnostic program memory
and are accessible with the DRBIIItscan tool. ABS
faults remain in memory until cleared, or until after
the vehicle is started approximately 50 times. Stored
Fig. 4 Controller Antilock Brakes
1 - HCU
2 - MOTOR
3 - CAB
8E - 6 ELECTRONIC CONTROL MODULESWJ
BODY CONTROL MODULE (Continued)

faults arenoterased if the battery is disconnected.
(Fig. 4)
REMOVAL
(1) Remove negative battery cable from the bat-
tery.
(2) Remove air cleaner housing,(Refer to 9 -
ENGINE/AIR INTAKE SYSTEM/AIR CLEANER
HOUSING - REMOVAL) OR (Refer to 9 - ENGINE/
AIR INTAKE SYSTEM/AIR CLEANER HOUSING -
REMOVAL).
(3) Release CAB harness connector and remove
connector (Fig. 5).
(4) Remove pump motor connector.
(5) Remove CAB mounting bolts (Fig. 6) and
remove the CAB from the HCU.
INSTALLATION
(1) Install the CAB onto the HCU and tighten
mounting bolts to 1.8 N´m (16 in. lbs.).
(2) Install pump motor connector.
(3) Install CAB harness connector and push down
connector release.
(4) Install air cleaner housing,(Refer to 9 -
ENGINE/AIR INTAKE SYSTEM/AIR CLEANER
HOUSING - INSTALLATION) OR (Refer to 9 -
ENGINE/AIR INTAKE SYSTEM/AIR CLEANER
HOUSING - INSTALLATION).
(5) Install negative battery cable to the battery.
DATA LINK CONNECTOR
DESCRIPTION - DATA LINK CONNECTOR
The data link connector (DLC) is located at the
lower edge of the instrument panel near the steering
column.
OPERATION - DATA LINK CONNECTOR
The 16±way DLC links the DRBIIItscan tool or
the Mopar Diagnostic System (MDS) with the Power-
train Control Module (PCM).
DOOR MODULE
DESCRIPTION
A door module is concealed behind the trim panel
of each front door (Fig. 7).The module on the driver
side is referred to as the Driver Door Module (DDM),
while the module on the passenger side is the Pas-
senger Door Module (PDM). Each door module
houses both the front power lock and power window
switches. In addition to the power window and power
lock switches for its own door, the DDM also houses
individual switches for each passenger door power
window, a power window lockout switch, the power
mirror switch, and the power foldaway mirror switch
for export vehicles.
The DDM and PDM each utilize integrated cir-
cuitry and information carried on the Programmable
Communications Interface (PCI) data bus network
along with many hard wired inputs to monitor many
sensor and switch inputs throughout the vehicle. The
PDM also receives inputs through an integral Radio
Fig. 5 CAB Connector Release
1 - CONNECTOR RELEASE
2 - CAB
Fig. 6 CAB Mounting Bolts
1 - MOUNTING BOLTS
WJELECTRONIC CONTROL MODULES 8E - 7
CONTROLLER ANTILOCK BRAKE (Continued)

DIAGNOSIS AND TESTING - DOOR MODULE
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
The hard wired inputs to and outputs from the
Driver Door Module (DDM) or the Passenger Door
Module (PDM) may be diagnosed and tested using
conventional diagnostic tools and procedures. It is
suggested that the proper operation of the inopera-
tive power window motor, power door lock motor,
power liftgate lock motor, power mirror motors, or
heated mirror grid be confirmed using jumper wires
to bypass the door module. If the inoperative compo-
nent operates when the door module is bypassed,
check the circuits between the component and the
door module, as well as the fused B(+) and ground
circuits of the door module for shorts or opens.
These conventional diagnostic methods may not
prove conclusive in the diagnosis of the DDM or the
PDM. In order to obtain conclusive testing of these
modules, the Programmable Communications Inter-
face (PCI) data bus network and all of the modules
that provide inputs to or receive outputs from the
door modules must also be checked. The most reli-
able, efficient, and accurate means to diagnose the
DDM, the PDM, the PCI data bus network, and the
modules that provide inputs to or receive outputs
from the door modules requires the use of a DRBIIIt
scan tool and the appropriate diagnostic information.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the trim panel from the front door.
(Refer to 23 - BODY/DOOR - FRONT/TRIM PANEL -
REMOVAL).
(3) Remove the door module from the back of the
front door trim panel (Fig. 8).
(4) Remove the door module from the front door
trim panel.
INSTALLATION
(1) Position the door module onto the front door
trim panel.
(2) Install the door module to the back of the front
door trim panel (Fig. 8). Tighten the screws to 2.2
N´m (20 in. lbs.).
(3) Reinstall the trim panel onto the front door.
(Refer to 23 - BODY/DOOR - FRONT/TRIM PANEL -
INSTALLATION).
(4) Reconnect the battery negative cable.
MEMORY HEATED SEAT/
MIRROR MODULE
DESCRIPTION
There are two different modules that can be used
in the optional heated seat system. The Heated Seat
Module (HSM) is used on vehicles that are not
equipped with the optional Memory System. The
Memory Heated Seat Module (MHSM) is used on
vehicles that are equipped with the optional Memory
System and the optional heated seat system.Refer to
Memory Systemin Power Seat Systems for more
information on the memory system option.
The module is mounted on a bracket that is located
between the power seat track and the seat cushion
frame (Fig. 9). The HSM or MHSM is used to control
the heated seat system functions for both front seats.
The HSM or MHSM contains a central processing
unit that communicates with other modules on the
Fig. 8 Door Module Remove/Install
1 - FRONT DOOR TRIM PANEL
2 - SCREW (5)
3 - DOOR MODULE
8E - 10 ELECTRONIC CONTROL MODULESWJ
DOOR MODULE (Continued)

sponder through a tuned antenna ring integral to the
SKIM housing. If this antenna ring is not mounted
properly around the ignition lock cylinder housing,
communication problems between the SKIM and the
transponder may arise. These communication prob-
lems will result in Sentry Key transponder-related
faults. The SKIM also communicates over the Pro-
grammable Communications Interface (PCI) data bus
with the Powertrain Control Module (PCM), the Elec-
troMechanical Instrument Cluster (EMIC), the Body
Control Module (BCM), and/or the DRBIIItscan tool.
The SKIM retains in memory the ID numbers of
any Sentry Key transponder that is programmed into
it. A maximum of eight transponders can be pro-
grammed into the SKIM. For added system security,
each SKIM is programmed with a unique Secret Key
code. This code is stored in memory, sent over the
PCI data bus to the PCM, and is encoded to the tran-
sponder of every Sentry Key that is programmed into
the SKIM. Another security code, called a PIN, is
used to gain access to the SKIM Secured Access
Mode. The Secured Access Mode is required during
service to perform the SKIS initialization and Sentry
Key transponder programming procedures. The
SKIM also stores the Vehicle Identification Number
(VIN) in its memory, which it learns through a PCI
data bus message from the PCM during SKIS initial-
ization.
In the event that a SKIM replacement is required,
the Secret Key code can be transferred to the new
SKIM from the PCM using the DRBIIItscan tool
and the SKIS replacement procedure. Proper comple-
tion of the SKIS initialization will allow the existing
Sentry Keys to be programmed into the new SKIM so
that new keys will not be required. In the event that
the original Secret Key code cannot be recovered,
SKIM replacement will also require new Sentry
Keys. The DRBIIItscan tool will alert the technician
during the SKIS replacement procedure if new Sen-
try Keys are required.
When the ignition switch is turned to the On posi-
tion, the SKIM transmits an RF signal to the tran-
sponder in the ignition key. The SKIM then waits for
an RF signal response from the transponder. If the
response received identifies the key as valid, the
SKIM sends a valid key message to the PCM over
the PCI data bus. If the response received identifies
the key as invalid, or if no response is received from
the key transponder, the SKIM sends an invalid key
message to the PCM. The PCM will enable or disable
engine operation based upon the status of the SKIM
messages. It is important to note that the default
condition in the PCM is an invalid key; therefore, if
no message is received from the SKIM by the PCM,
the engine will be disabled and the vehicle immobi-
lized after two seconds of running.The SKIM also sends indicator light status mes-
sages to the EMIC over the PCI data bus to tell the
EMIC how to operate the SKIS indicator. This indi-
cator light status message tells the EMIC to turn the
indicator on for about three seconds each time the
ignition switch is turned to the On position as a bulb
test. After completion of the bulb test, the SKIM
sends indicator light status messages to the EMIC to
turn the indicator off, turn the indicator on, or to
flash the indicator on and off. If the SKIS indicator
lamp flashes or stays on solid after the bulb test, it
signifies a SKIS fault. If the SKIM detects a system
malfunction and/or the SKIS has become inoperative,
the SKIS indicator will stay on solid. If the SKIM
detects an invalid key or if a key transponder-related
fault exists, the SKIS indicator will flash. If the vehi-
cle is equipped with the Customer Learn transponder
programming feature, the SKIM will also send mes-
sages to the EMIC to flash the SKIS indicator lamp,
and to the BCM to generate a single audible chime
tone whenever the Customer Learn programming
mode is being utilized. (Refer to 8 - ELECTRICAL/
VEHICLE THEFT SECURITY - STANDARD PRO-
CEDURE - SENTRY KEY TRANSPONDER
PROGRAMMING).
The SKIS performs a self-test each time the igni-
tion switch is turned to the On position, and will
store fault information in the form of Diagnostic
Trouble Codes (DTC's) in SKIM memory if a system
malfunction is detected. The SKIM can be diagnosed,
and any stored DTC's can be retrieved using a
DRBIIItscan tool. Refer to the appropriate diagnos-
tic information.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the steering column opening cover
from the instrument panel. (Refer to 23 - BODY/IN-
STRUMENT PANEL/STEERING COLUMN OPEN-
ING COVER - REMOVAL).
8E - 18 ELECTRONIC CONTROL MODULESWJ
SENTRY KEY IMMOBILIZER MODULE (Continued)

(3) Disconnect the instrument panel wire harness
connector from the SKIM connector.
(4) Remove the screw that secures the SKIM to
the bottom of the steering column housing (Fig. 16).
(5) Disengage the antenna ring of the SKIM from
around the ignition lock cylinder housing.
(6) Remove the SKIM from the steering column.
INSTALLATION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Position the SKIM to the underside of the
steering column (Fig. 16).
(2) Engage the antenna ring of the SKIM around
the ignition lock cylinder housing.
(3) Install and tighten the screw that secures the
SKIM to the bottom of the steering column hous-
ing.Tighten the screw to 3.4 N´m (30 in lbs.).
(4) Reconnect the instrument panel wire harness
connector to the SKIM connector.(5) Reinstall the steering column opening cover
onto the instrument panel. (Refer to 23 - BODY/IN-
STRUMENT PANEL/STEERING COLUMN OPEN-
ING COVER - INSTALLATION).
(6) Reconnect the battery negative cable.
(7) Perform the SKIS Replacement procedure
using the DRBIIIt.
(8) Perform the SKIS Initialization Procedure
using the DRBIIIt.
TRANSMISSION CONTROL
MODULE
DESCRIPTION
The Transmission Control Module (TCM) is located
in the engine compartment on the right (passenger)
side and is mounted to the inner fender (Fig. 17).
OPERATION
The Transmission Control Module (TCM) controls
all electronic operations of the transmission. The
TCM receives information regarding vehicle opera-
tion from both direct and indirect inputs, and selects
the operational mode of the transmission. Direct
inputs are hardwired to, and used specifically by the
TCM. Indirect inputs originate from other compo-
nents/modules, and are shared with the TCM via the
vehicle communication bus.
Some examples ofdirect inputsto the TCM are:
²Battery (B+) voltage
²Ignition ªONº voltage
²Transmission Control Relay (Switched B+)
²Throttle Position Sensor
²Crankshaft Position Sensor
²Transmission Range Sensor
Fig. 16
Fig. 17 Transmission Control Module Location
1 - TRANSMISSION CONTROL MODULE (TCM)
2 - 60±WAY CONNECTOR
WJELECTRONIC CONTROL MODULES 8E - 19
SENTRY KEY IMMOBILIZER MODULE (Continued)

STANDARD PROCEDURE - IGNITION-OFF
DRAW TEST
The term Ignition-Off Draw (IOD) identifies a nor-
mal condition where power is being drained from the
battery with the ignition switch in the Off position. A
normal vehicle electrical system will draw from five
to thirty-five milliamperes (0.005 to 0.035 ampere)
with the ignition switch in the Off position, and all
non-ignition controlled circuits in proper working
order. Up to thirty-five milliamperes are needed to
enable the memory functions for the Powertrain Con-
trol Module (PCM), digital clock, electronically tuned
radio, and other modules which may vary with the
vehicle equipment.
A vehicle that has not been operated for approxi-
mately twenty days, may discharge the battery to an
inadequate level. When a vehicle will not be used for
twenty days or more (stored), remove the IOD fuse
from the Power Distribution Center (PDC). This will
reduce battery discharging.Excessive IOD can be caused by:
²Electrical items left on.
²Faulty or improperly adjusted switches.
²Faulty or shorted electronic modules and compo-
nents.
²An internally shorted generator.
²Intermittent shorts in the wiring.
If the IOD is over thirty-five milliamperes, the
problem must be found and corrected before replac-
ing a battery. In most cases, the battery can be
charged and returned to service after the excessive
IOD condition has been corrected.
(1) Verify that all electrical accessories are off.
Turn off all lamps, remove the ignition key, and close
all doors. If the vehicle is equipped with an illumi-
nated entry system or an electronically tuned radio,
allow the electronic timer function of these systems
to automatically shut off (time out). This may take
up to three minutes. See the Electronic Module Igni-
tion-Off Draw Table for more information.
ELECTRONIC MODULE IGNITION-OFF DRAW (IOD) TABLE
ModuleTime Out?
(If Yes, Interval And Wake-Up Input)IODIOD After Time
Out
Radio No1to3
milliamperesN/A
Audio Power
AmplifierNoup to 1
milliampereN/A
Body Control Module
(BCM)No5.90
milliamperes
(max.)N/A
Powertrain Control
Module (PCM)No 0.95 milliampere N/A
Transmission Control
Module (TCM) 4.7L
w/45RFEYES (20 minutes, ignition on) 130 milliamperes 0.64 milliampere
ElectroMechanical
Instrument Cluster
(EMIC)No 0.44 milliampere N/A
Combination Flasher No 0.08 milliampere N/A
(2) Determine that the underhood lamp is operat-
ing properly, then disconnect the lamp wire harness
connector or remove the lamp bulb.
(3) Disconnect the battery negative cable.
(4) Set an electronic digital multi-meter to its
highest amperage scale. Connect the multi-meter
between the disconnected battery negative cable ter-
minal clamp and the battery negative terminal post.
Make sure that the doors remain closed so that the
illuminated entry system is not activated. The multi-
meter amperage reading may remain high for up tothree minutes, or may not give any reading at all
while set in the highest amperage scale, depending
upon the electrical equipment in the vehicle. The
multi-meter leads must be securely clamped to the
battery negative cable terminal clamp and the bat-
tery negative terminal post. If continuity between the
battery negative terminal post and the negative cable
terminal clamp is lost during any part of the IOD
test, the electronic timer function will be activated
and all of the tests will have to be repeated.
WJBATTERY SYSTEM 8F - 13
BATTERY (Continued)