NOTE: Before replacing the PCM for a failed driver,
control circuit or ground circuit, be sure to check
the related component/circuit integrity for failures
not detected due to a double fault in the circuit.
Most PCM driver/control circuit failures are caused
by internal component failures (i.e. relay and sole-
noids) and shorted circuits (i.e. pull-ups, drivers
and switched circuits). These failures are difficult to
detect when a double fault has occurred and only
one DTC has set.

When a PCM and the SKIM are replaced at the

same time perform the following steps in order:

(1) Program the new PCM.
(2) Program the new SKIM.
(3) Replace all ignition keys and program them to

the new SKIM.

PROGRAMMING THE PCM

The SKIS Secret Key is an ID code that is unique

to each SKIM. This code is programmed and stored
in the SKIM, PCM and transponder chip (ignition
keys). When replacing the PCM it is necessary to
program the secret key into the new PCM using the
scan tool. Perform the following steps to program the
secret key into the PCM.

(1) Turn the ignition switch on (transmission in

park/neutral).

(2) Use the scan tool and select THEFT ALARM,

SKIM then MISCELLANEOUS.

(3) Select PCM REPLACED (GAS ENGINE).
(4) Enter secured access mode by entering the

vehicle four-digit PIN.

(5) Select ENTER to update PCM VIN.

NOTE: If three attempts are made to enter secure
access mode using an incorrect PIN, secured
access mode will be locked out for one hour. To
exit this lockout mode, turn the ignition to the RUN
position for one hour then enter the correct PIN.
(Ensure all accessories are turned off. Also monitor
the battery state and connect a battery charger if
necessary).

(6) Press ENTER to transfer the secret key (the

SKIM will send the secret key to the PCM).

(7) Press Page Back to get to the Select System

menu and select ENGINE, MISCELLANEOUS, and
SRI MEMORY CHECK.

(8) The scan tool will ask, Is odometer reading

between XX and XX? Select the YES or NO button on
the scan tool. If NO is selected, the scan tool will
read, Enter odometer Reading<From I.P. odometer>.
Enter the odometer reading from the Instrument
Panel and press ENTER.

PROGRAMMING THE SKIM

(1) Turn the ignition switch on (transmission in

park/neutral).

(2) Use the scan tool and select THEFT ALARM,

SKIM then MISCELLANEOUS.

(3) Select PCM REPLACED (GAS ENGINE).
(4) Program the vehicle four-digit PIN into SKIM.
(5) Select COUNTRY CODE and enter the correct

country.

NOTE: Be sure to enter the correct country code. If
the incorrect country code is programmed into
SKIM, the SKIM must be replaced.

(6) Select YES to update VIN (the SKIM will learn

the VIN from the PCM).

(7) Press ENTER to transfer the secret key (the

PCM will send the secret key to the SKIM).

(8) Program ignition keys to SKIM.

NOTE: If the PCM and the SKIM are replaced at the
same time, all vehicle keys will need to be replaced
and programmed to the new SKIM.

PROGRAMMING IGNITION KEYS TO THE SKIM

(1) Turn the ignition switch on (transmission in

park/neutral).

(2) Use the scan tool and select THEFT ALARM,

SKIM then MISCELLANEOUS.

(3) Select PROGRAM IGNITION KEY’S.
(4) Enter secured access mode by entering the

vehicle four-digit PIN.

NOTE: A maximum of eight keys can be learned to
each SKIM. Once a key is learned to a SKIM it (the
key) cannot be transferred to another vehicle.

If ignition key programming is unsuccessful, the

scan tool will display one of the following messages:

Programming Not Attempted - The scan tool

attempts to read the programmed key status and
there are no keys programmed into SKIM memory.

Programming Key Failed (Possible Used Key From

Wrong Vehicle) - SKIM is unable to program key due
to one of the following:

• faulty ignition key transponder

• ignition key is programmed to another vehicle.
8 Keys Already Learned, Programming Not Done -

SKIM transponder ID memory is full.

8E - 2

ELECTRONIC CONTROL MODULES

(5) Obtain ignition keys to be programmed from

customer (8 keys maximum).

(6) Using the scan tool, erase all ignition keys by

selecting MISCELLANEOUS and ERASE ALL CUR-
RENT IGN. KEYS.

(7) Program all ignition keys.
Learned Key In Ignition - Ignition key transponder

ID is currently programmed in SKIM memory.

BODY CONTROL MODULE

DESCRIPTION

The Body Control Module (BCM) is located in the

passenger compartment, attached to the bulkhead
underneath the left side of the instrument panel.

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 vehicle
through both hard wired outputs and the transmis-
sion of electronic message outputs to other electronic
modules in the vehicle over the PCI data bus.

OPERATION

The Body Control Module (BCM) supplies vehicle

occupants with visual and audible information and
controls various vehicle functions. To provide and
receive information, the BCM is interfaced to the
vehicle’s serial bus communications network, referred
to as the Programmable Communications Interface
(PCI) bus.

This network consists of the;
• Powertrain Control Module (PCM)

• Transmission Control Module (TCM)

• Mechanical Instrument Cluster (MIC)

• Occupant Restraint Controller (ORC)

• Compass/Mini-Trip Computer (CMTC)

• Electronic Vehicle Information Center (EVIC)

• Controller Antilock Brake (CAB)

• HVAC Control Module

• Sliding Door Control Modules (driver and pas-

senger side doors)

• Power Liftgate Module (PLG)

• Audio system equipped with RAZ, RBU, RBK,

and RBB radios.

• Sentry Key Remote Entry Module (SKREEM).

• Side Impact Airbag Control Module (SIACM)

• Memory Seat Module (MSM)

• Sentry Key Immobilizer Module (SKIM)
The BCM is operational when battery power is

supplied to the module.

The BCM provides the following features:
• Power Door Locks

• Automatic Door Locks

• Battery Protection - The BCM will automatically

turn off all exterior lamps after 3 minutes, and all
interior lamps after 15 minutes after the ignition is
turned off, if they are not turned off by the driver.

• Chime Control

• Compass/Mini-Trip support.

• Interior Lighting (Courtesy/Reading Lamps)

• BCM Diagnostic Reporting

• Electronic Liftgate Release (with Power Door

Locks)

• Exterior Lighting

• Headlamp Time Delay (with/without Automatic

Headlamps)

• Illuminated Entry

• Fade to Off Interior Lamps - This feature dims

the interior lighting (courtesy lamps) gradually if the
BCM does not receive any new inputs that would
cause the interior lamps to remain on.

• Pulse Width Modulated Instrument Panel Dim-

ming

• Door Lock Inhibit - This feature disables the

door lock functions if the key is in the ignition and
either front door is ajar. Pressing the Remote Keyless
Entry (RKE) lock/unlock button under these condi-
tions result in normal lock/unlock activation.

The BCM has the ability to LEARN additional fea-

tures in the vehicle, provided the appropriate switch
input and PCI data bus messages are received. Refer
to the LEARNED FEATURES table.

ELECTRONIC CONTROL MODULES

8E - 3

ELECTRONIC CONTROL MODULES (Continued)

LEARNED FEATURES

FEATURE

LEARNING KEY

REAR WIPER CONTROL ON HVAC CONTROL ON
INSTRUMENT PANEL

PCI BUS MESSAGE RECEIVED FROM HVAC
CONTROL

AUTOMATIC HEADLAMPS

PCI MESSAGE FROM OVERHEAD OR HEADLAMP
SWITCH POSITION (AUTO)

REMOTE KEYLESS ENTRY

SKREEM MESSAGE RECEIVED FROM MODULE

FRONT FOG LAMPS

HEADLAMP SWITCH POSITION (PARK W/FRONT
FOG LAMPS)

POWER SLIDING DOOR

PCI IFR RECEIVED FROM MODULE

THE BCM HAS FOUR SWITCH INPUTS FOR THE POWER SLIDING DOOR FEATURE; LOCATED IN THE
OVERHEAD CONSOLE ARE THE LEFT AND RIGHT SIDE SLIDING DOOR SWITCHES TO ACTIVATE EITHER
OR BOTH SLIDING DOORS UNDER THE PROPER CONDITIONS. ALSO ARE B-PILLAR SWITCHES LOCATED
ON THE LEFT AND RIGHT B-PILLAR POSTS.

POWER LIFTGATE

PCI IFR RECEIVED FROM MODULE

THE BCM HAS ONE LIFTGATE INPUT LOCATED IN THE OVERHEAD CONSOLE.

POWER LOCKOUT SWITCH INPUT

THE BCM HAS ONE LOCKOUT SWITCH INPUT THAT WHEN ENABLED WILL DISABLE THE B-PILLAR
SLIDING DOOR SWITCHES FROM ACTIVATING EITHER SLIDING DOOR WHEN DEPRESSED.

PCI AUDIO SYSTEM

PCI MESSAGE RECEIVED FROM MODULE

REMOTE RADIO CONTROLS

REMOTE RADIO SWITCHES PRESENT

VEHICLE THEFT SECURITY

SKREEM MESSAGE RECEIVED, VALID KEY
RECEIVED, & DIAGNOSTIC PID RECEIVED.

MEMORY SEAT AND MIRRORS

MEMORY SEAT SWITCH PRESENT AND OR PCI
MESSAGE RECEIVED FROM MEMORY MODULE

ABS W/TRACTION CONTROL

PCI MESSAGE RECEIVED FROM CAB

SENTRY KEY IMMOBILIZER SYSTEM

PCI MESSAGE RECEIVED FROM SKIM OR VTSS
PRESENT

ADJUSTABLE PEDAL MODULE

PCI MESSAGE RECEIVED FROM ADJUSTABLE
PEDAL MODULE (APM)

When replacing a BCM there are three modules

available:

• Base

• Midline

• RG - Export
The Midline controller is used on vehicles that

have Power Door Locks. If a vehicle is equipped with
the Vehicle Theft Security System, the Midline con-
troller becomes a Premium when the theft feature is
enabled.

CAUTION: Do not swap Body Control Modules
between vehicles or body controller’s off the shelf.

The BCM has internal diagnostic capability that

assists in diagnosing the system error. When an
OPEN or a SHORT circuit exists, the diagnostic tool
can be used to read the BCM faults. The faults are

very descriptive in identifying the appropriate fea-
ture that has faulted.

The only two faults that the BCM logs that con-

clude the replacement of a BCM are faults;

• # 01 - Internal BCM failure (replace BCM)

• # 1F - J1850 Internal Hardware Failure (replace

BCM)

Otherwise the appropriate diagnostic procedures

for each of the features should be taken when the
BCM logs a fault.

REMOVAL

(1) Disconnect and isolate the battery negative

cable.

(2) Remove the lower instrument panel silencer.
(3) Remove the knee blocker and reinforcement

(Refer to 23 - BODY/INSTRUMENT PANEL/KNEE
BLOCKER REINFORCEMENT - REMOVAL).

8E - 4

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BODY CONTROL MODULE (Continued)

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