Stratus Sedan L4-2.4L VIN X (2003)
Body Control Module: Description and Operation
Body Control System
System Description
IDENTIFICATION OF SYSTEM
The vehicle systems that are part of the "body" system are:
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Airbag System
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Audio
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Chimes
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Compass/Mini-Trip
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Door Ajar
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Exterior Lighting
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Heating and A/C
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Interior Lighting
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Mechanical Instrument Cluster
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Power Door Locks/Remote Keyless Entry
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Power Convertible Top
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Vehicle Communications
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Vehicle Theft Security System
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Wiper/Washer
SYSTEM DESCRIPTION
The body system on the 2003 JR consists of a combination of modules that communicate over the PCI bus (Programmable Communication Interface
multiplex system). Through the PCI bus, information about the operation of vehicle components and circuits is relayed quickly to the appropriate
modules. All modules receive all the information transmitted on the bus even though a module may not require all information to perform its function.
It will only respond to messages "addressed" to it through a binary coding process. This method of data transmission significantly reduces the
complexity of the wiring in the vehicle and the size of wiring harnesses. Mi of the information about the functioning of all the systems is organized,
controlled and communicated by the PCI bus, which is described in the Vehicle Communication section of this General Information.
Always begin by reading the diagnostic trouble codes using the DRBIII(R). Next, look for the symptom in the Diagnostic Information and Procedures
section of the Table of Contents located in the front of the book. This will direct you to the specific tests that must be performed.
Important Note:
If the Powertrain Control Module has been changed and the correct VIN and mileage have not been programmed, a DTC will be set in the Airbag
module. In addition, if the vehicle is equipped with a Sentry Key Immobilizer Module (SKIM), Secret Key data must be updated to enable starting.
Refer to the 2003 JR Powertrain Diagnostic for more information. Erase codes in all modules.
Airbag System
AIRBAG SYSTEM
The 2003 Airbag System contains the following components: two types of Occupant Restraint Controller or (ORC), base and premium, Airbag
Warning Indicator, Clockspring, Driver and Passenger Dual Squib Airbags, Seat belt Tensioners, Left and Right Side Impact Sensors, and Curtain
(roof mounted) Airbags. The (ORC) is a new type of Airbag Control Module (ACM) that supports staged airbag deployment. The term Airbag Control
Module or ACM will be used throughout the airbag diagnostic section and in the Diagnostic Readout Box or DRB III(R). The Base ACM can be
identified by the present of a single yellow 23 - way connector. This module supports the Driver and Passenger Seat Belt Tensioners and dual squib
airbags.
The ACM has four major functions: PCI Bus communications, on-board diagnostics, impact sensing, and component deployment. The ACM sends
and/or receives PCI Bus messages with the Instrument Cluster (MIC), Body Control Module (BCM), and Powertrain Control Module (PCM).
Diagnostic trouble codes will be set if the communication with these modules is lost or contains invalid information. If the ACM detects a monitored
system fault, it sends a message to the instrument cluster via PCI bus to turn on the Airbag Warning Indicator. The ACM can set both active and stored
diagnostic trouble codes to aid in the diagnosing system problems. See DIAGNOSTIC TROUBLE CODES.
The ACM has an internal accelerometer that senses the rate of vehicle deceleration, which provides verification of the direction and severity of an
impact. A pre-programmed decision algorithm in the ACM microprocessor determines when the deceleration rate is severe enough to require airbag
system protection. The ACM also uses the crash severity to determine the level of driver and front passenger deployment, staged deployment low
medium or high. Staged deployment is the ability to trigger airbag system squib inflators all at once or individually as needed to provide the
appropriate restraint for the severity of the impact. When the programmed conditions are met, the ACM sends an electrical signal to deploy the
appropriate airbag system components. The ACM stores enough electrical energy to deploy the airbag components for two seconds following a
battery disconnect or failure during an impact.
The Premium ACM can be identified by the present of a two yellow 32 - way connectors and the presents of side curtain airbag. In addition to the base
system components and DTC's the premium ACM supports the Side Impact Sensors, side Curtain Airbags. In addition to the ACM accelerometer the
premium module uses Side Impact Sensors to identify the direction and severity of a side impact and deploy the appropriate side curtain airbag. In
addition to the base ACM DTCs the premium ACM provides DTC's for the additional circuit and component.
