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AIRBAG SYSTEM
The airbag system is designed to provide increased driver and passenger protection if the vehicle is involved in a front end collision. The system is most effective when used in conjunction with the seat belt system.

Both driver and passenger side airbag assemblies are now hybrid type which utilize a canister of compressed, inert gas to inflate the bag, instead of sodium azide.

Currently, Chrysler Corporation uses two types of airbag control modules. The ASDM system is a mechanically-triggered system utilizing two front impact sensors and a sensor inside the module. The AECM (AB, JX, JA and NS bodies only) is an electronically-triggered system that uses only its own internal electronic sensor to trigger the airbags. This will address the AECM type of module. The term "Airbag Control Module" (or ACM) will be used to refer to the module.

Functional Operation
Whenever the ignition key is turned to the "RUN" or "START" position, the Airbag Control Module (ACM) performs a lamp check by turning the AIRBAG warning lamp ON. The lamp stays lit for 6 - 8 seconds, then goes OFF. If the lamp remains OFF, it means that the ACM has checked the system and found it to be free of discernible malfunctions. The airbag system is monitored by the ACM.

The ACM monitors critical input and output circuits within the airbag system, making sure they are operating correctly. Some circuits are tested continuously; others are checked only under certain circumstances. The ACM provides diagnostic information about the airbag system to the technician through the DRB III via the CCD bus.

The deceleration or g-force resulting from the impact of a front-end collision causes the electronic sensor inside of the ACM to be triggered. This causes the inflators to be actuated, thus deploying the airbags. The total time between determining to deploy and full inflation of the airbag is approximately 4O ms.

A new enhanced accident response feature has been added. This feature, upon deployment of the airbag, turns ON the interior lights and unlocks the power door locks (if equipped).

The AIRBAG warning lamp is the only point at which "symptoms" of a system malfunction can be observed by the customer.

Use the test procedures in this book to find the cause of any customer complaint regarding the AIRBAG warning lamp, such as:
- warning lamp does not come ON at all
- warning lamp stays ON

BODY CONTROL MODULE
The Body Control Module (BCM) supplies vehicle occupants with visual and audible information and controls various vehicle functions. To provide and receive information, the module is interfaced to the vehicle's serial bus communications network (the Chrysler Collision Detection bus, or CCD bus). This network consists of the powertrain control module (PCM), the transmission control module (TCM), the electro/mechanical instrument cluster (MIC), the airbag control module (ACM), the compass/mini-trip module, the controller antilock brake (CAB) module and the HVAC control module. The BCM is operational when battery power is supplied to the module. Ignition switch power is needed for ignition switch functions.

The Body Control Module provides the following features:
- automatic door locks
- battery protection
- CCD radio
- chimes
- compass/mini-trip support
- courtesy lamps
- BCM diagnostic support
- door lock inhibit
- headlamp time delay
- ignition key lamp
- illuminated entry
- instrument panel dimming
- mechanical instrument cluster support
- power door locks (with/without remote keyless entry)
- sliding door memory lock
- vehicle theft security system (VTSS)
- windshield wipers /washers (front and rear)

When replacing a Body Control Module there are 2 modules available, a Base and a Midline. 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 controller becomes a premium when the theft feature is enabled. To enable the VTSS when a module is replaced, open the hood and insert the key in the liftgate and turn it to the unlock position. When this is completed cycle the ignition switch from OFF to ON and observe the VTSS indicator for bulb check. This will verify that vehicle theft is enabled. If the vehicle is equipped with VTSS it must be enabled when the BCM is replaced or the engine will not start.

Battery Protection: "Park & Headlamps"
This feature provides a battery protection scheme to avoid wearing down the battery if the customer leaves the parklamps or headlamps ON for extended periods of time with the ignition OFF. If the parklamp or headlamp switch remains in the active position for more than 3 minutes, while the ignition is OFF, the parklamps and or headlamps will be turned OFF and the input causing the lamps to be ON will be ignored. Once the 3 minute timeout has elapsed the BCM will enter sleep mode. Any change in any inputs monitored by the BCM that brings the BCM out of sleep mode, will reset the 3 minute timer (door lock/unlock), door ajar, ignition, RKE actuation, etc.).

Leaving the ignition switch in an active position (steering column unlocked, ignition ON or accessory power on) will inhibit the battery protection routine from turning off the exterior lamps as described above.

Battery Protection: "Reading & Glove Box Lamps"
This feature provides a battery protection scheme to avoid wearing down the battery due to leaving a reading lamp on, glove box open or visor vanity mirrors ON. The BCM provides a ground circuit for these interior lamps. This ground path is connected whenever the ignition is ON but is always disconnected 15 minutes after the BCM enters sleep mode. Once the 15 minutes timeout has expired, any monitored input that brings the BCM out of sleep mode (ignition/unlock switch, door ajar switches, dome lamp switch, RKE/Central Unlock actuation etc.) will reset the 15 minute timer and return the reading, glove box lamps and vanity mirrors to normal operation (normal operation defined as: "ON" is reading lamp and visor vanity mirrors ON, or glove box open; "OFF" if reading lamp and visor vanity mirrors OFF, and glove box closed).

Leaving the keys in the ignition switch, while the ignition is OFF, will not inhibit the battery protection from turning OFF these interior lamps as described above. Leaving the ignition switch in an active position (steering column unlocked, ignition ON or accessory power ON) will inhibit the battery protection routine from turning off these interior lamps as described above.

Shipping Mode
By definition, shipping mode is when the IOD fuse is removed from the vehicle. The BCM receives its primary power feed from the battery via the IOD fuse. The BCM also receives a back-up power feed from the ignition Run/Start signal. During shipping mode the illuminated entry, courtesy lamps, key-in lamps, reading lamps and glove box lamps will not operate until the IOD is reconnected or the ignition switch is turned to the run/start position.

Exterior Headlamp Control
The headlamps and parklamps are illuminated via external relays which are controlled by the Body Control Module (BCM). When the parklamp switch is closed to ground the BCM grounds the parklamp relay coil which provides the power to the parklamps. This same parklamp power feed is also wired back into the BCM to provide the power feed for the PWM circuit. When the headlamp switch is closed to ground the BCM grounds both the low beam and high beam headlamp relays. The position of the hi-beam select switch will determine the mode of operation. Note: On Chrysler vehicle line when the high beams are selected both high beams and low beams will be illuminated. Dodge and Plymouth vehicle lines support only one mode of operation at a time.

Auto Headlamps
On vehicles equipped with the auto headlamp feature, the BCM will control the exterior lamp operation by monitoring the mode selection switch located in the headlamp control panel. When auto headlamp mode is selected the BCM will then monitor for a ON/OFF signal from the ElectroChromatic Rear View Mirror. The mirror will determine the appropriate ambient light levels for turning ON/OFF the exterior lamps. If in auto headlamp mode, exterior lamps are ON (due to darkness), and the ignition switch is cycled OFF, the BCM will enter headlamp delay mode (see Headlamp Delay Feature description).

Headlamp Time Delay
The headlamp delay feature keeps the headlamps ON for 60 seconds giving the driver and passengers security lighting when exiting the vehicle. This feature is only available on vehicles equipped with RKE. The Headlamp Delay feature is activated by sequentially turning off the ignition, then both the headlamps and parklamps. The headlamps and parklamps must be turned OFF within 45 seconds of ignition transition to OFF to activate the headlamp delay. Once the headlamp delay has been activated the headlamps will remain ON for 60 seconds or until a parklamp, headlamp, auto headlamp or the ignition switch changes states.

Chime System
The chime system provides the driver with two types of chimes: warning and announcement. Warning chimes are provided for dome lamps ON, engine temperature lamp, exterior lamps ON, key-in ignition, low oil pressure, and turn signal ON (greater than one mile above 15 mph). The warning chime will sound continuously until the condition is removed or the battery protection stops the chime (3 or 4 minutes). The driver seat belt unfastened chime will sound for approximately six seconds or until the seat belt is fastened. The announcement chime will sound one time whenever the generator lamp, low fuel, low washer fluid, door ajar, airbag, or liftgate ajar lamps are first illuminated. The door and liftgate ajar lamp announcement chime is only given if the vehicle speed is above 2 mph. Diagnostics for the announcement chime are covered under the instrument cluster warning lamp diagnostics.

COMPASS/MINI-TRIP COMPUTER
The compass/mini-trip computer is located in the overhead console. It displays to the driver the direction the vehicle is traveling and the current outside temperature, as well as the following traveler navigational information: Average Fuel Economy (AVG ECO), Distance To Empty (DTE), Instantaneous Fuel Economy (ECO), Elapsed Time (ET), and Trip Odometer (ODO). The information needed for the traveler functions is received over the CCD bus from the Body Control Module.

If the compass/mini-trip computer has been replaced, it may be necessary to reset the calibration.

Setting The Compass
The Compass/Mini-Trip Module is self-calibrated and requires no adjustment. The word CAL will be displayed to indicate that the compass is in the fast calibrating mode. CAL will turn off after the vehicle has gone in three complete circles without stopping, in an area free of magnetic disturbance.

If the module displays the temperature while the compass is blank or shows a false reading, the vehicle must be demagnetized.

If the compass still goes blank after the vehicle is demagnetized, the Compass/Mini-Trip Module must be replaced.

Setting The Variance:

Setting The Variance
Variance is the difference between magnetic north and geographic north. To determine the variance for the area you are in, refer to the following zone map provided. The number shown for your area is the variance number for your area.

1. Set the Compass/Mini-Trip Console (CMTC) to compass/temperature mode.
2. Press and hold down the RESET button for 5 seconds.

NOTE: If the button is held for 10 seconds instead of 5 seconds, the CMTC will set the variance to 8 and enter the fast calibration mode.

3. The VAR light will come ON and the last variance setting will be displayed.
4. Press the STEP button to set the zone number.
5. Press the US/M button and resume normal operation.

NOTE: DO NOT ATTACH ANY MAGNETIC DEVICE SUCH AS A MAGNETIC CB ANTENNA TO THE VEHICLE. THIS CAN CAUSE THE COMPASS TO GIVE FALSE READINGS.

MECHANICAL INSTRUMENT CLUSTER(MIC)
The body control module sends the angular position of the gauges, the status of all CCD indicator lamps, the status and dimming of the mechanical instrument cluster (MIC) over the CCD bus when the ignition is in the "OFF" (unlock), "RUN", or "START" positions. The PRNDL (VF, if equipped) and odometer/trip displays work when the ignition is in the "OFF" (unlock), "RUN", or "START" positions; all other MIC features work Only when ignition is in the "RUN" position. On transition of the ignition from the "OFF" to the "RUN" position, a bulb check is performed. This consists of activating all CCD controlled indicator lamps and all VF display segments for approximately 2 - 4 seconds. The PRNDL bulb check is aborted if the gear selector is moved from the PARK position, or if the engine exceeds 450 rpm.