replacing BCM on 2000 Chrysler LHS

I am sure by information I received through this site that the BCM is bad. I did a power reset by disconnecting the + battery cable at the positive jump start terminal. That did not change the symptoms. I bought a used BCM but I have read that the BCM must match serial number or a model number?? Any truth to this? Also, I was told if I put in one that does not match my car, it will disable some systems and may never start until a dealer recodes the computers. Please provide some truth to this.

by in Colorado Springs, CO on August 30, 2010
Get Your Car Fixed at a RepairPal Certified Shop.
We certify shops based on expertise, quality work, and verified customer reviews
2 answers 1 comment
ANSWER by , August 31, 2010
This is true that you must replace the BCM with the same Model year and Part number. Also if the VIN programmed in the BCM does not match your vehicles VIN, many of the BCM functions will not work and yes, if your vehicle is equipped with a vehicle theft alarm, it will not start Here are some of the things the BCM controls. 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 Programmable Communication Interface or PCI bus). This network consists of the powertrain control module (PCM), the memory heat seat/mirror module (MHSMM), sentry key immobilizer module (SKIM), the transmission control module (TCM), the electro/mechanical instrument cluster (MIC), the optional overhead travel information system (OTIS), airbag control module (ACM), optional antilock brakes (ABS), the radio and the optional automatic temperature control (ATC) display head. The (BCM) is operational when battery power is supplied to the module, ignition switch power is needed for ignition switched functions. The body control module provides the following features: Automatic headlamp and fog lamp A/C switch status/evaporator temperature status BCM diagnostic support Central lock and unlock (VTSS only) Climate Control (Automatic and Manual) system support Door ajar switch status Door Lock Inhibit (key in ignition or headlamps/park lamps on) Electronic Odometer Support Fog Lamp Control Headlamp multiplexing control Headlamp, Park & tail lamps with battery save feature Headlamp Time Delay Illuminated Entry with “fade to off” Interior lighting with battery save feature Mechanical Instrument Cluster (fuel level, dim data, odometer & warning chime) support Memory system (LHS and 300M) Overhead travel information system Power door lock multiplexing control Rear Window Defogger Control Remote Keyless Entry with Panic Mode Remote power deck lid release Rolling door lock control (customer programmable) Sentry key immobilizer Speed proportional steering Vehicle Theft Security System Wiper Control (speed sensitive with return to park) The BCM receives information over the PCI Bus from the PCM in order to support certain features. The required information is as follows: ² Engine RPM ² Engine Temperature ² Injector on Time and Distance Pulses ² Vehicle Speed ² Charging System Failure, Engine Temperature Limp-In, VTSS Arming Status ² Engine Model ² “Check Engine” lamp status The BCM provides the PCM with information on the A/C switch status, battery temperature which is determined by the ambient temperature sensor and the “OK to Start” or VTSS status. If the BCM is replaced, the VTSS must be enabled in the new BCM via the DRB lll®, in order to start the vehicle.
COMMENT by , August 31, 2010
Thanks. I have had a mechanic trying to tell me the ingnition switch (electrical parts) is bad. I have more symptoms than the position on the switch is identified with.
ANSWER by , November 16, 2010
You're talking about the car's computer module or brain. What you've been told is true. If the computer is going bad, it must be replaced with a new one, a used one will not work. This happened to my car and my mechanic couldn't fix it; I had to take it to the dealer. They have to reprogram the new computer to match all the information in your old computer. This repair runs around $750 where I am from.