99 300m int lghts-radio-locks stopped working bcm? is there a reset .dif bet prem and base bcm

Does it start an run ? Your best bet is to take it to a ASE certified repair shop ! All the things not working are controlled by the BCM body control module an are on the class 2 serial data bus , would be best to have hooked up to a factory scan tool to see if there are any DTC'S - diagnostic trouble codes stored . The instrument cluster gauge information comes from the PCM / ECM - engine computer over class 2 data bus .
The instrument panel cluster (IPC) displays the fuel level as determined by the engine control module (ECM). The IPC receives a serial data message from the ECM indicating the fuel level percent. The fuel gage defaults to empty if:
The instrument panel cluster (IPC) displays the engine oil pressure as determined by the engine control module (ECM). The IPC receives a serial data message from the ECM indicating the engine oil pressure. The engine oil pressure gage defaults to 0 psi (0 kPa) or below if:
The Body Control Module (BCM) performs multiple body control functions. The BCM can control devices directly connected to its outputs based on input information. The BCM evaluates this information and controls certain body control systems by commanding outputs on or off. The BCM control inputs can be:
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Sensors and switches that are directly connected to the BCM

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Class 2 serial data received from other control modules connected to the class 2 serial data link.

The BCM is also capable of controlling other vehicle systems that are not directly wired to the BCM. The BCM does this by sending specific messages on the class 2 serial data link. The control module capable of performing the required function will respond to the BCM message.
You best bet is to take it the dealer or a ASE certified repair shop !

try using a scanner tpo reset the CPU program in the ECM unit as it can become corrupted by the battery change.

check for blown fuse for int. lamps, locks fuse and 2 relays. do any locks work?

My 2003 started having issues with the speedometer and then odemeter and then guages, lock, lights, and then starting. I replaced the BCM (body control module) in dash behind radio and a/c contols. You'll probably break the plastic tabs getting it out but not a major issue. Had to have computor reset but all works fine. Keep track of part number on new BCM or vin from vehicle it was taken from for programing. I paid $35.00 for mine at salvage yard, 10 times that new.

First, there are three different sound systems available for a 2003 Oldsmobile Bravada. The wiring diagrams are completely different for each of them. The options are:

> Base Radio WITH Rear Seat Audio
> Base Radio WITHOUT Rear Seat Audio
> Preminum Sound Radio (seperate amplifier)

NONE of these systems have ANYTHING to do with the speedometer other than the fact that the Instrument Panel Cluster (IPC) gets its speed information from the Body Control Module (BCM) and all three of these possible sound systems also tie into the BCM.

The only thing I can guess is that your aftermarket installation is completely unable to communicate with the BCM as it is supposed to, and is also interfering with data communications between the BCM and the IPC.

The Powertrain Control Module (PCM) also communicates with the BCM and needs this information to control the engine and transmission properly. If you have engine control codes, I would recommend that you THOROUGHLY investigate and repair these before doing any thing else to your vehicle. Also, you need to scan the rest of the modules in your vehicle to see if it can be determined what is going on. I am willing to bet that your system is full of "U" codes, indicating network communications failures.

Given the amount of electronic's ( computers ) on your vehicle ,it could be a lot of thing's . Hooking up a factory or professional grade scan tool that can communicate with all the control modules on the vehicle should be the first step in the diagnostic problem . Checking for DTC'S - diagnostic trouble codes , communication between module errors etc.....
Your best bet , take it to a qualified repair shop that has the proper diagnostic equipment to check it out .
The power door lock system consists of the following components:
• Body control module (BCM)
• Driver door lock switch
• Front passenger door lock switch
• Door lock actuators in each of the doors
• Door lock system fuse into the BCM (BCM D 25A fuse)

BCM Functions
The body control module (BCM) is capable of accomplishing multiple body control functions. Components directly connected to the BCM are controlled by the BCM outputs. The BCM can control its outputs based on input information it obtains from sensors and switches that are directly connected to the BCM, or by receiving information from other vehicle systems connected to the class 2 serial data link. The BCM evaluates this information and controls certain body systems by commanding an output on or off.
The BCM is also capable of commanding other vehicle systems to control functions that are not directly wired to and/or controlled by the BCM. The BCM accomplishes this task by sending specific messages on the class 2 serial data link. The vehicle system capable of performing such function will respond to the BCM message.
The BCM controls/monitors the following functions:
• Audible warnings
• Indicators control
• Interior lighting
• Exterior lighting
• Power/automatic door locks
• Keyless entry
• Content theft deterrent
• Personalization
• Serial Power Modes
• Electrical Power Management

Buick Class 2 Operation Diagnosis 1998

What kind of place did the diagnostics ? Auto part stores ? The BCM - body control module . Takes a proessional or factory scan tool to pull codes from this module .
The body control module (BCM) is capable of accomplishing multiple body control functions. Components directly connected to the BCM are controlled by the BCM outputs. The BCM can control its outputs based on input information it obtains from sensors and switches that are directly connected to the BCM, or by receiving information from other vehicle systems connected to the class 2 serial data link. The BCM evaluates this information and controls certain body systems by commanding an output on or off.
The BCM is also capable of commanding other vehicle systems to control functions that are not directly wired to and/or controlled by the BCM. The BCM accomplishes this task by sending specific messages on the class 2 serial data link. The vehicle system capable of performing such function will respond to the BCM message.
The BCM controls/monitors the following functions:
• Audible warnings
• Indicators control
• Interior lighting
• Exterior lighting
• Power/automatic door locks
• Keyless entry
• Content theft deterrent
• Personalization
• Serial Power Modes
• Electrical Power Management

Hooking up a Tech 2 factory scan tool to see if the BCM will communicate would be the first step in diagnosing this problem ,also checking codes an to see if the scan tool can bidirectionally control the lock's window's etc.. I would suggest a buick dealer !

The locks don't work from any switch or just the driver's door switch ? The door locks are controlled by the BCM - body control module , that's were the clicking you hear is coming from there are no fuse's that are marked for the locks , fuse's for the BCM .

Door Lock System Components
The power door lock system consists of the following components:
• Driver door lock switch -- Uses a single signal wire for both lock and unlock switch activations
• Front passenger door lock switch -- Uses a single signal wire for both lock and unlock switch activations
• BCM -- Class 2 module which requires programming when replaced
• Reversible door lock actuators in each of the doors
• BCM PWR 15A fuse -- Located in the BCM fuse panel, supplies power for the door lock system

The BCM PWR fuse supplies battery positive voltage to the BCM for the door lock system.
The BCM supplies and monitors a reference voltage to the door lock switch through the door lock switch lock/unlock signal circuit. The door lock switch also receives a constant ground source. If a door lock switch is placed in the lock position, the reference voltage is taken directly to ground and the BCM senses 0.0 volts on the signal circuit. If a door lock switch is placed in the unlock position, the reference voltage is taken to ground through a 15k ohm resister that is internal to the door lock switches and senses approximately 2.9 volts on the signal circuit. This is how the BCM determines what portion of the door lock switch was activated.
The BCM, upon receipt of a door lock switch lock or unlock signal, will switch the appropriate door lock actuator control circuits to battery positive voltage. The opposing side of the door lock actuators are connected to ground internally within the BCM through the other door lock actuator control circuit and the doors will lock or unlock appropriately.
Vehicles without keyless entry have two internal drivers in the BCM to control the door lock actuators. All door lock and all door unlock. Vehicles equipped with keyless entry have three internal drivers in the BCM. Driver door unlock, passenger door unlock and all door lock. This is done to isolate the driver door lock actuator so it can be unlocked by itself using the keyless entry transmitter.

Body Control Module (BCM)
Lower center of the I/P, just below the HVAC control assembly

I will bet the check engine light comes on as well?

check the radio wiring