How to reprogram BCM?
 

Just replaced my BCM and currently experiencing a column lock symptom. I thought I read somewhere that you could manually reprogram the BCM so that you could drive your car down to the dealership if you needed to have it reprogrammed. Anyone have any good links or know what to do? I can't seem to find anything through my searches.

No you can't do that without a TechII I believe. Call the tow truck!

If it is a security issue you have to relearn the key security codes...
Is this a used BCM? I have done 2 BCM replacements I will see if i can find the procedure..
I did have to take one to the dealer to remove the active handling feature that my car does not have.

You are correct that there is a manual relearn procedure which I don't have, but it is posted in here somewhere. What it does is allows the secured password that's shared between the PCM and BCM to be relearned which will do exactly what you need, allow the car to start and run to get it to a dealer with a Tech2 where the RPO codes can then be programmed into it. Use the search and you will find it....its here somewhere.

Is this what you need?
http://www.hptuners.com/forum/showpo...72&postcount=5

or

http://www.c5help.com/c5_no_start.htm

The ONLY way to access the BCM is with a TECH II. The only changes that can be done are installing or removing GM RPO codes to support factory or dealer installed options (ie the F-45 Real Time Dampening)

dougbfresh provided you procedures for syncing the BCM / PCM passwords.

That will get the car to run but,,,it will NOT address any RPO codes that are no longer supported. You will know if there are issues because they will either NOT FUNCTION or you will have No Comms DTCs.

If you have column lock issues, thats a security related problem or a Column Lock circuit failure.

Get the BCm issues sorted out and then work on the column lock. Is your steering wheel locked ???

The 2 mph speed restriction (fuel cut off can be addressed via the PCM using EFI Live or HP Tuners. You remove the sucreity related fuel cut off via a table.

Bill

Bill

Where are you located ? I have a Tech2 that can fix problem if you're local.

I'm in the King of Prussia area of PA.

Located in UTAH. Thanks for the offer to help reprogram.

dougbfresh, thanks for the links. They worked out great. Got the car started. Now I need to get the column lock issue figured out.

Corvettes of Houston sells the best column lock kit.

So, what does everyone think is my problem? After reading the forum below, it seems that when I replaced my BCM with one from a salvaged unit, the pallet in my key is now wrong for the unit. As a result, the security system is locking me out by killing the motor if I go faster than 2 mph. So, would taking it the dealer fix this issue? Is there anyway to bypass this 2mph so I can drive to the dealership? The car runs just is stopped by the 2mph. I can't be sure, but I don't think my column is really locking on me. I'm wondering if someone did the CLB already. I'll check tonight. If not, I'm buying one tonight. Would it be the consenses that reprogramming would take care of all issues?


http://forums.corvetteforum.com/c5-t...m-running.html

Try this:

BCM/PCM RELEARN PROCEDURE


You will need to conduct the PCM/BCM relearn process. This matches their handshake ID's and allows them to talk to each other.

Do this before you worry about VATS issues:

1. Turn on the key for 11 minutes.
2 Turn off the key for 30 seconds.
3. Repeat 1&2 two more times.
4. Turn on the key for 30 seconds.

The car should start and run with the new BCM. Good luck and report back on your progress.
Shirl
SD Racing Enterprises
Aguila, AZ
Coutersy of MrEracer


This will sync the PCM to the New BCM but all of your RPO options will not be retained. You will need a TECH II to program them into the new BCM.

Bill Curlee

I did do this procedure and got the car to start. When I first put my BCM, it wouldn't start at all. After I did this "relearn" step, the car started but won't allow me to go over 2mph. Any thoughts on bypassing the 2mph fuel cut to get it over to the dealer.

Get somebody with a programmer that can change the fuel cut-off speed to 200 mph.

8-23-09 Update.

Car is up and running. Thanks for everyone's help. I have to especially thank Chuck (8Vette7) for walking me through fixing my issue.

Car was a 99 with the 6spd. My car's BCM got wet and I replaced it with a used one. After I relearned the PCM to the BCM, the car started but then I got the CL failure. I pulled everything apart and found that I had a K-harness installed. As part of the GM recall, this harness was installed and I believe the locking mechanism was deactivated as I could turn the steering wheel with no key. Also the 2mph fuel cut was programmed in. To fix the issue, I disconnected the K-harness, and installing the CLB. I had to get the CLB working, I had to pull fuses 25 and 29 for a minute. After that the car started right up. Thanks again guys.

i had put a new ignition switch and used the same lock cylinder and the C5 would not start the code is 40- BCM B2723 HC do i have to get a new BCM or just get it program and only a dealer could do it

NO! The VATS circuit isnt working. Are you sure that you connected the small VATS black jacketed wire when you replaced the switch??

You can see it in this picture. It goes to the small metal can (sensor) on the front of the key cylinder. Make sure it plugged in properly!!!


Attachment 48179915

yes i did all that. At this time i am now changeling the lock cylinder because i had some trouble with the key

If you received a NEW key,,,,,, was the pellet resistance the EXACT same value as your old key pellet???

same key

Hmmmmmmmmmm,,, If all you did was change the lock cylinder, read the key resistance and note it. Then insert the key in the ignition, disconnect the chip reader cable and read the resistance of the key THRU the harness that comes off the sensor. It should read almost exactly the same as the key chip read.

If it does, make sure the male and female pins in the tiny connector are making the correct contact and are NOT damaged.

BC

BC