So... prior thread was getting "messy". Thought I'd start fresh. 2005 BCM DTC B1000, BCM has an "internal error" and won't allow you to train BPP so no brake lights. Finally get ahold of a 2007 BCM. Install and flash it with 2005 software via TDS. Everything seems fine except for VIN in BCM doesn't match and the EBCM just doesn't like it. So, send off to have the vin "cleared/virginized". Reinstall again & set up, vin now updated just like it was a new unit. Set the configuration for the car, and have to mess with a few things to get all the errors to clear. Radio, EBCM, memory were being a bit fussy but finally all good. Test drive and shut down several times without issues. Send my buddy home with his car, everyone is happy.

Calls today, after sitting a couple days the TCS errors are back & no brake lights again. I will have to drive the 30 min to his place with tech2 to see whats up. But I'm expecting the damn BCM has lost it's configuration again. That was the issue right after reinstall. After some time it would "forget" it has a manual trans?!? Anyone seen anything like this? No errors with the BCM itself, just looses its setup?

I'll update after I get the details on whats happening. Hopefully in a couple days.

Thanks!

 

Good Luck. I just had help from Dano523 to help me with setting up the TIS2000 in my GM VCX Nano. If you have issues, reach out to him. He will be able to help.

 

I'm not knowledgeable on the subject, but from all my research I thought the BCM part numbers have to be identical to the unit currently in the car. For example I couldn't put a bcm from an 08 into my 07 because they are different part numbers.

 

More than mildly curious as to how or with what app the BCM can be modified, and to what extent. I had heard it's not something that is pursued bc of the associated liability factor???

Would love to be able to modify the BCM in my restomod project...

Nick

 

Very interesting thread, thanks for sharing. In for the fix.

 

On brake lights, would do another brake pedal Relearn (only light pressure on the pedal until you just get the pedal to firm up on the press, so the BCM learns that ohm value), and maybe take a look at the sensor plastic forks for wear, and maybe time to change the switch. Also, pull the rear inner right had side rear break light, and take a look at the rear loom connector in the rear bumper void area for corrosion as well.

U error is often a corroded wire pin or broken wire, so when you installed the BCM, did you make sure to clean both the the BCM pins, and the connector side as well.

As for TCS, pull codes to point you to problem of which sensor may have a connector problem at that end, and again, could be that bcm connectors are not clean and they alone causing the problems.

 

Ok, finally had a chance to drive the 25 miles to friends car & confirm what is happening with the BCM... It appears that the configuration/setup is not "staying". When I connect my tech2 I am able to set up the BCM as new (no error of a locked BCM VIN). Everything sets correctly & looks good. No errors anywhere, car starts & drives but after about 1/2 hour sitting the VIN, BCM RPO setup & BPP settings are back to factory. This is a manual trans car & when the BCM resets, the RPO reverts to Auto Trans & no HUD. This freaks out most of the other modules as they are not able to talk/communicate with the non-existent auto trans & the Vin number being cleared causes the EBCM to error with a configuration error and BPP is wrong so no brake lights. Fun huh.... not.

I've reached out to the vendor who "virginized" the BCM for me as I want to discuss some options that I am considering. I will update when I have relevant news.

PS. After I set up the BCM/RPO/BPP I do a DTC check & clear all the errors. All are communication loss to auto trans or EBCM to BCM. Nothing serious. I then power off the car for a minute or so & then power back up, recheck all systems for DTC with Tech2. Everything seems fine. Let the car sit & after about 1/2 hour-45 min the BCM is reset again.

 

Minor update, sending old BCM & this replacement back to vendor to "copy/clone" old info to the new. This involves removing the chip from each board as you can NOT write to it "in circuit". After looking at the file on the replacement BCM closer it appears that the data is off set incorrectly on the chip. We "believe" the vendor I got the BCM from may have tried to clear/update "in circuit" and corrupted the file. I'll update after I get both BCMs back & try this one more time.

 

Another update... So, got the BCM back again & installed in the car... With supposedly the correct file burned on the BCM I STILL get the exact same issue. Tech2 can set up the BCM with correct VIN # & RPO settings. It's all good for about 1/2 hour to 45 minutes & then the BCM resets itself somehow back to NO VIN & RPO back to auto trans & no HUD. Car is basically useless...

I had a 90 day warranty from the vendor who sold us the 07 BCM & they NOW have an 05 in stock. They are going to exchange it & I will then send it off to the same vendor (hope that isn't our issue) and have the vin cleared. Hopefully before the end of the month I will have another update...

Merry Christmas everyone & f... the GM engineer who designed the early C6 BCM.

 

Afternoon,
Final update here & I am going to post in the for sale area (which I HOPE is alright) to offer service to repair failed 05 BCM. I ended up buying the tools/software to read/write the EPROM chips & was able to source NEW EPROMs from Malaysia. The 05 I was working on again had a B1000 DTC error. Which is basically, "internal fault, replace BCM".

The EPROM was basically failing, or at least not responding as expected. New chip w/ the binary file copied directly from the old chip & the car has been flawless for 2 weeks now.

Cheers!

 

Hi Martin! Send me a message back about purchasing a new chip from you my friend.

 

This is the exact problem I would have!

 

Note sure if its a change to TDS and why they have DPS out in the wild to re-vin modules now since TDS may not being doing it anymore, but don't have problems with Tis2000 learning car vins to used units when flashing them into the cars with it.

 

Just a quick update. I've now fixed two (2) different 2005 BCMs with the B1000 error.... I'm sure the count will go up once word gets out.

 

would this repair be the same all the way up to 2013 BCMs?

 

Not sure... I've only had a couple of 05 & an 08 BCM apart to inspect and the chips were the IC was the same on them. The dumb B1000 error is pretty generic for an internal failure & the FSM pages are brief & only say, "replace BCM"...

 

I am dealing with the same issue on my 2005, I have the b1000 code and no lights when braking. I have the VCX nano and I tried doing a break pedal relearn. It fails when I attempt to do this. Please message me what you charge to fix this!

 

There are currently a handful of reconditioned 2005 BCMs on Ebay for sale starting at $250. Part number is 19473709.

 

is this the correct part # for the manual BCM?

 

This is the part number for a GM reconditioned BCM. Once installed it must be programmed.