# BCM EEPROM Goodness or How to add OEM remote start



## thebac (Jul 29, 2017)

Very interesting information.

So you're a Pharmacy Tech who has an Electrical Engineering degree? Pretty cool. 

You remind me a lot of a guy I know thru the Duramax community. He's researched many of the same things for our trucks and came up with a lot of add-ons and mods that way.


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## StLouisCPhT (Sep 13, 2015)

LOL! The only "degrees" I have are my high school diploma and pharmacy tech certification.


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## Snipesy (Dec 7, 2015)

Nicely done.

Things like VIN, Serial Numbers, etc, are almost always stored in a section of the cache that can be rewritten as you please. That is... There's no signature or checksum or anything like that.


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## ChevyGuy (Dec 13, 2014)

Seems like a reoccurring pattern. Stuff that gets changed has it's own storage separate from the software. Probably to prevent the software from getting overwritten.


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## StLouisCPhT (Sep 13, 2015)

It also applies to the instrument panel. There is a distinct size difference in this chip and the one in the silverboxes. That chip was a 16k and this one is only a 2k.


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## StLouisCPhT (Sep 13, 2015)

And, the test is a success. I now have oem remote start 

To add it you just need the following items:

1) BCM programmed for remote start (opt BTV)
2) hood latch for 2012-15 Cruze/2016 Cruze Limited (part number 95463828)
3) 5 button key fob w/ remote start function

How to:

1) Get your bcm reprogrammed* and program your new fobs to your vehicle. Optionally, you can use an onstar module already programmed for remote start instead of new key fobs. It is a straight switch out, but you will need (at the very least) the free basic onstar plan to have access to the key fob section in the my chevrolet app. Unfortunately, I have no idea how to tell if one is already programmed for it.

2) Replace your existing hood latch with the new one. Don't forget to reconnect the wire harness.

3) Use your key fob or onstar via my chevrolet app to test the remote start.


*-At the present time, I do not recommend doing a BCM swap with a unit already programmed for remote start. Even though the eeprom clone will allow the new unit to pass the anti-theft systems, it can cause issues with other parts in the vehicle.... especially if you have a 2011. Unless Chevyguy, dhpnet & I can put our heads together and come up with a solution, you will have to either use a 3rd party reprogramming service or convince GM to enable the BTV option for your vin so a dealer can do the reprogram.


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## Blasirl (Mar 31, 2015)

HowTo: please!


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## StLouisCPhT (Sep 13, 2015)

I reverted back to my original bcm due to 2 issues that may or may not be related to each other:

1) I can't set my cruze control while using the 2014 cruze bcm (The vehicle I pulled the test bcm from does have cruise installed w/ the same rpo code as my 11, and it can be turned off and on... just not set)

2) the a/c is dead set on frying me alive no matter what I do, even a battery reset (obviously a conflict with the 2011 hvac control module's programming and the test bcm)

Before anyone suggests replacing other parts, etc... remember, this was only a test to see if remote start could be added by doing a bcm swap + eeprom clone instead of having your original bcm reprogrammed.

Also, it seems that it should be possible to add the remote start without buying a new hood latch. The first thing I encountered after reinstalling my original bcm and starting my car was a warning message that my hood was open. Apparently the only difference between the 2011 hood latch and the 2012+ hood latch is the wiring for the switch. If someone else wishes to experiment with changing the wires around to see if they can get remote start working that way, let me know and I will gladly loan you my test bcm.


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## Snipesy (Dec 7, 2015)

I would try to divvy up the segments in the BCM.

Generally at the end or start of each segment will be some numbers specifying where it is, what the part number is, etc... You can then identify the ones you want to keep and update. It might even specify how big the segment is.


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## StLouisCPhT (Sep 13, 2015)

I'm not sure I understand what you mean by divvy up the segments?

1) Physically the BCM is a single motherboard with 6 connector plugs soldered on. There aren't "segments".

2) Software wise, there aren't segments. It LOOKS like there are, but when you compare reads between units or different reads for the same unit after something was changed you'll see that even in the blank areas there are random changes without an indication of what they relate to. The other issue is that while the vin, serial number and (possible) security code are in clear text everything else is encrypted and comes up as gibberish.


I got the HVAC working more or less properly by turning my temperature knob to dead center then pulling fuse 17 from the internal fuse box for 30 seconds to force a recalibration. I'm not exactly freezing now with the ac on but I'm not melting anymore either. Not too concerned about the cruise control not setting.

All this being said, the testing I have done has met my original goals and I will not be working any further on this project.


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## StLouisCPhT (Sep 13, 2015)

okay... so here is the final tally.

Swapped original BCM with one already programmed for remote start, check
Installed replacement hood latch, check
Had Brake Pedal Position Sensor calibrated (needed after swapping bcm to re-enable cruse control), check
Replaced original 4 button key fobs with new 5 button key fobs, check.

Price:
used bcm & used latch ($35 together) + new pair of fobs ($50) + sensor calibration ($75): $160

vs

sending original bcm out to be reprogrammed ($249) + used latch ($5 to 10?) + new fobs ($50) + inability to use vehicle while bcm is removed: at a minimum $300, more if sensor needs to be recalibrated after bcm is reprogrammed.

vs 

3rd party remote starts that do not have 100% functionality with Cruzes: not sure, I heard too many complaints about programming and key fob issues to even look into them


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## Snipesy (Dec 7, 2015)

StLouisCPhT said:


> 2) Software wise, there aren't segments. It LOOKS like there are, but when you compare reads between units or different reads for the same unit after something was changed you'll see that even in the blank areas there are random changes without an indication of what they relate to. The other issue is that while the vin, serial number and (possible) security code are in clear text everything else is encrypted and comes up as gibberish.


When you program them, It is segment by segment. It may not be obvious, but they are segmented.


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## lonewolf04 (May 6, 2016)

Now to figure out how to expand on this to get a manual transmission to work with it... hmmmm.


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## StLouisCPhT (Sep 13, 2015)

Sorry I took so long to reply to this. You'd probably have to put in some kind of safety switch for it to work.



lonewolf04 said:


> Now to figure out how to expand on this to get a manual transmission to work with it... hmmmm.


I finally tracked down a 2011 Cruze with remote start. If I can get the hood latch from it, I'll see if it uses the same part number as the 10-11 Equinox.


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## StLouisCPhT (Sep 13, 2015)

I just had some more fun with this project. I updated my original 2011 BCM with the newest calibrations & software available using the VIN of a 2011 Cruze with remote start through the AC Delco TIS system. It definitely updated my BCM, as installing it provided me with an actual configuration setting through my radio to enable/disable remote start. With a 2014 Cruze remote start compatible hood latch installed, it would not work and my car would report the hood ajar. Switching to a 2011 cruze specific hood latch taken from a non-remote start enabled vehicle ended the hood ajar error and allowed remote start to function.

So here are the requirements to add factory remote start to a Gen 1 Cruze:

_2011 Cruze ONLY - a bcm pulled from a remote start enabled 2011 cruze, or your original bcm reprogrammed using the vin from a remote start enabled 2011 cruze and key fob(s) or onstar module programmed for remote start._

_2012-16 Cruze - a bcm pulled from a remote start enabled 2012-16 cruze, or your original bcm reprogrammed using the vin from a remote start enabled 2012-16 cruze, a remote start compatible hood latch (P/N: 95463828 or 42522220) and key fob(s) or onstar module programmed for remote start._


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## lonewolf04 (May 6, 2016)

StLouisCPhT said:


> I just had some more fun with this project. I updated my original 2011 BCM with the newest calibrations & software available using the VIN of a 2011 Cruze with remote start through the AC Delco TDS system. It definitely updated my BCM, as installing it provided me with an actual configuration setting through my radio to enable/disable remote start. With a 2014 Cruze remote start compatible hood latch installed, it would not work and my car would report the hood ajar. Switching to a 2011 cruze specific hood latch taken from a non-remote start enabled vehicle ended the hood ajar error and allowed remote start to function.
> 
> So here are the requirements to add factory remote start to a Gen 1 Cruze:
> 
> ...


So when you updated the 2011 BCM with new software for a VIN with remote start you didn’t get VIN mismatches?


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## StLouisCPhT (Sep 13, 2015)

lonewolf04 said:


> So when you updated the 2011 BCM with new software for a VIN with remote start you didn’t get VIN mismatches?


TIS doesn't actually care what VIN is used to program a part. You can let a MDI (or approved pass through device) detect your vehicle, but then change the VIN to whatever you want. I've used this trick to reprogram a Mylink radio from a 2017 Verano using the VIN of a 2016 Cruze Limited so it would work in my 2011. 

In the case of the BCM reprogram, I used the VIN from a 2011 Cruze LT so the difference between that car and mine would be minor and still be an official update of the BCM (mine is a 1LT Trim and the donor vehicle is a 2LT trim). The update did change the VIN registered in the BCM to match the 2LTs. A quick change of the VIN back to mine using the procedure in my original post took care of that issue.


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## Blasirl (Mar 31, 2015)

Just curious as to how you view the output. Have you tried filtering it using Hex or possibly octal?


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## StLouisCPhT (Sep 13, 2015)

Blasirl said:


> Just curious as to how you view the output. Have you tried filtering it using Hex or possibly octal?


I hate to say it, but I have no idea what you mean by that. Are you talking about reading the BCM eeprom to change the VIN? It's the same as reading the radio eeprom: in hexadecimal.


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## thebac (Jul 29, 2017)

Bringing this back up to ask, do you have to match the donor car's complete option package to yours (obviously other than remote start) when swapping the BCMs or doesnt that matter? 
We recently bought our daughter a 2012 Cruze LT that doesnt have remote start, and I want to give this a shot.


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## thebac (Jul 29, 2017)

Ooooo-kay, I'll ask it a different way. Does the new BCM with remote start need the VIN changed thru programming or the eprom trick, or is it pretty much plug-n-play as it sits?


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## Doorev800 (Mar 11, 2019)

I just did it this weekend. Pull your original bcm and read and save the eeprom. Then take the doner bcm and program just the eeprom with your info. Then plug it in and you are good to go. It is plug and play...everything worked the same as the original just have to get myself some key fobs and I am good to go.


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## thebac (Jul 29, 2017)

Thanks. I had a feeling it would be like that. Let me know what hoops you had to jump thru to reprogram the fobs.


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## StLouisCPhT (Sep 13, 2015)

Reprogramming the fobs is even easier than upgrading to remote start.


Insert master key into ignition
Switch ignition ON
Switch ignition OFF
Remove master key
Within 10 seconds insert new key and switch ignition ON
New key now Programmed
NOTE: A maximum of 8 keys can be programmed


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## thebac (Jul 29, 2017)

Finally got my eeprom software to work, trying to figure out what chip StLouis was talking about. I found two 8-pin chips, one on the "top" of the circuit board over on the right hand side middle, and the second on the underside of the board in the middle. Which chip is it?


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## StLouisCPhT (Sep 13, 2015)

I honestly don't remember anymore. I do remember that the chip to read and flash was on a different side on my 2011 BCM vs the 2014 bcm I first experimented with. Are they both 24C16WT chips? You might have to just try reading both and see which one gives you the vin numbers.

Btw, I think reprogramming the fobs is a little more complicated than I posted above... but maybe my memory is a little biased as I did my reprogramming in a hurry because of a major t-storm suddenly appearing over my head at the time.


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## thebac (Jul 29, 2017)

I did attempt to read both. One had a lot of information, but no VIN. The other I couldnt read for some reason.


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## StLouisCPhT (Sep 13, 2015)

thebac said:


> I did attempt to read both. One had a lot of information, but no VIN. The other I couldnt read for some reason.


I’m not certain. Try posting or pming me some pictures of each complete side of your bcm.


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## firehawk618 (Feb 24, 2013)

Impressive thread.

I thought I was the only one who was fooling with eeproms in various modules.

I had tried to add auto driver window roll up on my 2018 Cruze RS / Diesel by using a VIN that had that option and that did work BUT my problem was I lost my DEF gauge in the process. Instead of reading the percentage of DEF fluid it just said OK.

I would be fine with that however when the fluid did actually get low I got no warnings and the other issue is my glow plugs stopped firing. The car would still start but I noticed when it was cold out instead of a second or two delay before starting it would just fire right up resulting in a rough running engine for a second......

The reason for this is that the only trim level you could get auto window up on a 2nd gen Cruze was the Premier and the Premier was never offered with the diesel engine.

**Also swapped driver door harness, switch and window motor


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## firehawk618 (Feb 24, 2013)

What I am going to attempt to do is figure out where the coding lives in my BCM, dump it, use a VIN from a Premier, flash it, dump it and analyze the differences.

Besides auto window up the Premier would likely also have auto HVAC and a few other options.

I would imagine the difference for each option would be a bit or two in code.


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## WillL84 (Aug 5, 2019)

firehawk618 said:


> What I am going to attempt to do is figure out where the coding lives in my BCM, dump it, use a VIN from a Premier, flash it, dump it and analyze the differences.
> 
> Besides auto window up the Premier would likely also have auto HVAC and a few other options.
> 
> I would imagine the difference for each option would be a bit or two in code.


Premier does have auto HVAC, at least mine does. Not sure if it's part of a package - like how mine didn't come with the "driver assistance package" which has the rear sensors, blind spot monitors, etc. Also didn't come with fogs but I just got the kit for Christmas - complete with the code to bring to the dealer to make them work - which I still think is 100% BS. Why not just turn that function on in all the cars so then it's just a kit install?


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## Sks (Jun 2, 2020)

StLouisCPhT said:


> In my quest to find a way to add factory remote start to my 2011 Cruze, (and my side quest for a cure for a bad case of boredom mixed with inquisitiveness), I took a look at a BCM pulled from a 2014 Cruze with remote start.
> 
> The first thing I did was immediately investigate the internals. It didn't take long to find an 8 pin 24C16WT sitting by itself. A quick google search revealed that it was the eeprom I was looking for.
> 
> ...





StLouisCPhT said:


> I hate to say it, but I have no idea what you mean by that. Are you talking about reading the BCM eeprom to change the VIN? It's the same as reading the radio eeprom: in hexadecimal.





StLouisCPhT said:


> In my quest to find a way to add factory remote start to my 2011 Cruze, (and my side quest for a cure for a bad case of boredom mixed with inquisitiveness), I took a look at a BCM pulled from a 2014 Cruze with remote start.
> 
> The first thing I did was immediately investigate the internals. It didn't take long to find an 8 pin 24C16WT sitting by itself. A quick google search revealed that it was the eeprom I was looking for.
> 
> ...



Hi there interesting topic , is there any way you can email me maybe i can discuss a project opportunity you can help me out seems like you have good knowledge on gm . [email protected]


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## Blasirl (Mar 31, 2015)

Smart Key Solutions


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## GregMelb (Nov 2, 2015)

Hi, I have read your post and am quite interested to know the detail of how you reprogrammed the Vin number in the BCM. 
What is the usb reader and adapter clip you refer to? Do you have special software to read it?,

What is the procedure to switch the vin to match that of my car?
Thanks again , a good read


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## GregMelb (Nov 2, 2015)

StLouisCPhT said:


> Reprogramming the fobs is even easier than upgrading to remote start.
> 
> 
> Insert master key into ignition
> ...


How do you program the push button start keys.


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## Blasirl (Mar 31, 2015)

GregMelb said:


> Hi, I have read your post and am quite interested to know the detail of how you reprogrammed the Vin number in the BCM.
> What is the usb reader and adapter clip you refer to? Do you have special software to read it?,
> 
> What is the procedure to switch the vin to match that of my car?
> Thanks again , a good read


How-To: Disassemble Radio To Program VIN


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## pinstripebob (Mar 30, 2017)

I got a donor BCM from a 2014 with remote start, but when I read it I don't quite get the VIN. I've tried changing what chip I'm using in the EEPROM software, but no luck getting a full (or mostly readable) VIN. I got the donor BCM from VIN 1G1PE5SB3E7240033, but the closest I can see is 2400 from the read. Any thoughts on how I could troubleshoot this? The chip itself is an ST brand 24C16WT, although any combination of manufacturer and chip in the EEPROM software seems futile. I've included a screenshot of what I get using the settings in the MyLink thread. Thanks!


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## Blasirl (Mar 31, 2015)

@StLouisCPhT


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## plano-doug (Jul 1, 2015)

pinstripebob said:


> I got a donor BCM from a 2014 with remote start, but when I read it I don't quite get the VIN. I've tried changing what chip I'm using in the EEPROM software, but no luck getting a full (or mostly readable) VIN. I got the donor BCM from VIN 1G1PE5SB3E7240033, but the closest I can see is 2400 from the read. Any thoughts on how I could troubleshoot this? The chip itself is an ST brand 24C16WT, although any combination of manufacturer and chip in the EEPROM software seems futile. I've included a screenshot of what I get using the settings in the MyLink thread. Thanks!
> <snip pic>


Perhaps there is another menu choice for a 24C16. I'm wondering if there is an address issue - the 24C128 uses 3 more address bits than the 24C16.









BTW, if I did this correctly, the entire ascii VIN converted to hex is:
1G1PE5SB3E7240033
31 47 31 50 45 35 53 42 33 45 37 32 34 30 30 33 33​
HTH.

Doug

.


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## pinstripebob (Mar 30, 2017)

I think the software I was using was limiting me. I downloaded AsProgrammer, was able to choose _24C16_, and sure enough I can see the donor BCM's VIN in its entirety. I suppose the next step is to pull my wife's BCM and read it, see what it looks like.

I used information and software found here: Dumping Firmware With the CH341a Programmer - Black Hills Information Security

I'll go ahead and make a backup of the donor BCM's data, might try changing its VIN to my wife's and see if I can plug and go. Below is a screenshot of the success:


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