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Discussion Starter #1
Hi all,

So I was thinking about getting a replacement BCM, since my mechanic was so nice to me, I decided to see if I could help him out with a Cobalt he has in his shop.

He will be replacing the BCM, his problem is the Anti-Theft system will not let him start the car, I had this issue when somebody attempted to rob my Cobalt, so since I love my Cobalt so much, when it was at the dealership I stayed with it. After they soldered all the cut wires back into place, I saw the re-learn procedure, I peeked at their instructions on their computer in the service area, it was called "Learn New Key", or something like that. They never got it done while I was there, but they were working too many cars at once, maybe they messed up a part of the procedure. The next day they got it working.

The re-learn procedure was something like power on (but do not attempt to start engine) 10 or so minutes, then turn key to off, then repeat the procedure a few more times, then power on for 30 seconds, then finally attempt engine start.

This information could be very useful for those replacing BCM and want to replace and reprogram them themselves.

Thanks for any information.
 

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Theft deterrent module is different from BCM as far as I know.
 

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Discussion Starter #3
My mechanic let me try his spare BCM the junk yard borrowed him, when I connected it, I got the security light and I could not start my Cobalt. He even told me this before I tried. He said, the Key pass code (thingy, whatever it is) is passed through the BCM, then passed on to the ECM, where the final part is in the ECM where it allows the voltage to be sent to the starter.

Do you think you could browse the server for such a procedure?

I know one exists, seen it myself, but that was a long time ago.

Thanks in advance :)
 

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The procedure you described is for TDM programming if you replace module or key. This procedure has nothing to do with BCM. BCM reprogramming is done with Tech2

 

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Discussion Starter #5
The TDM been the part which reads the key?

Or the cylinder part in the center of that image?

When they did this, they didn't touch my cylinder at all, nor replace any parts.
(I know because they bent up the key insert hole, its still there. Also, they said the $700 was pure labor.
 

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The part that says TDM is the TDM and that is what reads the key.
 

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Discussion Starter #7
I'm not sure if that was replaced or not, the cylinder itself was not replaced, they didn't tell me they replaced any parts, didn't charge me either.

Anywho, what is the procedure anyway?
 

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Discussion Starter #9 (Edited)
Hmm,

Both would be nice, lol :) (Since we're talking about ECM, that would be best, however security light comes on with new ECM, to the TDM may be helpful too)

A copy / paste job would be fine, its good to know for any Cobalt owner
 

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It would take too much of my time to list all procedures plus unless you have a Tech2 and know how to use it, it is useless anyway. The manual for the Tech2 has 628 pages. I have it in pdf. Different years, even Canadian cars have different procedures. Cars within the same year have different procedures. Not to mention models with SC or TC.
 

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Discussion Starter #11
Okay, that's cool, don't bother with the BCM.

How about just the TDM then? :)
 

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Is your VIN the one ending in 3338? You still need a Tech 2 for the TDM.
 

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Discussion Starter #13
Yes 3338 is mine.

I didn't actually see the successful re-learn at the dealership, but the little peek I saw said something about just turning the key on a few times for certain amount of times.

But the above, I never saw success, maybe the dealer did use another method to reset the TDM, I don't actually know for sure.

I will get the information on the other Cobalt and post back its VIN so we can see if we can come up with a solution.

Thanks Coby.
 
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