Hi guys and gals! Newb to the forum! Heres the story: Wife lost the ONLY key she still had to her Lacrosse. (Thats a story in itself) So I got a new key made from the dealer, along with the instructions to program the key to the car. This is the 30 minute method. Well, the security light never went off after 10 minutes aftre multiple attempts, so to the dealer it went yesterday. Now the dealer says the BCM is bad since the scan tool wont communicate with it, BUT my question to him was it worked fine with the old key, so evidently the thing is communicating with something! So my question, can the BCM be bad, even though the old key worked fine, causing this new key to not be programmed?

im no expert on the dealer scanner but the bcm controls a bunch of stuff if it wasnt communicating with the pcm you would know it. so i would take it to a different dealer and see what they say without telling them anything about the first dealer and see if they have the same story

I agree.

Ahh...sounds like someone does not know what they are doing.
x3 on new dealer time!
PK3 does have specific parameters, so Its not uncommon for the DIY programming not work.
With no working keys, they may have to replace the TDM module -Theft Deterrent Module and completely reprogram new key to new module.
Make sure you get a second working key this time as well!
Always have one in back up, dont ever leave it to using the last one-Ouch $.
Best of luck John keep us posted what happens, hopefully at new dealer !

PS: At that dealer visit when you got the key cut, did the dealer attempt to then program the key for you or just told you to use the DIY Method?
From what I understand, The DIY programming only works when you have one original working key to program up a second one.

Yea the DIY method SHOULD only work if you have the original. You first insert the original to verify you have a working key then insert the second within x amount of seconds to reprogram. If it worked without the original I think we'd have a lot more stolen PK3 GM'*.