VATs question

[Cougar281]

How does the VATs relearn work? Does the ECM get a "Password" from the BCM, thus allowing the engine to start, the BCM get a "Password" from the ECM, or do they make up a "Password" and share it between them?

[GMPX]

BCM has the master password, the ECM 'learns' the password.

[Cougar281]

Then is it possible for more than one ECM to be married to the BCM so if swapped out, they won't have to be relinked?

[nevinsb]

You can disable the security {G1201} Anti Theft Configuration.

[Cougar281]

You can disable the security {G1201} Anti Theft Configuration.

Yes, I realize this. ;)

I like to learn "How Stuff works".

[Biodiesel66]

Then is it possible for more than one ECM to be married to the BCM so if swapped out, they won't have to be relinked?

Yes! As long as you don't reset the relink in the ECM and it's learned the BCM password. You can have as many ECM linked to the BCM/vehicle as you want.

Plug and Play.

[mr.prick]

You can disable the security {G1201} Anti Theft Configuration.

This is not a cure all for VATS.
Some vehicles have the fuel and ignition directly tied to the BCM
and unless you rewire these the BCM is going to dictate whether or not
the vehicle starts.