30-Minute Vehicle Key Relearn
Important: This procedure will only relearn the vehicle keys. This procedure will not learn the immobilizer prerelease password or the challenge/response data. Do not use this procedure as a substitute for a 10-minute relearn when replacing or reprogramming a TDM or ECM. Doing so will result in a failure to learn the prerelease password and/or the challenge/response data.

This 30-minute learn procedure should be used when all vehicle keys are desired to be replaced or reprogrammed. This procedure will erase all previously learned vehicle keys from the TDM. Once the 30-minute learn procedure has been completed, any remaining vehicle keys may be programmed using the Adding Keys procedure to ensure their continued functionality.

With an unlearned master vehicle key, turn ON the ignition, with the engine OFF.
Observe the security indicator, after approximately 10 minutes the telltale will turn off.
Turn OFF the ignition, and wait 5 seconds.
Repeat steps 1-3 two more times for a total of 3 cycles or 30 minutes.
Important: The TDM learns the key transponder information upon the ignition switch transition from OFF to ON. You must turn the ignition OFF before attempting to start the vehicle.

 

What is " immobilizer prerelease password or the challenge/response data ". Should I know, or care what that means? I assume that it means I CAN install a NEW set of keys, but throw away the old keys. Would I still need the Tech II scanner at a later time? What about the max limit of new keys that can be installed, something like 10 if memory serves?

 

No concern for an owner. Only for someone with a Tech II doing programming or replacement of a module.

If you ever lose all keys or someone steals the master key. You would follow this procedure. If you have a Tech II you don't need this procedure.

 

Chevy Mgr,
This all assumes that you have the new key cut to lock configuration. Once that procedure has been accomplished, would I then have to add my original key back into the system or would it still recognize that. If that all works then the $13.00 is all that one would have to spend to remedy the problem. That is not all that expensive then. Thanks

 

That is the way we were told to do it. I remember the on and off and watching for the info.