New Key required? passkey3+

[Jesse C]

Hi!

 

I'm digging through search results, and will probably find the answer eventually, but anyone have a quick answer...

I have a used ECM from another truck that I've run the replace and reprogram ECU function on, so it has the correct VIN for my truck (2009 Sierra)

I also have a new TDM.

When I put in and turn the key, the security light just stays on.

Checking tech2 (clone), it says Key Valid: No (amongst a bunch of other things)

 

Do I need to buy a brand new master key for the truck before I can proceed, or can I use this one?

Do I need to sync the TDM to the ECM first before syncing the key to the TDM, or is it the other way around?

 

Also, how do I sync the TDM to the ECM? It doesn't appear to be obvious in the tech2 options, but maybe I missed it.

 

Thanks!!!

[tbarn]

Why a new tdm and newish ecm? What started this?