GM TheftLock reset through Tech 2

[Falcon_LS]

The CD player was not working on my '05 Envoy, so I picked up another unit from a '07 TrailBlazer. After installing it, the unit reads "LOCKED" so I borrowed a Tech 2 from a friend to try and clear the VIN stored in the headunit. Here is the sequence I went through:

- F0: Diagnostics
- 2005
- GMC Truck
- VIN Code S
- F1: Body
- Radio

Then I have an option for DTCs and unit information. How do I reset the VIN on the unit from there? I've been trying for the past half hour, but couldn't find it. Thanks!

 

[The_Eric]

Not too sure on that, as I have little experience with the Tech 2, but I seem to recall there being a menu for "special functions" or something to that effect. This is (I think) at the same screen as the Diagnostics... So, instead of choosing diagnostics, you choose the "special functions" instead. Now like I said, my memory is pretty rusty here, so forgive me if I'm off on the wording.

 

[Falcon_LS]

Sorry, forgot to mention, when I go to Special Functions, it attempts to connect to OnStar.

 

[The_Eric]

Do you have a menu for programming? Maybe it's in there?

 

[GMBoy]

If you have the UM8 radio the radio theft will have to learn the VIN. Without learning the VIN, the radio will display a locked message (LOC or LOCKED).
If the radio is replaced, perform a VIN Relearn, located in the Special Functions section on the scan tool. Cycle the ignition when complete. I have my Tech 2 next to me but no Trailblazer to connect to..but if memory serves me right..go to BODY and find the radio then special functions. Do not confuse it with the digital radio receiver because thats your XM radio only and seperate from your radio itself.

Otherwise, SPS programming is required....sometimes there are changes internal to the radio software between model years and they will cause you an issue that programming can sometimes correct.

 

[Falcon_LS]

Thanks for the input!

I have the UB1 radio with the UL8 option, and I believe the donor vehicle is the same. The part numbers on the radio label on the side, however, are different, although the connectors and everything else is exactly identical.

I just had a look once again, and only SPS is available under Special Functions under Radio. That tries to connect to OnStar.