I recently purchased an EFI Live. I proceeded to download the Allison TCU just fine, but I have tried to connect to download the stock ECU programming and it keeps saying it's locked. I tried enabling "try all keys" for all stock ECU codes, and it keeps saying it's locked. The truck runs stock, and I bought it two years ago. Since I restarted it, the security light stays on and the gauges randomly go back to zero. The radio also appears to not be doing anything. Is this likely a situation where I need to disconnect both batteries and reset the ECU? Has anyone ever had one locked out? This is also my first time reading an ECU. Do you have to register the VIN before downloading your tune? I have not taken this step yet. It didn't stop the TCU from downloading though. Any thoughts???

Ok, so a quick update: I found that most issues were with resolved with disconnecting the battery cables. But, I tried to read it again and got this output
:21:04:28.125: Scanning for EFILive FlashScan V2 HAPI
21:04:28.140: Autodetect interface ...
21:04:28.171: Interface firmware version: 2.6.6
21:04:28.171: Connection to [FSV2] interface is OK
21:04:28.187: CAN-VPW Bridge Activated
21:04:28.203: Current protocol set to: "SAE J1850 VPW"
21:04:28.203: Autodetect PCM...
21:04:28.250: Connection to PCM is OK
21:04:28.250: Autodetect TCM...
21:04:28.296: Connection to TCM is OK
21:04:28.296: Current protocol: "SAE J1850 VPW"
21:04:28.312: Interface firmware model: FSV2
21:04:28.328: Interface firmware version: 2.6.6
21:04:28.343: Interface firmware date: Dec 14, 2008
21:04:28.343: FlashScan serial number: 003751696878
21:04:28.359: FlashScan license number: 003751696878
21:04:28.406: Request GM VIN...
21:04:28.515: VIN: 1GCHK29113E112978
21:04:28.515: Request serial number...
21:04:28.609: Serial number: 2204M00C2154
21:04:28.609: Request hardware number...
21:04:28.671: Hardware: 12209950
21:04:28.671: Request GM operating system...
21:04:28.703: GM operating system: 15189044
21:04:28.703: Request GM NVM...
21:04:28.734: GM NVM: 15189043
21:04:28.734: Request GM Engine calibration...
21:04:28.765: Request GM Engine diagnostics...
21:04:28.796: Request GM Transmission calibration...
21:04:28.828: Request GM Transmission diagnostics...
21:04:28.859: Request GM Fuel system...
21:04:28.890: Request GM System...
21:04:28.937: Request GM Speedometer...
21:04:28.968: Request GM BCC...
21:04:29.000: GM BCC: DTLZ
21:04:29.000: Request GM VAT/IGN Cycles...
21:04:29.031: GM VAT/IGN cycles: 0
21:04:29.031: Request GM oil life...
21:04:29.062: Oil life: 37
21:04:29.062: Query support for stream.01 scan mode...
21:04:29.250: Query support for stream.02 scan mode...
21:04:29.453: Calculating number of dynamic packet ID's...
21:04:30.015: Loading generic configuration file: sae_generic.txt
21:04:30.015: User defined calculated PIDs file: calc_pids.txt
21:04:30.015: Enhanced configuration file: gm_enhanced.prn
21:04:30.578: Request GM VIN...
21:04:30.671: VIN: 1GCHK29113E112978
21:04:30.671: Request GM operating system...
21:04:30.703: GM operating system: 15189044
21:04:30.718: Validating PIDs...
21:04:30.875: Validating Modules...
21:04:30.890: Initialising PIDs...
21:04:31.031: Initialising Modules...
21:04:31.093: Ready.

21:05:16.328: Disconnecting ...
21:05:16.703: CAN-VPW Bridge Deactivated
21:05:16.703: Disconnected
21:05:16.937: Loading generic configuration file: sae_generic.txt
21:05:16.937: User defined calculated PIDs file: calc_pids.txt
21:05:16.937: Enhanced configuration file: gm_enhanced.prn

So... Any ideas on what it could be? It comes up and just says that there's an error. After I reset the ECU, it didn't say it was locked, but just gave a general error. Any ideas on what to try? I had the key in the first on position as opposed to IGN. The first time I tried it on IGN and that's when it said it was locked.

First needs to be in run position but no started.
You the only owner of the truck?
Have you tried other programmers and not fully uninstalled them?
If not the original owner maybe someone has done it and left it on it. So need to do a full flash of stock OS to allow access to it.

Brian

Ok, I was in the first key position, which I think is ACC on the '03. No I am not the original owner. I have never used any other programmer. The truck runs stock as well. UGH, I hear you need a tech II to reflash stock OS. Know anybody with one? Obviously I'm gonna try a little harder before I resort to mailing out my ECU. haha Do you have to plug the scan tool into the obdII port before the laptop, and then load the software or what is the correct loading order?

And there it is... :) Yeah, just changing the sequence to: IGN->V2 to OBD->V2 to Laptop-> Open EFI tune did the trick. :) Now to start to play, and use those skills that this Engineering degree piece of paper says that I have... lol

OK glad you got it figured out. It can be tricky sometimes on sequence. I forgot the V2 had to be plugged in and USB fully synced before opening EFILive Tune software if I want to do a full flash instead of a standard flash.

Have fun.
Brian