Tech II theftlock procedure?

BBSilverado · February 19, 2005

Ok, here is the problem. I put a used nav headunit in a friends Avalanche for him and it only works in the acc. position, when the key is turned to run the theftlock will engage and lock out the radio, Yes we know this would happen since he bought a used one.

The problem is that he took it to the dealer to get the headunit reprogrammed to his Avalanche and the tech tried but could not do it. My question is can someone provide the proper procedure with the Tech II thats needs to be done so we can give the techs at his dealership the procedure and he can get it to work.

Thanks for any help.

GM-Tech · February 19, 2005

This is strange. A radio that is theftlocked should not work at all. Not in accessory, not with the key on, not hotwired to a battery.

But then you didn't say what year the vehicle is or what model year the radio came from. Prior to 2003 (and some 2003's), there was simply a code that a customer could program into the radio. If power was lost for any reason, the customer's code had to be input to unlock the radio. If that wasn't available, we have a way to get the built in backup code out of the radio. If a code was never put in, it would never lock with a power loss.

Newer models no longer use that method. The radio actually learns the VIN of the vehicle. So if you just lose power, when it's restored, the radio compares the VIN it has with what's in the BCM and if they match (as they should), the radio does not lock due to the power loss.

If you have the above type radio, but you put it in vehicle that isn't of that type, you probably won't get it working.

So, what years are we talking about for the vehicle and the radio?

February 19, 2005

What is the procedure to install a new radio & learn the vin? My cousin is pulling the 6 disc head unit out of his '03 Silverado, I'd like to put it in my '04 Sierra, (I have the cassette/CD head unit) both are Bose systems.

Appreciate the help

BBSilverado · February 19, 2005

This is strange. A radio that is theftlocked should not work at all. Not in accessory, not with the key on, not hotwired to a battery.

But then you didn't say what year the vehicle is or what model year the radio came from. Prior to 2003 (and some 2003's), there was simply a code that a customer could program into the radio. If power was lost for any reason, the customer's code had to be input to unlock the radio. If that wasn't available, we have a way to get the built in backup code out of the radio. If a code was never put in, it would never lock with a power loss.

Newer models no longer use that method. The radio actually learns the VIN of the vehicle. So if you just lose power, when it's restored, the radio compares the VIN it has with what's in the BCM and if they match (as they should), the radio does not lock due to the power loss.

If you have the above type radio, but you put it in vehicle that isn't of that type, you probably won't get it working.

So, what years are we talking about for the vehicle and the radio?

<{POST_SNAPBACK}>

The vehicle we put it in is a 2004 Avalanche and it does not have the Bose system, it just had the AM/FM/CD with XM. The radio we put in is a 2004 Navigation radio (INR) part no. 10345735. It was from a 2004 Buick Rendezvous.

I did this same swap in my Silverado and it works perfect, but I used a brand new one and he bought a used one.

Like I said everything works great when you just turn the key to "acc". but when you turn to "start" and back to "run" the theftlock engages. If I disconnect the connector on the radio while the truck is in "run" and then reconnect it the radio will function properly untill the next time you cycle through the ignition. It appears the theftlock is only checked in the run position and only during initial startup.

any Help?

GM-Tech · February 19, 2005

I don't have a lot of luck with radio swaps like that. We even run into difficulties when we put in what looks like an identical radio, but one that has a different part #, when our AC Delco place says it's an alternate replacement #. Some of those don't even work and externally at least, the radio is identical.

I just went into TIS with a new truck's VIN to see what came up and this is what I got...

"NOTE: The navigation radio (RPO UM8) is NOT supported in Service Programming. "

If I had the vehicle here in front of me I could probably figure it out, or find out if it's even doable. Usually, when a radio is replaced in one of these newer vehicles, it has to be programmed. Since the nav radio is not supported in service programming... well, I don't know the procedure would be. I haven't even SEEN one of these radios in a truck yet so I don't have any experience with it.

Normally, if one just has a vehicle that has its original radio locked, you just hook up the Tech 2, go into Radio, then special functions, then radio setup. Then you can command the radio to learn the VIN and it will unlock. However, when a radio is locked, it's locked. Doesn't matter which way you turn the key, so I don't know what's going on with yours.

Swapping radios in these new vehicles is a whole new ballgame. My first step if I couldn't figure it out on my own would be to call Techline and tell them what I'm trying to do. Since it's supposedly not supported in service programming, they probably wouldn't be much help.

willieboy · February 20, 2005

How about you just put a toggle switch on the power feed. Once you start the truck, cycle the toggle switch, and it sounds like it will work.

jth7186 · February 20, 2005

I didn't swap a nav headunit, but did swap headunits and had a similar problem with the vin and ecm. The tech had to find a vehicle with the same type of new headunit, get its VIN and get the build-out info. Once he had that, he compared the build out codes to the ones on my truck and found which one(s) he needed to modify using the techII. He pulled the info from mine, went to the computer, loaded whatever he needed into the techII, went back to the truck and worked whatever magic he needed to with the techII and the headunit then worked fine.

I wish I had more details, but I can give you the name of the guy and the dealership if you want to contact him for more info...

BBSilverado · February 21, 2005

How about you just put a toggle switch on the power feed. Once you start the truck, cycle the toggle switch, and it sounds like it will work.

<{POST_SNAPBACK}>

The toggle switch trick didn't work when I switched the data bus wire or the power wire, switching the power wire would make it restart and it still locked up, switching the data wire did almost the same thing but without the complete restart.

engrb · March 18, 2007

check this out: I bought an 04 silverado at a dealership it had a PONTIAC (red display) radio cd, rds, etc. I wanted a factory looking radio i bought an 07 silverado radio from ebay cd, etc, it says LOCKED , i took it to the dealer no luck with tec 2 , i tried one from an older alero , rds,cd, cassette etc. it says LOCKED , the pontiac radio works !