Not only GM, dey all do dis. Why are you using all those separate warning beepers, already have a radio with speakers, use this instead. Most expensive thing is the box you put this stuff in, use the same box. Has an audio amplifier and speakers, feed this signals into this.
Only problem with this money saving technology, when you lost your radio, lose everything, OnStar, XM, MP3 player, warning signals, hands free calls, programming, etc., oh, and the radio itself.
Not only the radio, use to have separate modules for cruise, AT control, ignition modules, and even the alternator voltage regulator, now all jammed in that ECU box. Instead of paying a couple bucks for an ignition module, have to replace the entire ECU.
Sure a round about way to find that radio code, breadboard the entire vehicles electronic system, also should have a logic analyzer that cost practically as much as a new vehicle to read those codes. Oh, that breadboard is only good for one radio.
Ha, would be easier to hack into the GM service web site to get that code. Also have to be extremely careful when working with EEPROM, stored in flashram, slightest amount of ESD, will delete it.
Love my wife, but like everybody else, new is better, LOL. Why I like this old stuff, easy to work on and cheap, other three vehicles, any radio will work, hundreds to choose from. Suspecting problems with the fuel regulator on my Supra, 30 bucks for a new one. Easy to replace, with this new stuff, mounted with the fuel pump, have to drop the tank, buy all that other stuff you don't need and lay our around 250 bucks!
All brass cooling system parts, can be cleaned with acid and repaired with a propane torch, new stuff, throw it away and pay $$$$ for new ones. Ha, not only the radio, but just about everything thing.
Ha, lost count on the number of times I was told by my dealers to trade if off for a new one. Would work for a little while, but then told to trade it off again.