Quote: Originally Posted by
cproaudio 
All S-10 trucks are NOT class 2 databus, even the 2003. GM doesnt use class 2 databus on every car, Only Chevys, Caddilacs, and GMCs. All Saturns, and Geo lines like the Prism dont have class 2 databus eventhough the radio looks like it. I dont even think that Pontiacs and Oldsmobiles are class 2. All class 2 radios will have door chimer built in. If you dont hear the chimer coming from the driver speaker then it's not class 2. I dont think RDS plays any role in class 2 databus.
On a class 2 databus radio, a single wire (thin orange wire) can do
01 ignition control. turn the key off and remove the key, the radio continues to play until the door's open.
02 illumination control. turn on the parking lights and the lights on the radio dims
03 door chime. GM got rid of the chimer circuit and built it into the radio. All warning chimes come from the driver speaker.
04 Onstar control. Allows onstar's audio to play through the radio's front speakers and mute the rear speakers
05 XM control. Allows controlling the GM XM satillite slave receiver. Audio is through the line input of the deck
06 various vehicle function control and programming. resets low tire pressure warning, oil change service warning, keyless entry programming
07 VIN number ID. class2 databussed radios are not interchangeable. They have VIN lock on it. You can't pull a radio out of an Impala and stick it in a silverado.
08 VSS controlled volume. The faster you travel the louder the radio gets.
The only cars that require relocating the radio are the ones that can control other functions such as Impalas and Monte Carlos.
You can take the following steps to determine whether you should relocate the radio or can pull it out completely when you're installing a new radio.
If your factory radio is 1 1/2 DIN 3" high then pull the radio out. If it's double DIN over 4" high then goto next step.
Place the key in the ignition or turn on your parking lights and put your ear next to the driver speaker. If you dont hear the warning chime coming from the driver door then you can pull the radio out. If you hear the door chime then goto next step
Press and hold the center button on the lower left knob for 30 seconds. If "SETTING" shows up then you HAVE to relocate the radio elsewhere with a relocation T harness. If "SETTING doesnt appear after hold the button for over a minute then goto next step
If you don't have Onstar or XM then you can pull the radio out but you will loose the chime. You will have to run an ACC wire to the fuse box or to the ignition wire. If you want to keep the chime you can use PAC part# C2RGM24. It also provides an ACC wire and retains delayed shut off. If you have either or both then goto next step
If you have Onstar but NO XM, you can replace the factory radio with an aftermarket deck by using PAC part# OS2. If you have BOSE then use OS2-BOSE
If you have XM and WITH OR WITHOUT Onstar and want to keep the XM then you have keep the radio. You can use the PAC AUX IN adapter # AAI-GM12 and relocate the aftermarket radio elsewhere. You have to use the stock radio for main volume control.
Class 2 Databus isnt as hard to deal with as some people said. I've never had any problem removing the radio or relocating the radio. I always follow 2 simple rules. 1 never disconnect anything when the ignition's on. 2, never disconnect any yellow plugs or looms then turn the ignition on. It's a good way to make the airbag light to come on and possibly deploy the airbag.
If I missed any combination then PM me and I will add it in.
I have a message about that and can even shed some light. What people don't know.
All GM vehicles from 1999 and up are Class 2 databus compliant, however, it is not well known at all due to GM doing something for several years in vehicles like the S10, and Pontiac Grand Prix. Vehicles like this had an E&C/Class 2 hybrid bridge. Sort of like those old network hubs that had both B&C and Ethernet. Anyway, this bridge was used mostly for older electronics and Onstar operation, as well as many other functions such as the tamper resistant digital odometer, automated communications and timing systems (lights, remote keyless entry and passkey theft deterrent, chime, and even ABS and airbag systems) and other systems. Most people did not know that these vehicles had class 2 due to the fact that in most books, it stated that the serial data bus was usually the E&C or the ECMs Data I/O. If you get a pinout diagram of your BCM, you'll notice 3 different serial data buses. ECM data bus, E&C data bus, Class 2 data bus.
Of course, this got redundant and GM decided eventually that the E&C was no longer needed. Also, if you ever wanted to tap into the class 2 to add a newer device (such as a newer GM radio), you can. Most Class 2 serial data bus radios can be used in another vehicle as long as they are programmed with that vehicle's VIN due to auto theftlock.
Someone proved this fact with a 1999 Grand Am (usually known as an E&C vehicle). The link to the thread is below:
http://www.gaownersclub.com/forum/sh...ad.php?t=93938
So don't be scared, it's there, and you may not even know it.
Starflare5.
.
The Class 2 lurks in the background.
Linear Mode
