Class 2 Data Bus - Page 2

owenjh · 04-08-2004, 12:53 PM

Actually my Cavalier does not have the Class 2 data bus. I was wrong. As it was a low end, the only thing affected by replacing the stock head unit was the chime when I pull my hand brake (has an idiot light but that still works) and light / key chimes. Personally I couldn't care less about my chimes. and wouldn't spend the $70 on the chimer or $50 on a wiring harness.
If you are looking for a power source for your Aux, just buy a fuse tap, and tap into your wiper fuse, on mine its rated at 20 or 30a. Have never had a problem with this setup, I am not sure if there is even an acc wire on the ignition coil thats why i used the fuse tap.

Hcomplyr · 04-12-2004, 07:02 PM

Sorry to bring this back but will I be able to get one of the newer radios on my 99 monte? i have the 1.5 din unit that has been the standard since 95 or so, and I want the new deck that has the tape deck and CD player combined, but if the radio is VIN activated will i be able to set it for my car?

owenjh · 04-21-2004, 05:33 PM

Not sure what you are asking, do you want to get a new stereo for your monte carlo? or do you want to just want to upgrade the stock one?

CrazyWingman · 05-19-2005, 08:43 AM

Hey - I'm wondering if any of you have a command reference for GM's Delco radios, using their Class 2 bus. I'm planning on hacking a computer together to put in my truck, and I'd really like to hook it up through the head unit's CD Changer port. The pinout for the port lists a Class 2 data line, which I assume is how the head unit would communicate with a CD changer (for next track, text display, etc.). Anyway, anyone know where I could find it? I'm planning on calling the dealer because they were rather helpful in handing over the pinouts, but I thought I'd ask here first.

Thanks!

eugenen · 05-19-2005, 06:37 PM

I would be surprised if the dealer has the commands, they are all preprogrammed into their tech2. Since the class II is standard OBDII it would seem to me you could build a sniffer/capture program and catch all the commands going around the bus. I'd like to try this someday, everything on my truck is controlled by the class II bus, windows, door locks, A/C, etc are all controlled by it.

CrazyWingman · 05-20-2005, 07:07 AM

Yeah, I'd be kind of surprised if they had them too, but in calling around (Delphi first, then GMC, then the dealer), I was told that the dealerships are actually in charge of keeping information around and giving it to users. So, we'll see.

Snooping the bus is my current plan of action, though. I have a module coming in the mail on Monday that will allow me to hook up a laptop and listen over RS232.

I'll be sure to post what I find. (Although I'll probable do it over in this thread).

DavidL · 05-21-2005, 08:42 AM

The Dealerships are not "in charge" of distributing diagnostic information. They provide information as a courtesy for customers. The OEM is legally responsible for providing the service aftermarket certain protocol and transform data (in the US). The dealership will not have PID and transform level data as it is not of any use directly in the repair of vehicles. That low level information has to be translated by software to technician meaningful values used in repair.

eugenen · 05-21-2005, 11:07 AM

The dealship won't know that information, its all in a database in their tech II which just tells them the info they need to know, they won't know what PID is what.
The Basic OBDII stuff is published but there is now law (yet) requiring them to publish the rest, there are many that are trying to get that passed as a law though.

D4Damager · 05-21-2005, 08:09 PM

Hey guys, quick question for ya. Im having a hard time grasping that this system will pose a problem in my truck

I have a 2005 Chev Colorado workers special, which means it has NO options, not even a stock radio. Is my system still affect by this/ can I just install a new cd player and hope it works? I dont have onstar, door chimes or any of this stuff it talks about screwing up

Or do i still need to go through all the BS of getting a harness, etc etc?

eugenen · 05-21-2005, 08:30 PM

The main issue you run into is the oil life monitor reset though there should be an alternate way to do it so I think you should be fine.

D4Damager · 05-21-2005, 10:02 PM

what does it do exactly? and what kind of work around can be done?

eugenen · 05-23-2005, 02:41 PM

There is a way to get to a menu on the radio which reset the change oil message. You can still do it without the radio IIRC its hitting the gas pedal 4 times in 5 seconds with the engine not running.

Starflare5 · 03-11-2007, 11:35 PM

Hello all,

I have been in contact with Delphi on this very issue since I am looking to upgrade the radio in my 2000 Grand Am (not class 2) to one of the newer MP3 playback units (Class 2 capable). In theory it looks as if all I have to do is change the dash bezel and the plug. Delphi neither confirmed nor denied this theory, but they did send me a pinout diagram. It looks like from the diagram that there is not only the class 2 power in, but also the traditional 12 volt batt and 12 volt IGN on the first 2 pins of the top row in the 24 pin connector. Class 2 is on the bottom row pins. These would be the ones next to the AUX 12 pin connector. This points out that these might be a class 2 bypass of some type for non-class 2 vehicles. I'm still getting info, but in that, it would seem that you can upgrade to a newer class 2 capable head unit in a non-class 2 vehicle, but, it's a bit harder to use a non class 2 unit in a class 2 enabled vehicle and you would need and adapter.

Anyway, that is just my theory so far. I'll let you all know how it goes.

Thank you,
Starflare5.

cms88t · 05-14-2007, 09:32 AM

HI guys, just wanted to find out if anyone had more info on putting a class 2 radio into an older vehicle? I know there is a diagnostic mode that lets the unit operate for 10 minutes at a time to do repairs ect. might be able to deactivate the timer so the unit works all the time. You will probably lose the theftlock function though. If anyone has anymore info let me know
thanx

FlatSurfSucks · 06-08-2007, 08:01 PM

Starflare, were you able to get the 12pin AUX pinout? Could you send me whatever they gave you? Or maybe could you tell me who/how you got the info from? I've sent them a message via their website but haven't gotten a reply.