Problems with the E and C Data Bus

[Starflare5]

Hi all,

Now, I've seen countless notes and info here for the GM Class 2 Data Bus Configuration, however, I have a 2000 Grand AM with the yee old Entertainment & Comfort Data Bus configuration with a new twist. It turns out that, like with the class 2 config, these vehicles have the chime running from the BCM through the E&C to the radio as well.... My vehicle has never chimed even when I bought it used and it has a factory radio. After alot of research and digging, I discovered (first found that the remote keyless mod had been removed properly). I found that there is no, zip, zilch, zero, nada E&C signal running to my radio, even though the wire is there. I went to a dealer and their best suggestion thus far was to wire or splice the E&C wire directly to the line comming out of the BCM. If this still does not work, then the E&C may have been shorted out by the previous owner, which would result in replacement of the BCM. I doubt that it is shorted out because all other functions work fine, however, I still need to test this which brings me to my question.

Does anyone here know exactly which green wire on the BCM is the E&C data bus out for the 2000 Grand Am, or, does anyone have a wiring diagram of the BCM?

Please let me know so I can find out how serious this problem really is.

Thank you,
Starflare5.

[rixGAphx]

Originally posted by Starflare5
Please let me know so I can find out how serious this problem really is. In comparison to other GA problems, especially electrical, on a scale of 1-to-10 this 'problem' (something doesn't chime) rates about a 0.5 IMO.

Clean your battery cables and give thanks to the detroit gods that your car is otherwise excellent.

[Starflare5]

Hello there,

All joking aside, there is a more pertinent reason why I asked for help on this issue. The E & C Data bus itself. If there is a failure in it and it is dead, it could lead to other problems down the road. I have heard of the BCMs in these vehicles dying and I want to catch it before I end-up stuck on the side of the road with my ABS, Brake and other lights on and the vehicle no longer functioning. This is also a concern brought up by my GM dealer's service department. Remember, these vehicles use the data bus to communicate with other modules in the car. Also, the E & C in the 1999-2000 GA is actually a precurser to the actual Class 2 and GMLAN in newer vehicles and not just the old Entertainment and Comfort anymore.

With all that said, my dealer service center mentioned that the best way to test this is to tap directly into e & C coming out of the BCM. If there is a signal or chime, then it's not dead. If there is no signal or chime, then I have to replace the BCM before it kills over which this is one of the signs that it's heading in that direction.

So, again, which green wire is it?

Thank you,
Starflare5.

[rixGAphx]

I'm working on a new design for Phoenix-area pedestrian shelters to go along the sidewalks.
For the municipal busses that drive on the street. :roll:
Other busses confuse me.

You may have to wait a while for somebody who knows a **** about data busses and such to come along here.

Matt'95 is pretty knowledgeable IIRC.

[Starflare5]

Hello all,

Ok, I feel a little stupid panicing like I did, but, also, a little more baffled. I found out due to another person here, and Delphi, that the E&C is not really a precurser to class 2, but, more of an overlay because all '99 and up GAs have class 2. Just not linked to the radio until 2001. The E&C is in place as a secondary bus for older electronics.

I found out that there is a wierder problem why I have no chimes, and will not beable to solve it until I get an RKE.

On most '99 and newer GAs, the chimes were stored in the RKE or the BCM, depending on the option package, and in some cases, both. The reason the E&C to the radio seems dead in my car is because first of all, the RKE was removed from my vehicle and replaced with factory jumpers. The jumpers themselves might be the wrong ones, and, therfore, have no link to the radio E&C.

I'm thinking that it also might be easier if I just get a class 2 radio and run a wire from the BCM's class 2 to it. It would sure help if someone here could send me a BCM diagram. If there's anyonethat can help, please send.

Thank you,
Starflare5.