Close, but the body computer was not the issue. Nothing that has to do with the EVIC system will work without the "premium" body control module. The issue was that he was using 1992+ electronics in a 1991 car. He has some contacts with engineers or whatnot who work for the "big 3" automakers and that is where he discovered that there was a change in the data bus communication for the 1992 model year. He took the SBEC out of his IROC R/T and jiry rigged it to the 8 valve engine in his '91 Shelby, raised the front of the car and spun a wheel by hand and suddenly the digital speedometer came to life and would actually get a reading. The suppliers of SBECs changed for the 1992 model year.Originally Posted by Reaper1
I did a little extra memory refreshment, and read some old emails that reminded me of a few things:
It always helps to get the wiring from the same car you got all of the
above. There are a lot of extra wires feeding into the new body computer
that read switches like "trunk ajar" or "washer fluid low", or "driver's
door ajar" and "passenger door ajar". To get those last two to work properly
you will need to wire the diode pack (in the relay box above the driver's
kick panel) in a different fashion than what the non-EVIC cars had.
Good luck doing that without pulling the dash.
Oh, and I almost forgot, you will also need to get the lamp outage module.
This is a small black/gray box above the glove compartment that hooks into
the headlamp and tail lamp wiring and has 3 wires feeding to the body
computer. These wires are triggers for "headlamp out", "tail lamp out", and
"stop lamp out" (I think, or is it "turn signal out"). There are 2 versions
of this box, the one for single rear stop lamp and one box for dual rear
stop lamp (like the GTC). I have a single rear stop lamp box, but the
Daytonas have dual rear lamps, so I couldn't hook mine up. The New Yorkers
have this same box, but again, in '91 or '92 they changed the wiring a bit.
The later ones have two fuses, one for each headlamp and the older ones have
one fuse for both headlamps. The single fuse has one wire going to the lamp
outage box where it splits into two, one to go to each headlamp (one in, two
out). The later ones have each headlamp fuse sending a discrete wire to the
lamp outage box, where the pair pass through side by side (two in, two out).
This just goes to add to the complexity of implementing the EVIC system to be FULLY functional.
Now here is where it gets a bit confusing. You can take a 1990 2-button traveler thing and stuff it into a 1995 car and it'll plug right in and work. This would suggest compatibility over all the years with the CCD bus. You can also take a 2-button unit out of a 1988 new yorker, plug it into a 1995 J-body, and it works.The CCD bus will interact with almost all of the electronics that have anything to do with running the engine, monitoring the engine, or taking care of body functions/monitoring. If the bus changed, so did all of the electronics that interact with it.
BUT, when it comes to the EVIC stuff, it doesn't happen from 1988 through 1995. It is as though the bus has two (or more?) different types of data packets running on it. Some stuff that utilizes certain information on the data bus will work (such as the LCD display dimming of modules) is compatible all around, but there are data packets with information such as, "HEY, your door is ajar!" that are not recognized by all devices, and with a change to those items' communication in 1992.
Kinda like IPX/SPX data packets and TCP/IP V4 data packets running over an ethernet network simultaneously. If the network nodes quit handling IPV4 packets and started handling IPV6 packets, all the IPV4 hardware won't work. But the IPX/SPX stuff will still function fine... I believe that it is that type of thing.
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? So whats the story with Jackson's pet Pigeon
