Interfacing BCM control of lights/locks + aftermarket remote start/keyless entry

Background: I'm installing a Commando EZ-2500 remote start/keyless
entry system in my 97 Pontiac Trans Sport Montana (which has OEM keyless entry
& no factory alarm/content theft). The remote start portion is fairly
straightforward, but I'm curious about the keyless entry part. This
van has a 3-wire negative (-) lock system, so actually "requesting" a
lock or unlock is easy; there are lock and unlock (-) pulse outputs
directly from the Commando unit.

However, I'm trying to determine what pulse is sent to which wire (at
the BCM) when I press either lock or unlock on my GM keyfob. I want
to retain all of the functions and programmability that the BCM does
to the lights and locks, such as: domelight on for 60 secs when
unlocking w/ keyfob, domelight off when locking with keyfob, delayed
locking (last door closed), driver's door priority, and a million
other little "features" that I think are pretty useful.

Now, before you say, "why don't you just turn on your domelights with
the built-in domelight output on your aftermarket system and be done
with it?" - Well, I don't really want to use it. Why? Lots of
reasons. It doesn't turn the lights off when you "lock", or control
any of the "advanced" stuff I mentioned earlier. Trivial, maybe, I
know. In any case, I'm not really expecting an aftermarket alarm to
do (on its own) all of the things that the BCM does - which is brings
me to my question...

When I use my OEM keyfob, where specifically does the "unlock" or
"lock" pulse get sent so that the BCM can, in turn, turn domelights
on/off, check if doors are open, delay locking, all those wonderful
"gadgets" that I mentioned earlier, etc? I would think it is just the
same (-) pulse on the lock/unlock wire.

To clarify, I'm not trying to reverse-engineer my BCM, as its not a
cheap device to be screwing with. I just want to know how it gets
that darn signal from the keyfob that a lock or unlock has been
requested so I can make the Commando send the same signal to it
(whether it requires a relay to reverse polarity or whatever). I just
want to retain the OEM functionality of all the entry/exit features.
Ahh!

Perhaps I am thinking too hard, and the BCM will, in fact, "see" the
same lock or unlock pulse that it does w/ the GM keyfob when I
connect the (-) lock/unlock output wires from the Commando to the lt
blue & white (-) lock/unlock wires in my vehicle.

Anyone ever deal with a similar install? I would appreciate feedback.

Thanks!
Bryan

"NoTomatoesPlease" <iaskedfornotomatoes@yahoo.com> wrote in message
news:18774da6.0403091422.1cc1cb82@posting.google.c om...
> Background: I'm installing a Commando EZ-2500 remote start/keyless
> entry system in my 97 Pontiac Trans Sport Montana (which has OEM keyless
entry
> & no factory alarm/content theft). The remote start portion is fairly
> straightforward, but I'm curious about the keyless entry part. This
> van has a 3-wire negative (-) lock system, so actually "requesting" a
> lock or unlock is easy; there are lock and unlock (-) pulse outputs
> directly from the Commando unit.
>
> However, I'm trying to determine what pulse is sent to which wire (at
> the BCM) when I press either lock or unlock on my GM keyfob. I want
> to retain all of the functions and programmability that the BCM does
> to the lights and locks, such as: domelight on for 60 secs when
> unlocking w/ keyfob, domelight off when locking with keyfob, delayed
> locking (last door closed), driver's door priority, and a million
> other little "features" that I think are pretty useful.
>
> Now, before you say, "why don't you just turn on your domelights with
> the built-in domelight output on your aftermarket system and be done
> with it?" - Well, I don't really want to use it. Why? Lots of
> reasons. It doesn't turn the lights off when you "lock", or control
> any of the "advanced" stuff I mentioned earlier. Trivial, maybe, I
> know. In any case, I'm not really expecting an aftermarket alarm to
> do (on its own) all of the things that the BCM does - which is brings
> me to my question...
>
> When I use my OEM keyfob, where specifically does the "unlock" or
> "lock" pulse get sent so that the BCM can, in turn, turn domelights
> on/off, check if doors are open, delay locking, all those wonderful
> "gadgets" that I mentioned earlier, etc? I would think it is just the
> same (-) pulse on the lock/unlock wire.
>
> To clarify, I'm not trying to reverse-engineer my BCM, as its not a
> cheap device to be screwing with. I just want to know how it gets
> that darn signal from the keyfob that a lock or unlock has been
> requested so I can make the Commando send the same signal to it
> (whether it requires a relay to reverse polarity or whatever). I just
> want to retain the OEM functionality of all the entry/exit features.
> Ahh!
>
> Perhaps I am thinking too hard, and the BCM will, in fact, "see" the
> same lock or unlock pulse that it does w/ the GM keyfob when I
> connect the (-) lock/unlock output wires from the Commando to the lt
> blue & white (-) lock/unlock wires in my vehicle.
>
> Anyone ever deal with a similar install? I would appreciate feedback.
>
> Thanks!
> Bryan

From the looks of the BC Circuit schematic in front of me it looks like it
gets a signal and from that it sends another signal to everything under the
sun :P If you want a copy I can post it somewhere. But there something
called the "RFI CNDI (REMOTE DR LCK RCVR)" and I think that's what you're
looking for and thats a Black\White wire at C8.

Thanks for the reply; would you mind posting that somewhere (if it's
not too much trouble)? Or you can email it to me if that's easier.

Bryan

> "Phillip Schmid" <schmste8@hotmail.com> wrote in message
> news:<c2m97m$1v4det$1@ID-72906.news.uni-berlin.de>...
>
> From the looks of the BC Circuit schematic in front of me it looks like it
> gets a signal and from that it sends another signal to everything under the
> sun :P If you want a copy I can post it somewhere. But there something
> called the "RFI CNDI (REMOTE DR LCK RCVR)" and I think that's what you're
> looking for and thats a Black\White wire at C8.

www.bought4less.com
you would use your OE remotes, and retain all your OE features you so enjoy
and also have remote start.
SCS RS5000

"NoTomatoesPlease" <iaskedfornotomatoes@yahoo.com> wrote in message
news:18774da6.0403091422.1cc1cb82@posting.google.c om...
> Background: I'm installing a Commando EZ-2500 remote start/keyless
> entry system in my 97 Pontiac Trans Sport Montana (which has OEM keyless
entry
> & no factory alarm/content theft). The remote start portion is fairly
> straightforward, but I'm curious about the keyless entry part. This
> van has a 3-wire negative (-) lock system, so actually "requesting" a
> lock or unlock is easy; there are lock and unlock (-) pulse outputs
> directly from the Commando unit.
>
> However, I'm trying to determine what pulse is sent to which wire (at
> the BCM) when I press either lock or unlock on my GM keyfob. I want
> to retain all of the functions and programmability that the BCM does
> to the lights and locks, such as: domelight on for 60 secs when
> unlocking w/ keyfob, domelight off when locking with keyfob, delayed
> locking (last door closed), driver's door priority, and a million
> other little "features" that I think are pretty useful.
>
> Now, before you say, "why don't you just turn on your domelights with
> the built-in domelight output on your aftermarket system and be done
> with it?" - Well, I don't really want to use it. Why? Lots of
> reasons. It doesn't turn the lights off when you "lock", or control
> any of the "advanced" stuff I mentioned earlier. Trivial, maybe, I
> know. In any case, I'm not really expecting an aftermarket alarm to
> do (on its own) all of the things that the BCM does - which is brings
> me to my question...
>
> When I use my OEM keyfob, where specifically does the "unlock" or
> "lock" pulse get sent so that the BCM can, in turn, turn domelights
> on/off, check if doors are open, delay locking, all those wonderful
> "gadgets" that I mentioned earlier, etc? I would think it is just the
> same (-) pulse on the lock/unlock wire.
>
> To clarify, I'm not trying to reverse-engineer my BCM, as its not a
> cheap device to be screwing with. I just want to know how it gets
> that darn signal from the keyfob that a lock or unlock has been
> requested so I can make the Commando send the same signal to it
> (whether it requires a relay to reverse polarity or whatever). I just
> want to retain the OEM functionality of all the entry/exit features.
> Ahh!
>
> Perhaps I am thinking too hard, and the BCM will, in fact, "see" the
> same lock or unlock pulse that it does w/ the GM keyfob when I
> connect the (-) lock/unlock output wires from the Commando to the lt
> blue & white (-) lock/unlock wires in my vehicle.
>
> Anyone ever deal with a similar install? I would appreciate feedback.
>
> Thanks!
> Bryan

"NoTomatoesPlease" <iaskedfornotomatoes@yahoo.com> wrote in message
news:18774da6.0403100613.7b917340@posting.google.c om...
> Thanks for the reply; would you mind posting that somewhere (if it's
> not too much trouble)? Or you can email it to me if that's easier.
>
> Bryan
>

No problem. http://home.wi.rr.com/schmste8/images/BCM97PT.JPG

"Phillip Schmid" <schmste8@hotmail.com> wrote in message news:<c2o6r4$1uc30i$1@ID-72906.news.uni-berlin.de>...
> "NoTomatoesPlease" <iaskedfornotomatoes@yahoo.com> wrote in message
> news:18774da6.0403100613.7b917340@posting.google.c om...
> > Thanks for the reply; would you mind posting that somewhere (if it's
> > not too much trouble)? Or you can email it to me if that's easier.
> >
> > Bryan
> >
>
> No problem. http://home.wi.rr.com/schmste8/images/BCM97PT.JPG

That's EXACTLY what I was looking for! If it's not too much trouble,
I'd also be curious as to the location of the keyless entry receiver
that is on the other end of pin C8. Do you have a diagram by chance
of the pinouts for that one as well?

My next step will be determining what exactly is happening on that
wire when I press Lock or Unlock on the factory remote - time to break
out the multitester this weekend...

Thanks again,
Bryan

Oh, no...I'm not trying to duplicate the RF signal that the OEM
remotes send. Rather, I want to mimick the OEM keyless receiver's
OUTPUT (not the RF input) to the BCM. The concept is really, really
simple.

In fact, It's pretty much the same exact method that any remote start
module uses in sending a signal on its starter output to "fool" the
car into thinking the driver turned the key to start at the ign
switch. You're just duplicating an existing function by tapping into
a wire plugged into a factory harness somewhere. The difference in my
case, as Phillip's pinout diagram for the BCM shows, is that it
appears there is only one wire coming from the OEM keyless receiver,
which says to me that the way the OEM keyless receiver sends off a
"lock" or "unlock" signal to pin C8 @ the BCM is by differing voltages
or resistances on the wire and in turn...which means I'll be spending
some quality time under the dash with a multimeter this weekend
probably. :P

If it turns out that it is, in fact just differing voltage/resistance
on the wire, I'll put together a mess of diodes and/or resistors from
Radio Shack and cross my fingers (hence the box of "???"s in my
diagram below).

The layout would look something along these lines (minus lots of wires
that aren't important, for the sake of simplicity): *fun ASCII art
ahead*

i =input, o =output, -> =current flow

* ----------------
| |remt start & o|-starter->
| |keyless module o|-accessorywire->
|-|i o|-parklights-> -------
| o|-lockpress-----| ? ? ? |
| o|-unlockpress---| who |
---------------- | knows |
| ? ? ? |
* -------
| |
| ------------- | -------------
|-|i o|->-OEMkeyfobsignal-----*->|i(pin C8) o|--chime->
|OEM keyless | | BCM o|-domelamp->
|remote | | o|--horn->
|receiver | | o|-etc->
------------- -------------


> "I'm Right" <ImRight@urWrong.net> wrote in message news:<1wG3c.27772
> $8j5.2953@newssvr24.news.prodigy.com>...
> www.bought4less.com
> you would use your OE remotes, and retain all your OE features you so enjoy
> and also have remote start.
> SCS RS5000