1995 Chrysler Cirrus PCM removed/replaced -- car honks like crazy.What's up?

Last summer I made an effort to replace the PCM on my Chrysler Cirrus.
I sent my PCM to a shop that presumably would repair it. They turned
out to be a sham and I thought I'd lost my PCM. So I did my best to
determine the proper part number and started hunting in parts yards. I
came up with what I thought was the same unit -- it had identical
connectors, came from a 95 Cirrus like mine and so on.

I installed it and things were great. The car's AC worked again (hadn't
worked in a year), the car didn't die at a stop, and idled great. I
wrapped it up and went inside. Shortly afterwards (maybe 15 mins) my
wife ran in to say the car was honking and wouldn't stop.

I had to remove battery connections to get it to stop. Odd thing on
this was, I didn't think I had a car alarm.

I managed to find the jerk who had snatched my computer and his stash
and got it all back. I found out that I had a PCM with a part number
that differed in one digit.

I placed the old but semi-functional PCM back into the car and
reconnected the battery to hear the sound of honking.

What have I done? Have I managed to cook something else? the BCM
perhaps? Or is there something that I need to reset?

Any advice and pointers to repair/replace resources for the still bad
PCM would be very appreciated.

Regards,
G Geno

 

The one problem could have nothing to do with t'other. You might just
happen to have a bad horn relay, horn switch or clockspring.

 

Thats the reason you do not swap out Modules on todays vehicles, you just
told the BCm that the vehicle has an alarm when it doesnt.
Replacement of the BCM to correct the problem.

Glenn Beasley
Chrysler Tech

 

The VTSS function on LH and JA vehicles resides in the PCM and BCM. Either
module becomes programmed to support VTSS when they are installed in a VTSS
enabled vehicle. The modules will carry this information with them if they
are transported from one vehicle to another, and will "teach" the new
vehicle that it has VTSS. This "teaching" will occur as soon as the ignition
is turned on. Installing a VTSS enabled module in a non-VTSS equipped
vehicle will cause a no-start condition or improper theft alarm actuation.

 

Is there no way to "reinform" the BCM that there is no alarm?

 

The VTSS function on LH and JA vehicles resides in the PCM and BCM. Either
module becomes programmed to support VTSS when they are installed in a VTSS
enabled vehicle. The modules will carry this information with them if they
are transported from one vehicle to another, and will "teach" the new
vehicle that it has VTSS. This "teaching" will occur as soon as the ignition
is turned on. Installing a VTSS enabled module in a non-VTSS equipped
vehicle will cause a no-start condition or improper theft alarm actuation.

 

If you replace it with one having the same part number will it work, or
must a new one be purchased from the dealer?

-Kirk Matheson

 

I don't know, I don't use used auto parts, whats to say someone didn't
already swap them out and cause that problem with the used one? either way,
if the OP has done that, he will need to replace both modules at the same
time

Glenn Beasley
Chrysler Tech

 

Both modules meaning PCM and BCM

 

Generally wreckers do not take back auto parts. Once it's out it's never
coming back in.

I do use used auto parts but there is a right way and a wrong way to use
used auto parts. For starters, you don't buy anything from a wrecking
yard that is a wearable item. For example we have yards here that give
away "free" antifreeze. Well of course, it's a haz-mat for them that they
have
to pay to dispose of. You would have to be a total idiot to put that in
your car. I've been in a number of U-pull-it yards and I've seen people
buy brake pads, batteries, and other consumables.

For seconds, you have to be very leery of anything that isn't exactly
visible.
For example, alternators and starters - these have parts inside (brushes)
that you don't know the condition of, they are a big risk. Or sensors,
coils,
or rack & pinion. Fuel pumps are another one. Most likely your
money's going down the rathole. I have taken such a risk before, and
it came out OK - I put a wrecking yard complete engine and a wrecking
yard complete transmission in my Datsun 210, but this was a non-computer
controlled vehicle that was worthless, I had little money and nothing
to lose at the time.

Obviously, the best used parts are hard parts, ie: body parts, brackets,
etc. Or cores, such as a complete engine that your going to send off
to the rebuilder.

Computers and such I would only take after -throughly- researching them.
The anti-theft problem with the PCM/BCM has already been documented
on this newsgroup in the past, and the OP should have reviewed Google
Groups archives before experimenting.

Ted

 

Even these parts are going to start to have problems when they start
funneling out of Mississippi and New Orleans flood zones

Glenn Beasley
Chrysler Tech

 

OK....I've finally gotten around to pursuing a new BCM and PCM for my 95
Cirrus. I went to the library to check the Chilton's on how to get to
the BCM. In the book I discover that every JA-body machine (includes
Cirrus) has the VTSS and "every" time a PCM is replaced the VTSS needs
to be "reverified" and that includes cranking the engine 20 times after
starting with driver door open, all others closed, etc., etc.

So I have a bit of a procedure here from Chilton's that sounds like it
may reset the VTSS and then I'm back to only needing the PCM. I'm going
to give this a try before I go under the dash to get the BCM out, but it
sounds to me like even a dealer shop would have the situation with the
alarm sounding when a new PCM is installed whether or not there is a new
BCM going in.

Make sense?

-G Geno

 

Try it and tell us. I think, though, your first problem is relying on
Chiltons.

Ted