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

Reply to
George Geno
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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.

Reply to
Daniel J. Stern

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

Reply to
damnnickname

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.

Reply to
maxpower

Reply to
George Geno

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.

Reply to
maxpower

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

Reply to
kmatheson

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

Reply to
maxpower

Both modules meaning PCM and BCM

Reply to
maxpower

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

Reply to
Ted Mittelstaedt

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

Reply to
maxpower

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

"maxpower" wrote in news: snipped-for-privacy@comcast.com:

Reply to
G Geno

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

Ted

Reply to
Ted Mittelstaedt

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