'94 regal computer woes

[TechTranslator]

Just a short preface to explain what's going on here:
My dad is a college- trained mechanic who has never touched a PC,
which is why I'm having to post this in his stead.

Short version: Where is the ECC (I think) computer in a 1994 Buick Regal 4 door Gran Sport? Autozone's website tells us that it's behind the glove compartment, but my father has not found anything resembling a computer there. (not that we actually know what it looks like. We just assume it has a lot of wires running to it.)

Long Version: For two weeks my dad's buick has been sitting dead. His frustration at the situation has led me to post here.
The trouble started with half a gallon of bad gas.
So of course he replaced the fuel filter, then the fuel pump, but even after that his car will die sporadically. Sometimes it will start again immediately, sometimes it will start after a five to ten minute cooldown, and sometimes it refuses to start at all.
After talking to all the mechanics he can think of that might have some clue about the problem, he believes the problem lies in the ECC (?) and has torn the car apart looking for it.
Mainly we need to know the location of the ECC
but I would like to hear other suggestions as to what the problem might be.

Mileage: 266000
Transmission: Automatic with overdrive
Any other information that could be helpful will be provided.
Thank you in advance to anybody who will take the time to assess this problem, because this is his only mode of transportation at this moment.

[ecartman]

The ECM/PCM (engine/power train computer) is located on the passenger side of the engine compartment at the bottom/front of the strut tower. Look for an aluminum box with several connectors and a looms wiring coming out. Many things besides the PCM could be causing your problems, it would be a good idea to have the vehicle scanned before condemning the PCM.

[TechTranslator]

Thank you for such a quick response.
Do you mean this?
http://i397.photobucket.com/albums/p...321111705c.jpg
Dad is looking at me incredulously now for three reasons.
A: it's too easy to get to. People want $1000 to replace it, so he expects to take the car halfway apart to get to the problem.
B: All the "computers" he's been shown at the parts house either had two connections or four. This one has three..
and
C: he was told that this is the airbag control module.

[ecartman]

Yes, that is the PCM/Engine Computer, I've attached a diagram to show your Father. My Father has a '95 regal and it is in the same spot. Anybody who would charge $1000 to replace one of these is just taking you to the cleaners. A reman unit should not cost much more than $200 and one from a salvage yard would be much cheaper (I bought a spare unit for the '95 just in case from a salvage yard for $50) and they don't even have to be programmed like the newer ones just switch out the prom chip from the old one to the replacement and you are good to go. Unfortunately the parts store is showing him the wrong units and whomever said that it is the airbag module is mistaken, that module is under the left side of the instrument panel.

[TechTranslator]

Excellent. again, thank you ever so much for your help.
I only have one question about your statement:
"just switch out the prom chip from the old one to the replacement and you are good to go"
I'm not entirely certain what this is. Will it be obvious when we take out the module?

[ecartman]

No problem. When you remove the old PCM turn it upside down and you will see a rectangular shaped cover held on with a couple of screws. Remove this cover and you will see the prom chip (the chip contains vehicle specific calibrations and must be installed into the replacement PCM since the new one will not come with one). Be careful when removing and installing the chip since they are fairly delicate and easily damaged.

[TechTranslator]

Okay, awesome. Thank you so much. I'll report back on the situation after the change has been made.
Told my dad about the chip and I think we've agreed that I'll do that part.
(^_^ more experience with chips, cards, and computer accessories.)

I didn't mean to ignore the portion about having the car scanned. I believe he's taken that step already, but it's difficult for him to talk so I never get the whole story.

[TechTranslator]

*huff* Well,, the computer replacement went smoothly.

Then he started the car....and two seconds later it died.
Started it again: same result.
And now it won't start at all.


I get the distinct impression that he won't be a Buick owner much longer.


EDIT: May have spoken too soon. Now the car is running like a champ. Haven't yet road-tested it, but it putters around the yard with no trouble. What changed between the last post and now?......dad took a nap.
*shrug*

[TechTranslator]

UPDATE: after two days of driving without any hesitation to start or tendancy to die we're calling this problem resolved!

[ecartman]

Originally Posted by TechTranslator

UPDATE: after two days of driving without any hesitation to start or tendancy to die we're calling this problem resolved!

Thanks for the update, glad you got the problem resolved!

[TechTranslator]

Hello all,
sorry for the bump but there's a new problem with this vehicle and I believe it's related to the recently replaced PCM. Lets see what you think.

The day the PCM was replaced the brake lights and turn indicators stopped working. All the relevant fuses check out, there don't seem to be any shorts that are causing the problem. (dad's disassembles the lights and checked)
Dad doesn't believe the two problems are related because this happened once before, last summer. The brake lights/indicators stopped working for a while but after searching for the problem he got frustrated and slammed the trunk lid....and they began working again. (Of course he's tried the "technical tap" again to no avail.)
Could something have been damaged during the PCM replacement? It was incredibly easy to get to, so I don't see what could have happened. Could the PROM chip need reprogramming?

[brcidd]

Exercise the hazard light switch- turn it on and off 20 times- wiggle it, hold it off to one side-- do turn signals work now?

[TechTranslator]

The hazard light button is missing so I had to do this with a pair of needle-nose pliers.
After 20-30 actions the brake lights began working again, but the turn indicators never did. After another 20-30 actions the brake lights no longer worked.

[brcidd]

Well, at least you have found your problem- see if it repeats, then you can be sure that the multifunction switch is the issue. If so, a new multifunction switch is in order.

[dreager]

7 years and $300 richer

Hi,
As far as the multifunction switch goes it has gone awry 4 times on me over 7 years and i have never had to replace it. The copper contacts inside become fatigued and need to be bent a tad so they are touching better.(This required removal of steering wheel and airbag if it has one by disconnecting battery overnight).
Good luck