Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show


I suspect that I blew the ECM on a 1994 Buick Park Avenue Ultra 3.8 with SuperCharger. I submitted a long history about a year on Car Talk: “Help, I killed my friend’s car” or there abouts. After the initial problem of the engine turning but no ignition (no spark), an OBD would not give any codes. Dead. To shorten the story, I finally found the ECM (I doubt GM couldn’t made it more inaccessible or more difficult to remove if they tried) and removed it. I removed it finally and am in process of finding one to replace it at a salvage yard or getting a remanf. one. One of the located remanf. outfits suggest they can bench test the unit and refurbish it if they don’t have one in stock. Question is can they be bench tested, if so, where and how much. I have been thru every Mitchels, GM shop manuals known going thru the trouble shooter step by step. No the key is black and does not contain a chip other than the antitheft chip on the shaft of the key.

Any Comments

Before you replace the ECU I suggest you check the power to it first and make sure that is ok. The ECU can go bad but they are one of the least items to fail so it is wise to make sure that proper power is getting to the unit. Unless the electrical system has been stressed somehow I would guess the ECU is really ok and it isn’t getting power to it.

There are places you can send the ECU to that can test the units and repair them but you will most likely find a replacement unit at a salvage yard a lot less money than a refurbished unit.

How Do You Think You Blew That ECM And Killed Your Friend’s Car ? That’s Not Easy. What’d You Do ? Tell What Happened And Maybe You Can Get Some Other Suggestions.

Oh, and believe me, GM could have made that ECM even more inaccessable or more difficult to remove, no doubt about it.


Do you happen to know where the PCM is located on a 2001 Buick Century?

Actually, I’ve never had a bad ECM. I used to carry a spare just to rule that out but it was never bad. On the silver box is a code #, you just have to match that code # for the ECM in a junk yard. Then there is a small window with a cover that contains the prom. You need to take the prom out of the old one and put it in the new one. I paid $25 for mine for my old Buick. Don’t know if they can test them or not but don’t see why not, its just a bunch of electronics.

bstf, can’t say for sure without the factory manual, but on my Buick Rivs, they were on the passenger side, above or behind the kick panel, tucked way in there. A silver box maybe 6x8 or 9 inches and maybe 1 1/2 inches thick. A factory manual tells you exactly where and what it looks like. Has two or three large multiple wire connectors to it. I left mine in the car when I junked it so can’t remember precisely.

bstfr. The PCM is located in the air intake box under the hood.

The problem with testing these is that you’d either need an identical car to put it in and drive, or an advanced simulator that can test all the inputs and outputs, such that only the manufacturer is likely to have. If the place you mention tests it, it’s likely they only power it up, perhaps check to see if it generates any codes relating to internal failure, and (doubtful) possibly provide enough basic inputs and outputs to check whether it generates fuel injection pulses and ignition signals.

As far as refurbing, they probably can’t fix a truly dead one, but may be able to replace fried output transistors and other devices related to controlling the engine.