My Bonneville has 207,432 miles. I love it. However, it has started to abruptly shut down. I have taken it to a reliable shop, and they can't find any problems. It happens so randomly. I can't pinpoint a when or where it happens. It'* been two weeks, and it has happened three times. I have been reading the forums and one person suggests the icm pigtail. Another suggests a bus bar connector. Have you had this problem? If so, please share your story and your solution. I really would like to get this problem resolved. Thanks in advanced for your information.

I forgot to mention, the light on the radio stays on, where the dashboard lights go off.

Okay, if this stall problem happens again, if it was "A," what should I do to find this out (ICM)? If it is "B," what should I check for (PMC)? (see if the windows roll down? see if the light stays on? etc.)

Regarding your response, I would like to say all the above hasn't been done, but it has. When it idles in the driveway, it doesn't stall. Actually, it has been with a mechanic for one week--he has been driving it, letting is set for hours while running, etc., etc.,--and not a thing (frustration in my keystroke) has happened. I told the mechanic about your conversation with the other person about the ICM and PCM, and he said, "Yes, it is one of them. However, do you want to roll the dice or do you want me to." He said pick one and we will fix it ($400). If it stalls again, then it was the other problem." He said he can't tell me for sure what the problem is until it dies, and the test equipment registers the problem. Any suggestions? Thanks for your response.

If the speedo did go up and then down, what way to fix would that be? I :? THINK it did. Actually, I'm pretty sure it did.

I'm placing my bets on corodded battery cables. Have him (or you can) clean the battery cables at BOTH ends for BOTH cables.

BTW, where are you located in MI?

Couldnt this be an ignition switch problem as well? The symptoms sound similar. I know they arent a common problem in the Bonneville, but they do go out occasionally. Had one replaced in my SE back in the day.

That would also be something that wouldn't normally show up in testing equipment. Or would it? Im just throwin another idea out there.

A fuel pump relay fixed miine after many, many parts and people looking at it including 2 dealers. I fixed it myself.
rob

As JR said in his first post, do the basics, battery cables, grounds, and also remove the ICM connector and check for clean tight terminals, receptor sockets.
My did the identical stall thing and it turned out to be the ICM connector had a loose socket and when it got hot lost continuity.

Ya, start troubleshooting with the free fixes. Now reason to throw money at it until you've ruled out all the free fixes.