Hey there peeps,
I went out to the garage and fired up the ol' Bonneville. It'* a 1989 LE. Everything was fine until the beloved Service Engine Soon light came on. I took it to autozone, they tested it and said the error was a Code 42. I know it has something to do with the EST. Does anyone have any advice? What exact sensor it is? and How to replace it?? I would be most grateful for any help...... :?:
Take Care, Bryan

First thing, read this article. It is in the TechInfo [located at the top of this screen, or any screen for that matter]. Code 42 is something to do with the Electronic Spark Control Circuit.. what that means? I honestly don't know. I'll let someone who knows chime in on that one.

Another note, you can retrieve your own codes with a paperclip. That article [the link above] has the procedure.


-justin

Electronic Spark Control Circuit is an interaction between the Ignition Module and the ECM. I'd check out the Ignition Module first.

Thanks for the replies....I still have no idea what to do.....When checked at autozone..said it could be 3 possible parts, all sensors to my knowledge. I just know they are 4, 8, and 27 bucks. Hmm..now which one should I replace?? hahhahah If anyone else has had this Code 42, please enlighten me as to how you fixed it. I'll bet its the real cheap part and easy to do myself....yet it looks like I will have to shell out some bucks for a mechanic... :(

I don't have a clue as to where the ignition module and/or ECM is either. This is a little more than the basics for me.... I'm not sure if this is related, but the car starts right up....There is most definately an acceleration and idle issue though...

Talked to two dealer service centers.....they won't mess with anything older than 1993..

Wow, I thought I was the only one out there who loved my "hoopty" bonneville. You guys and I'm sure there are some ladies as well, that really like Bonne'*. Mine is faded silver, has its share of dings....was hit by a drunk driver a year ago..minimal damage..still appealing his insurance company...yup..i'm gonna sue the convicted drunk if its denied again and get a super nice paint job....What others have said to be junk is my little treasure...She did me well in college for years and I can't give it up! The car that is... Hey it only has 100,000 miles on it and floats on the road. (old lady had it before me and serviced the hell out of it) Big change from my year old grand prix though. Had I known about this forum sooner.....I'd have bought the new Bonneville...There'* some real love for em out there.....

Some of these posts really crack me up...
again..if anyone knows anything about fixing that code 42. let me know.....
Peace

Ignition module is located under your coil packs, connected to a wire harness. If you go to the wrecker you can use the ICM out of ANY 3800 engine. I would also recommend upgrading your coil packs to the Delco version while your at it.

Okay, We'll start from the beginning, Assuming you know very little.

The spark plug wires hook to the spark plugs, You can find those right? On the other end of the spark plug wires are the Ignition Coil Packs. Three little black boxes, each held down with two 7mm bolts. Directly under them is a slab of black plastic, mounted to a peice of aluminum with three 10mm nuts. That'* the ICM, Ignition Control Module.

On the passenger side of the dash, up underneath is a big peice of black plastic covering everything. If you remove that and look up inside the dash, there'* a shiny silver box in there with about 100 wires hooked to it. that'* the ECM, Engine Control Module. It'* held in by the single 10mm nut that you can see. If you're going to replace that, once you get it out of the car you'll notice a cover held on by two screws. Underneath that is a big computer chip. Remember that the chip stays with the car.

Dame, Thanks for the information. I'm learning a lot about this ol' car of mine.. I assume those areas you speak of have something to do with the Electronic Spark Timing, or EST. Again, Autozones inventory computer says when you get this Code 42 it can one or more of 3 sensors. I remember one of them being something about a crankshaft sensor??? Sound right to anyone? All of the sensors related were relatively cheap. I wouldn't mind replacing all 3 simply for the age of the car.....Just not sure how to do it....or where they are located. Still wondering if anyone has had similar problems or had to replace the sensors related to this code...

As far as replacing the ICM (and coil packs) this thread will tell you everything about the upgrade. I had no idea how to do anything and the people here explained it all. I am not sure about the crank sensor though, but if you search around I'm sure you will pull up some valuable threads.

Cap.....not sure if all that needs to be replaced.....or do I? Was my understanding f'n code 42 is just sensor related....Thanks for being patient LOL it'* a learning process.....