Just a reminder to save you a WHOLE lot of time if you are having lots of problems and can't find a root for the problem. Try swapping your ECM!!

Spent 5 days (about 4-5 hours a day) working on a friends Cutlass Supreme... went through everything... tried replacing all kinds of stuff and pulling lots of codes everywhere.... it turns out the computer was bad and the codes that were being sent had NOTHING to do with what was wrong with the car.... It's a darn good thing that I have a hook up at a local auto parts store and was able to "borrow" sensors to try out.

So.. again... if you're stuck with things you can't figure out.. try replacing the ECM :yesnod: :yesnod: :yesnod:


[Modified by Glock'94, 5:16 PM 1/22/2002]

 

Agree, and add these two comments together:

If you are going to work on a fuel injected engine you need two things:

To learn how each sensor works, and how it effects the system.

A scanner.

No question.

 

:yesnod: :yesnod:

 

I would agree with PeteL a scan tool can be very helpfull, but also knowing what you are looking at. A scan tool would do very little for you if you did not know what was normal, I would recomend anyone with a scan tool to hook one up(to a good running car) and see what it should be. Expearance is also something else that is very usefull. I used to do just about all my diagnostics with an A-B key, find the code or codes and beable to tell just what was needed, but you have to remember that not all codes are point you to a faulty sensor, PeteL just wenh through a case were he had a code 15 but there was nothing wrong with the sensor it was the computer that was sending out the wrong voltage( I don't know if he checked the voltage at the coolant sensor but I bet it was about 12 volts instead of 5 volts) but he was able to use a scan tool and see that the voltages he was reading were way out so he knew it was the computer, but the other usefull tool would be a DVOM(digital volt ohm meter). But on the other hand don't be to quick to replace the ECM( unless you have a 1227165) you need to first find out if the computer is seeing the incorrect readings or thinks it is.


David Fulcher

 

Oh, I have scanning stuff for my car, but my friend's '89 cutlass supreme.. I couldn't find ANY software to get any readings off of it :crazy:

 

I forgot the most important:

#3: Listen to every post that David-F makes.

Actually never looked at voltage on CTS, because the scanner readings were so screwed up I knew I was in trouble. Funny, I was thinking that I hope it's not the ecm, but really that was a cheap and quick solution. That is part of the home troubleshooting mindset that I have - "hope it's not the ecm." Well it was, it cost $120 and a few days later the car is running great. So that is much better than guessing at a million parts (and replaceing them), and not getting your car back.

Back to #3: Lots of the newer folk here have no idea, David knows how these cars work.

Thanks David