TAXMJF3

what is this i hear about being able to use a paperclip to read codes off the ECU??? If this is true how do i do it? Thanks, Aaron

TekViper

https://www.thirdgen.org/newdesign/faq/thirdgen.shtml

scroll down to miscelanious. however i have seen 2 different articles saying 2 completely different sets of pins to do this. i havent done it on my 90 3.1L firebird yet cuz im not sure which 2 pins i have to short, as i see it written 2 different ways written. if anyone knows let me know. does it make a difference if the ALDL is on the right or left side of the steering wheel? mines on the left but i see a lot with them on the right.

zoomzoom

If you look at your ALDL connector closely you'll see that it's marked. Just short terminals A & B. Do not mess "M" it's the data stream for the code reader.
The test is done with the ignition turned On and the engine not running. A Code 12 will flash on the Check Engine light 3 times and then give you any additional codes if present.

Quick_Trans_Am

iTrader: (2)

zoom zoom is right. I've done the same thing many times on my 3.1L. Any metal paperclip or even a piece of wire will work fine.

NHRATA01

The paper clip thing works, but I just went to Sears and bought a GM code scanner along with a book explaining what the codes indicate for 25 bucks. A lot less of a PITA for only a little bit of money.

TekViper

why is the tech article on this site saying to short A and M according to that picture? oh nm, it says 5 to 6 on later cars, i guess 1990 was the change over year?

TomP

Not sure. I also short A to B, and my '86 has the slower computer.

You guys ever see the Dodge/Plymouth method for this? You turn the ignition key back and forth about a hundred times to start diagnostic mode. The Ford method is even worse, you gotta hook up a multimeter!

TekViper

i did it yesterday on the 90 bird. its A to B. no codes!

zoomzoom

Make sure your SES light bulb is not buned out.

Nixon1

Tom..not necessarily about the Fords..my Ford has the same kind of connector that's in ours, but it's under the hood. I don't have to use a multimeter or anything...just haven't gotten around to actually try to use the thing. Actually the Ford computer system is, in my opinion, more capable....the thing can actually do a test where it fires all of the injectors and tests something, I forget what it tests...but it can actually give you an early warning if you have a compression issue on any of your cylinders. Very cool...

TekViper

light blinks code 12 over and over zoomzoom.

zoomzoom

Ok, start at the beggining I'll post the Helms charts, use this one first then move to the next two. Hope this helps you some.

zoomzoom

Here is A-1

zoomzoom

Ok, I guess I can't delete my own posts?? I'll repost then.

zoomzoom

Ok, lets try this again, HERE is A-1

zoomzoom

This is the circuit description for A-1

zoomzoom

And this is the flow chart for A-1

zoomzoom

I guess I should have asked you if you were having any problems with your car. If you are not and there are no stored codes on the ECM, when you short A & B you will get a code 12 & nothing else.

TekViper

no major problems as far as i can tell.

zoomzoom

Ok, then to make sure we are on the same page look at "Chart 1" and fallow along.

1- At this point DO NOT jump the ALDL terminals do not mess with them at all!!!

2- Do like the chart says: Turn ignition to "ON" position (DO NOT START ENGINE)

3- Look at your SES light. You are only going to have one of three results here.

A- Your SES light will come on and stay on.

B- No SES light at all.

C- Your SES light will flash a code 12 (again, make sure you are not jumping terminals A & B at the ALDL at this point!)

To keep this simple, do the above test & let me know the results will take it to the next step at that point.

TekViper

my ses light just stays on. what are we trying to establish here? i have no questions about the ses light i was just confused on why some computers u short 2 different pins. now i know.

zoomzoom

Dude, reading your post it sounded like you were getting a code 12 without shorting the ALDL test terminals............Neeeever Miiind!!!

TekViper

haha sorry