Fault Codes by Paperclip

[safety_match]

I found a good website with easy to follow instructions on how to use a paperclip to generate engine fault codes. Credit goes to http://www.obd1.com/

The Quick Paper Clip Test
Since we are looking at the connector pins, it should be mentioned here that a quick method to see which trouble code or codes are being set in your cars ECM is to jumper the A and B pins of the 12 pin ALDL OBD1 connector with a paper clip. While the car is off, sitting still, turn the ignition key forward while this jumper is in place. Do not start the car. The Service Engine Soon ( SES ) light will flash in a repeating sequence, telling which trouble codes have been set in the ECM. A service manual for your year car will have a chart outlining what each trouble code stands for, or this Trouble Code website can be of help. This paper clip method will tell you the trouble code or codes set in your ECM, but it will not tell you what conditions the trouble code is being set under, or let you clear the trouble codes on the fly, as the ALDL cable and PC setup will.

 

[Agent 86]

If thats all it tells it seem to be lacking. It doesn't mention that the it will flash 12 three times followed by the code three times followed by 12 three times. Maybe it tells more in the links but they were too slow too load so i dumped it.
Is it raining there

 

[Agent 86]

For those who want to save it, here is the GM version
http://members.shaw.ca/corvette86/Non%20Scan%20Diagnostic%20Circuit%20Check.pdf

 

[safety_match]

Thanks for a more in-depth report. But for those of us who are not so mechanically inclined the first one give a quick and easy overview. After reading the first one, yours makes more sense.

thanks, Safety

 

[MBDiagMan]

I've used the paperclip method for years. I found a VERY good description in the Haynes manual.

Some Haynes manuals on certain cars are very good and others aren't so good. The Haynes manual on the C4 is excellent and worth the $15 or so.

Good luck,

 

[85vette]

thanks to all for sharing
i like the trouble code website reference

 

[85vette]

by the way, if it isn't clear in the instructions a 12 code will be 1 long flash followed by 2 short flashes etc.