So I was driving to work this morning when my check engine light came on in my 1995 940 sedan. Can someone please help me with how to check the codes? I know you have to ground some kind of connections somewhere(or something like that..), but I am unsure of the location of the computer terminal or which pins to ground or jump. Thanks in advance for the help!

 

you''re looking for a little rectangular black box near the left (driver side) fender hump. the lid of this box lifts off and under it is a pushbutton, LED, and 8(?) numbered holes... there's a jumper wire plugged into a hole on the lid. you take this jumper, and plug it into #2 (fuel injection) or #6 (Ignition Computer), then turn the key on (without starting the motor), and press the button for a few seconds, release it, and count out the rather slow blink codes (should be 3 groups of blinks). after the first code, press the button for another 2-3 seconds, read the next code, repeat this until the first code comes out again. you then press teh button for at least 10 seconds to reset the codes (code 1-1-1 is the default no code). read the codes again to ensure you get 1-1-1 after the reset, sometimes it takes a couple tries.

see Engine and OBD Diagnostic Codes for all the details, and generic meanings of the various codes.

 

Great! Thank you for the help. I'll let you know what I find.

 

When I tried pin 2 it came out 1-1-1. When I tried pin 6 it came out 2-4-1 which(according to the table if I'm reading it correctly) is N/A. Help?

 

go down to the next ICU table, thats the code for EGR flow too low or high.

EGR == exhaust gas recirculation. probable causes: the vacuum lines that control it are leaky, or the EGR pipe that goes around the back of the engine is plugged up at the intake side, or the EGR valve itself is bad.

 

I'll bet my vacuum lines are leaky, I know alot of them are dry rotted. I have a little bit of a rough idle. She bounces between about 600-900 RPM in a "lope" kind of way. I'm planning on changing them soon. Also, when I was checking the codes, I noticed there was another terminal you can plug the jumper into(#3 I think?). What does this one do?

 

i don't remember off the top of my head which one is what, but ABS is in there, so are power memory seats on later models.