can someone tell me what letter I have to use a jumper wire to start the code reading?
a to c c to b ect... need asap

 

There is NO jumper wire... Your car should have a little probe attached to the Code Box and you stick this probe into socket #2 to read the codes. You press the button for a short 1 second and wait for the flashing lights. You count the flashes and these are the codes.

 

I moved this to a new thread, as it has nothing to do with the 2005 thread it was appended to.

Hodester, noone here is going to remember what car you have, or want to spend the trouble to search for your other posts and try to puzzle it out. you need to supply a little more information.... or at least stick with the thread where you've already given that information. WHen you start a new thread, its EXTREMELY helpful to supply the year and model car in the TOPIC so we don't have to search around to find out this critical information.

as stated, your question doesn't even make sense? letters? jumper wires?

1989+ 240/740/940 nonturbo, and 1990+ 7/9 turbos, have "OBD-1" diagnostics. see Engine and OBD Diagnostic Codes for the procedures to read them, and how to interpret the codes.

older 240/740/940 had no diagnostics at all.

1996+ cars in the USA have OBD-II which requires a plug-in code reader, but they stopped selling 240/940 here before then.

 

OR ,,, use the "signature" option in your "User CP" to add info about your car so you don't have to remember to post it when you go to post questions.

At least the basics like year, model, turbo or NA, manual or auto