How To Build A Phase 2, 4.3 Motronic Flash Code Reader
 

here is your obd port under the coin rack....visual courtesy Chris_Rogers (not that he knows lol)
http://i35.photobucket.com/albums/d1...50_DLC_LED.jpg
connect a wire from the + out feed port, number 16 securing the wire into the port with a paperclip, to a 12volt led......ignore the in line resistor in the picture
connect two wires to the other port of the led....connect one lead to port number 3, again a paper clip will be usefull....
with the ignition off the light should illuminate, although this may not happen on all models...
turn the key to pos II and the light will go out.....

the next step, with key at pos II is to dip your spare wire into port number 5 for a couple (2/3) seconds..., your lamp will illuminate...after a couple of seconds remove the wire from port number 5 and watch the lamp....
it may take a few tries to read the flashes as there will be a pause between each digit for you to record....
for instance the normal, nothing wrong code is
flash.........flash.........flash........
the code for 1-2-3 is
flash.........flash....flash............flash..... flash.....flash.....
it will become obvious when you see it........
to delete any codes insert the port 5 wire for SIX second and remove and wait...after a moment or two the light will flash, immediately and before the light goes out reinsert the wire to port 5 for another 6 seconds..., this may need to be done several times before you get the hang of it.....
by moving the wire from port number 3 to port number 6 and carrying out the same proceedure you can check your climate control ecu
by moving the wire from port number 3 to port number 13 and carrying out the same proceedure you can check your cruise control ecu although you will have to drive the car over 20 mph and not removed the key before you check this, ie to turn off the car turn to position I and then back to II
This proceedure can also be carried out using a 12v multimeter instead of the LED