I understand that you can get the trouble codes with a simple 12v tester ( the kind with a light bulb and wire). Apparantly there is a way to connect the tester to the diagnostic port next to the battery and ground various pins to read the different systems (ABS, SRS, ECU). Each system will pulse 12v, use the tester to read the pulses. Count out the number of pulses, then lookup in the technical specs to determine what the counts means. Please let me know if you figure out exactly how to do this, as I am clearly unsure and would like to do it myself.
btw, on my 89 300te, you will not hear the fuel pump unless you turn over the engine. The pump will remain on for a couple seconds after you stop cranking the engine as long as you leave the key in the 'on' position.
checkout:
http://www.peachparts.com/Wikka/EngineControls
Robert