1994 BMW 540i computer connection

Because there is no OBDII connection on your 1994 vehicle. You will have to use the 20 pin connector under hood to extract the diagnostic trouble codes and you will need compatible diagnostic equipment. There are several makers of equipment, Baum, Peake research, Autologic come to mind.

[quote:2138b8dfbe="willeo"]Computer problem
1994 BMW 540i V8 Two Wheel Drive Automatic 81,000 miles

I want to use my obd sensor tool to find out why the check engine light went on....I can't locate the terminal plug in site. Any ideas?[/quote:2138b8dfbe]

Because there is no OBDII connection on your 1994 vehicle. You will have to use the 20 pin connector under hood to extract the diagnostic trouble codes and you will need compatible diagnostic equipment. There are several makers of equipment, Baum, Peake research, Autologic come to mind. Check the O2 sensor, it will command the check engine light on.