How do I use '89 E34 535i diagnosis port?

[Jazz_89]

Hello dear BimmerNuts,

does anybody know how to read engine codes, or perform engine diagnosis via the diagnosis port of the E34 535i? I am hoping to be able to extract the LongTermFuelTrim or similar parameters.

Thanks alot :)
Jazz

[shogun]

A normal tool will not work, that is pre-OBDII system. Some people use the interface from Gert rv8flyboy, see here http://www.interfaces4beemers.net/

The 1989 M1.3 Motronic is stone age of diagnostic, the number of fault codes you can retrieve is very limited. Same as my 1.2 Bosch end number -156 for the M70 engine.
In case you have a U.S. spec car, then you can make a stomp test to get the fault codes, details on my website below.
The Peake tool will give you basically the same as the stomp test.

[Jazz_89]

Alright, thanks for the help !