I am not completely clear on the BMW modification for the serial interface cable.
I understand the connections for DSR, RI and the 1.2k resistors to IGN and +UB

Is RTS replaced by DTR connected to the existing transistors and then to the 'L' line??
Is a schematic available for the BMW modifications?

only reading...

you must have an switch with common contact for the RTS/DTR cable.

is an three contact switch, the middle contact ist the contact from the pcb.
then you soldered the DTR/RTS cable on the switch left and right.

The other switch ist the connection between 7+8. This is only an On/Off switch.
At off the Bridge isn´t on, at On the Bridge is from 7 to 8.

The resistors are not important, you can use Inpa/Ediabas also without these resistors.
It´s better/professional, because the Programm behaves it like the original IF.
It shows professional... the LED in Inpa is checked, when ignition is on...

In Inpa/Ediabas are blinking a LED and says "Ignition Off", but you can ignore that, it works yet, at least in my case.
(without resistors)
I rebuild the Resistors too.

I have the same Interface...converted...

Thank you Bernd.
I think I understand. I only want to use it with BMW for now. So I will not need the switches.
Is the attached schematic correct for BMW only?

_________________
Werner
BMW 318ti //M

I think it is OK .

Thank you Bernd

_________________
Werner
BMW 318ti //M