Installed custom VEMS plug and play (55pin Motronic) to Porsche 964 Tiptronic, works fine but Tiptronic is in limp home mode due to the missing fuel injector pulsewidth signal.

If it needs fuel pulsewidth signal, why not connect a "fuel injector output" ? Tried that, still limp mode. Car has bigger injectors and it seems that pw is too short for it. Since it is injector pw, signal is likely switched GND

I connected the P259 pin 4 (ch0, with pullup) to the corresponding pin (pin 32 on Motronic 55pin connector) and configured boost gauge output hoping it will settle for just some kind of square wave signal but Tiptronic is still in limp mode.

Any tips how to proceed with this? I think fuel injector load output signal would be useful for many cars, even Audis use this to calculate fuel consumption, many Porsches etc. With display you can just ignore it but with tiptronic it ruins the driving -> cannot be ignored...

Please produce some scope measurements of the stock ecu having both one injector signal on one probe (ch1) and the pin32 mot55 signal on the other probe (ch2), and take a few (clearly marked by filename) scopeshots @ idle rpm, 3000, 5000 rpm.

Without proper measurements its hard to know whats needed at all.


Perhaps I can ask customer to install back original DME (easily done since PnP?) and to scope the output signal from original DME? PeepPäädam?