Ecumaster forum

Hello I'm running fit mode in OEM Ecu box (Marelli 1AP) using it as a plug and play unit in multiple cars. I cant connect additional wires as extra grounds so i have to manage with the Marelli grounding connections. What is the real meaning of connecting power ground (pin19) to a different chassis ground than the DET3 ground (pin11) ??

Also I'm using an external MAP sensor, what is the right way to ground it (chassis or sensor ground through ECu)?

Thank you on advance

Anybody??

proper grounding is VERY important, doing it wrong you can encounter problems with loops on grounding, as you already know there are 2 main grounds one is ecu ground and in most cases connector is close to original ECU (connected to chassis) second is sensor ground and this one is separated, wrongly grounded device will have influent to sensor readings they can be noised or have offset from real readings

so for sensors use sensor ground

PS. https://www.youtube.com/watch?v=4YM1iwC6vhg - this is example in audio system but in general you want avoid noise and oversteer