View Full Version : How much noise is in a automobiles ecm?

05-20-2006, 09:54 AM
I would like to hook up my project in between a car's ECM and injectors, to count the pulses. I wander how much bounce or noise the ecm has controlling the injectors?

05-21-2006, 03:14 AM
How much noise does an animal make when you give it a bath? How about the make model and year of the vehicle? You will probably need something in the circuit to condition the output of the ECM.

- Stephen

Jim Richey
05-21-2006, 03:26 AM
Hello Rog

You will find quite a bit of noise in the injector driver circuit.This is mainly because the injectors are solenoids,coils that induce stray currents at a sometimes problematic level.
The on board ECM is made to filter out the trash.
The safest route to pull a signal from the line might be with an optocoupler.

Good Luck, Jim Richey

Thanks, Parallax!