powering additional sensors using 5v ECU power

bsclywilly · Post by **bsclywilly** » Sun Mar 14, 2010 9:26 pm

What is the limit for powering additional sensors off the ECU 5V out?

I'd like to run additional MAP and possibly 2 or three additional sensors. I'm guessing these sensors draw around 100mA? And the voltage regulators are probably 1A? Please confirm.

P28/s300

fly_n · Post by **fly_n** » Sun Mar 14, 2010 10:30 pm

If it were me,i'd probably take a cue from the 5V rails out of the ECU being dedicated ,as they stand at present,& leave them alone.

Its easy enough to set up a 5V source externally....

boostedcivicsir · Post by **boostedcivicsir** » Tue Mar 16, 2010 4:14 pm

i set up a fuel pressure sensor to datalog. i got the 5v reference from the tps, i left the map signal alone. i dont know if you would want to run more than 1 more on that circuit, but for what it is worth i have had any issues.

Post by **Hondata** » Wed Mar 17, 2010 9:21 pm

A sensor should be more like 10 mA. The voltage reg in the ECU is probably around 250-500 mA, but this is running the whole ECU and all the sensors...

Jaker · Post by **Jaker** » Mon Mar 22, 2010 10:07 am

The circuit board inside the ECU "shares" the 5 volt feed and the ground for the MAP with many other sensors. The traces/tracks on the board go to both D19 and D20 for VCC1 and VCC2, and go to both D21 and D22 for SG1 and SG2.

I think if it were that critical, there'd be some sort of differentiation on the circuit board with filtering in between the circuits. I think the goal is to prevent cross chatter of feed in the actual wires that run through the car to the MAP versus the other sensors, but when you get right down to it, they end up in EXACTLY the same place.