ECU ground max current

[GTONath]

Hi,

I currently have 2 aem widebands (1 for each bank) wired up. I have the 5v output wired to the 02 sensor inputs, 1 on the mainboard and the other to the expansion board.
Now I currently have both wideband grounds going to the same sensor ground on the ecu.
My issue is that this causes the gauges to cut in out irradically, if I only have one gauge turned on everything is fine, I get an issue when I have them both on.

My thoughts are that the grounding current is too much for a single sensor ground, with both widebands on I've measured a peak current of 2 amps. This drops off once the o2 heaters have warmed up.

My question really is 2 amps too much for one sensor ground? I'm assuming it is and therefore each o2 sensor requires it's on separate sensor ground. Fingers crossed I've not damaged anything.

Thanks in advance.

Nath

[Raymond_B]

You do not specify which ground you are tying in to the MS sensor ground. Is it possible you are tying in the O2's power ground and not the sensor ground to the MS?

From the manual

"The better controllers offer a signal ground which should be connected to the Megasquirt sensor ground. Other
models require grounding to the engine block only. Consult the directions that came with your wideband
controller."

[racingmini_mtl]

If you have a single ground wire on your controller, do not connect it to the Megasquirt. There is way too much noise and too much current. Normal sensor currents are in the mA range not A.

Jean