Thread: ground for wideband when using nismotronic breakout box

you do not need to ground the breakout box unless you are trying to ground from the breakout box..

Yeah the tuner will likely remove your o2 sensor and use their own. Just make sure your exhaust is sealed well, it will throw off the values otherwise. Good luck tomorrow.

still having issues getting the aem wideband reading correctly in nismotronic

After looking around online, i found a wiring digram that shows the brown wire in the AEM harness as the 0-5v ground..so i assumed that this wire was the one which needed to be grounded to the ecu ground. Well, i just finished soldering and when i went to start the car the display on the AEM gauge flickered and went dark. I havent been able to get the gauge to work since...even changing the wiring back to how it was..
i guess i fried the aem unit
i have a new one on the way but i NEED to get this thing wired to the adc inputs and show the correct readings..

has ANYONE actually wired up a AEM uego wideband to a nismotronic adc box and had it all work correctly?

the only wire I am sure of is the white signal wire connecting to the adc input

thanks for the help

You do realize there are settings to adjust it so it matches right?

yes..but the readings are completely different

in nismotronic they fluctuate wildly while on the gauge things are pretty steady

the numbers in the software dont even come close to corresponding to actual numbers on the gauge

john said i should wire the aem wideband to the ecu ground which i thought was the black wire.

Wire the AEM ground to the IM

The go in and change the settings in the Nismotronic. You really shouldn't have to change much from John's settings from what I have found (wired up AEM, Innovate, and the Haltech wideband setup).

Also, the sensor itself may be on it's way out. Either way, you may be overthinking this. It's (literally) 4 wires

yes i was overthinking it...i had tried everything using different grounds and using the ECU ground to try and get the values to match but never had luck. I stopped trying to get the wideband working with nismotronic for a couple months until today..
did some looking around and saw this diagram:

so i then started to think the brown wire on the AEM harness may be the one that needs re-grounding.

...thats when i fried the aem

i have a new aem coming tomorrow. After i wire the white wire to the adc input and the black wire to the ecu ground (or IM) i will check the software to see how far off the numbers are..
Ill be back

thanks for the help guys

Wire the red wire (12v for the AEM) to pin 38 on the ECU - this should be a switched 12v source at the ECU.

Wire the black wire (ground for the AEM) to pin 39 on the ECU - this is the ECU's main ground source.

Wire the white wire to the ADC breakout box. Any input will work, just make sure the connection is solid and there isn't much "excess" wire coming out of the screw terminal that could be hitting anything else in the box.

I have wired numerous AEM widebands in this fashion and they have all matched reasonably well between the ECU and the gauge.

What you are trying to do here is minimize the voltage offset between the ECU and the wideband so the readings are more stable.

If you have a different color schematic then this one, then we might need to do things a bit different. But your basic AEM UEGO will be wired as indicated in this post.

thanks for the specific pin #s..i should have no problems wiring in the new AEM


edit: so after removing the old gauge and all of the wiring I found out why I was never able to get it working properly.. The previous owner cut the line from the gauge to the 5v output and whatever wire I was using this whole time wasn't even live..
so that would explain why the values seen in nismotronic weren't even close to the values on the gauge. They also had the power and ground feeding through the EGT gauge next to it, then going to the wideband.
Happy to be re-doing all of this wiring so I will know its correct

its amazing how well things work when you wire them up yourself


I just got the new aem wideband installed, wired it into the nemu breakout box...everything works perfectly