EMU Classic - AEM Lambdatool

EMU BLACK / CLASSIC
1

Hi everyone,

first of all, here are the hardware details:

ECU: EMU Classic

Wideband Controller: AEM X-Series UEGO 30-00300

Engine Harness: new

Engine: 1.8T AGU

I am currently in the process of tuning the vehicle. Since there is no CAN bus available, I connected the AEM wideband gauge to one of the EMU’s analog inputs in order to read the 0–5 V analog signal.

Here is the issue:

In the EMU software, the lambda value fluctuates heavily. According to the logs, the analog voltage is very unstable, even though the AEM gauge itself shows a perfectly steady lambda reading.

AEM wiring setup:

Red = 12 V switched

Black = chassis ground

White = analog output → EMU Analog Input #1

Brown = EMU sensor ground

No matter how I wire it, the lambda value in the EMU keeps flickering and is unusable for proper tuning.

Does anyone have an idea what could be causing this?

2

have you tried a common earth/ground for the devices ?

having different earth/ground sources/places/points can give issues.

i have a earth/ground bus bar for all electronics to connect to.

3

Have you set the right voltage?

I connected it the same way and it works

0V=7,31 AFR

5V=19,19 AFR

4

broken signal output on the aem gauge

5

„Yes, the values were set correctly.

In the analog input log you can clearly see that the value fluctuates heavily, regardless of the lambda value…“

6

“Thanks. I’ll now check whether the issue is really with the display. I’ll take it apart and, if necessary, resolder the pins. Did you have the same problem?”

7

So… I disassembled the display and resoldered all the pins, without success… I’ll make a few more attempts in the coming days and keep you updated.:face_with_raised_eyebrow:

8

So, long story short: I’ve tried every possible wiring configuration and no matter how it’s connected, the signal just doesn’t stay clean. Sometimes it looks fine, then it becomes completely noisy again. I’ve now switched to an LSU 4.2 and basically given up on the AEM gauge – at best it will be used as an auxiliary display. A pity, really.