After figuring out one bug another pops up.

Now I've got a problem with my AEM UEGO wideband. About a week ago, it would go from normal AFRs to reading extremely rich or lean, then display ----. It would constantly do that as I would accelerate. I chalked this up to a sensor going bad.

A few days ago, it was doing the above then completely stopped working. I had sometime today and pulled the wires to check them. None of them looked severed/damaged. Since I couldn't explain the lack of power, I respliced all the cables again and plugged it back into the MS3. Nothing.

I've checked all the wires and haven't found any damage.

I also ordered the same gauge brand new plugged it into the existing wiring. Not working.

My only two explanations are:

1) Either the MS3 harness or something on the MS3 board is not working as it should. How probable is this? MS3 Rev Built.
2) The old and new gauge are not working- The new gauge I bought looked like it was used even thought it was supposed to be new. So I can't verify whether the gauge is working or not.

Thanks guys.

 

Check if you have 12V on the white/red wire on the DB37. If you don't replace the fuse inside the ECU and find out why it happened.

 

The fuse being blown would explain no power from the harness to the gauge? Any known reason as to why the fuse may have blown? From what I recall, I haven't touched or changed anything when the gauge blew.

 

Usually, when a fuse blows, something upstream of the fuse has shorted. There's nothing upstream of the fuse inside the ECU, so my guess would be the sensor wiring, as the failure of the gauge before going out altogether would suggest.