Wideband stuck at lean; even at startup, unplugged

[silvia910]

Does anyone have any idea why my gauge reads all the way lean always? Some insight would be nice. Checked continuity of all wire on sensor harness, checked out. Replaced sensor with Bosch 17018. Even did brake cleaner rag test, gauge still always reads lean and doesn't move. Even with the sensor harness unplugged from back of gauge, when ignition is turned to on, it would run through the starting scrolling sequence and then just immediately reads full lean (---). Apparently it should read 14.7 initially, with sensor harness unplugged. Gauge is set to p0. Any ideas? Also, can't seem to find a replacement gauge anywhere, only everything but the actual gauge.

[jr_ss]

How about we start with the basics.. What type of wideband is it? Pictures of your setup? Do you have the right sensor for the unit. Have you done a free air calibration?

[silvia910]

Oh wow, kinda rushed through that intro.
It's an AEM UEGO so no free air calibration necessary. Power is connected to cig lighter. Ground is connected to ebrake-to-chassis bolt. Ran perfectly for ~ a year. Then..it was initially reading mostly 14.7 all the time, sometimes spiking to full lean due to a boost/vac leak or fuel issue I'm trying to figure out right now. But never never showed richer than 14.7.. Eventually it was 90% of time always at 14.7. Figured sensor was on its way out so pulled the sensor. Completely covered in black shit, most of the holes being covered with deposit. Replaced any ways with Bosch 17018 sensor. Also noticed part of sensor to gauge harness was burned/rubbed through so I cut, stripped, and soldered lines together. Continuity checked out on all wires. Since reconnecting everything, started having issues as described in OP. Even with brake cleaner rag test on either sensors connected, with sensors warmed, never moved from full lean. Even called AEM and explained the issue, especially the gauge showing full lean at start up with sensor harness unplugged, instead of sitting at 14.7.. They said most likely gauge, but he wasn't really much more help than suggesting I just send it in for a $50 inspection...

[AnonymousBlackX]

Honestly I would redo my ground when mine was grounded wrong did the same thing

[Croustibat]

"Power is connected to cig lighter" may be the problem, cig lighter from these days usually cant provide much more than 5-10W.
If your controler heats your WB sensor (they usually do), it is going to use approx 25W for that.

You might have just enough juice to power the dial, but not enough for anything else. I used the same wire at first for my gauges but they would just do the opening ceremony. I ended up making a new wire + breaker from the battery to power them.

[corkscrew]

Your sensor could have also went bad. Check the easy stuff first; grounds, connectors, etc. Then verify wether or not the sensor itself is functioning correctly

[cotbu]

I'm not a huge fan of the aem uego controller at all. So I don't know, if you can even do this? Hook it up to your laptop and see if the controller is still functioning or if the gauge is just malfunctioning. Obvious if the readings between the two are different.

[silvia910]

I plan to redo my power and ground tomorrow morning and I'll report back with results.

Cotbu, do you mean hook up the gauge or the car to my laptop? I do have a ecutalk consult cable but that's a whole other thread and issue I'm having. I can't seem to get my cable to connect with my laptop. Downloaded the ftdi drivers and went through the instructions with deleting old drivers, downloading new drivers by choosing from specific folder, changing com ports, etc but can't seem to get the program to connect to my consult. Trying with Nissan datascan and ecutalk.

[derass]

Replaced sensor with Bosch 17018. Even did brake cleaner rag test

I diagnosed a failed sensor using the rag test but used gasoline instead. That Bosch replacement concerns me. The AEM sensor has an additional resistor when compared to the Bosch.

...cig lighter... cant provide much more than 5-10W.

...controler... is going to use approx 25W for that.

I plan to redo my power and ground tomorrow morning and I'll report back with results.

I'm a little embarrassed to say this, but my wideband takes power from a random small gauge wire under the dash and hasn't given me any problems in over 5 years (apart from the sensor failing due to prolonged rich conditions). I somewhat doubt the wiring is the problem.

[silvia910]

I don't think the sensor is the issue. There's been many confirmed reports of that Bosch sensor being a direct replacement for the one used with the AEM UEGO. Considering the gauge, with the sensor harness disconnected from behind, should sit at 14.7 with the ignition on (to signify it's working) leads me to believe that it has something to do with the actual gauge/controller itself.