UCON Flex Advanced Engine Management System

No codes on mine!

I did also have a P2241 recently, but I used the DTC flow chart and followed to tests it outlines and the driver O2 sensor was open circuit internally.

Not saying UCON is without its flaws, but it’s not always the first thing I blame for a DTC.

 

Same problem for me kinda. Random p0300 when Im in az, when im not in the heat it never happens

 

Gadget told me to get my temps down and watch the spark timing come back. It's finally cooling down, I think it's only gonna be 90 today.

 

Both front bank 1 and 2 are denso 29050 (03u21).

 

Sounds like an OEM part number. You said that you've replaced all the O2 sensors. So you bought brand new from the dealer? $$$

Some of the diagnostic information in the Toyota repair manual refers you to use a scan tool to monitor data stream. Such as O2 sensor voltages, etc. The issue with that in our situation is that the UCON is sort of "in the way" if we are reading information from the OBD2 port, such as in your case via the UltraGauge. The UCON is sending unicorns and rainbows the OEM ECU. The OEM ECU is sending the data to your scan tool via the OBD2 port. So depending on what value you're looking at, the value is what the OEM ECU sees, not what is actually happening on the other side of the UCON.

Fortunately, uTune logs what is sees and what it's feeding the OEM ECU. So say, you're looking at O2 sensor voltage. The uTune should show both "versions of the truth" in the log.

I know you were having trouble figuring out how to do a data log. Did you ever figure that out? A data log is the best information you can provide to Scott for troubleshooting. So the best thing you can do is figure out how to reproduce variables that cause the check engine light and then try to capture it in a log. These intermittent issues are tedious to catch in a log, though. So it takes a good amount of patience.

 

To take a datalog open utune on a laptop while plugged in via usb to the ucon.
Disclaimer....with a passenger click the "sample" button in utune. This will take a 60 second datalog.

It's in the upper left hand corner.

 

I got the 02s from Amazon. Right now it's showing rich on bank 2. Way rich. We're pulling the ucon to see if it evens out without it. I wont be driving just idling.
The picture is of the factory harnes plug that goes in to the top of the ucon. Notice the bare wire.

 

Fuel trims even out without the ucon.

 

Were fuels trims off at idle with the UCON?

 

I dont mean to insult your knowledge as I have no idea what your level is but you HAVE to test with the exact conditions so you are eliminating one variable at a time.
If your afr's ore only off at higher throttle settings with the UCON but fine at idle and you only test idle without the UCON it means nothing.

 

Yes. But im reading the ultraguage. With the ucon it said bank 1 was +2.3 and bank 2 was -14. Without the ucon everything was way negetive but even -23 for both banks.

 

That bare wire with tape is just a shield wire. To send to ground the induced voltages caused by magnetic resonance.

 

-23 may be max for the ultragauge which would render the test invalid.
I'm not trying to defend the UCON, just trying to help isolate the problem.

 

I was just saying "at idle" for the numbers. If i give it gas the trims go more rich on bank 2 and consistent on bank 1. I did apologize in advance for my lack of knowledge lol. My levels are not up there with this stuff.

 

I just had a p2238 with factory o2 sensors so I tried replacing them with Bosch sensors I bought off Amazon.
After install I got a p2241 and that bank ran crazy rich when I got into it. Like 3 points rich.
After talking to Bosch, they said they sometimes purchase from other manufacturers and if not bought from a Bosch authorized dealer then there is no warranty.
Funny thing is the sensors I bought from Amazon had an "AD" hand engraved into the sensors. I didnt think anything of it originally but after I filed a return through Amazon I realized AD was the company I bought from.
So most likely they are buying out of spec reject parts on the cheap, engraving them, and selling them hoping they work!

After that fiasco I bought 2 NGK 24661 o2 sensors and guess what....its the exact same sensor as the Bosch but these are working perfect so far (only 50 miles since replacement)

Bottom line is if you bought for a discount you may have bad o2 sensor/s. Definitely worth pursuing to rule out.
My truck acted really funky with a bad o2 sensor because it cant determine what it needs to do unless given an accurate signal.

 

No worries man...we are here to help!

 

I've swapped 02s side to side, extension harnesses and coils. The problem stayed on bank 2.
I also know the kit was installed in 2015. However the ucon has a date 1-11-17 indicating its been replaced. I bought it February 2017.

 

Hmmm, well that changes things doesn't it. What history does Gadget and Scott have of this truck I wonder?

 

Right? Ninja Explosion has a little on here from when he owned it but nothing juicy. Mostly just selfies.

 

Right now ive got the ucon out and im thinking of sending it to Gadget for inspection.
I emailed him and sent a picture of the date and serial# on this ucon along with a summary of what we did today. We'll see what he says.