Steering angle sensor

I have a code on my 17’ that reads. “Lost communication with steering angle sensor module” code “U0126”.

has anyone had this issue? My battery died about a month ago, and this code appeared after I jumped it. And has been there since. I replaced the battery and checked all fuses. The part itself is anywhere from 200$ to 350$. Just trying to avoid that cost if I can. Any thoughts would be appreciated.

 

How did you read the code?
Did you clear the code, and it is returning?
If so, how long/when does it return?
If truck currently doesnt have the steering sensor, I would expect more codes/and lights (but I havent researched it more carefully)

 

Yeah, U codes are never cool.

OP, No mice / critters?

 

My local shop read the code, cleared it, then it showed up immediately after starting the truck again. It has the sensor still in it, I can do the repair myself if it’s the actual sensor. Just trying to figure out if I have a loose connection, or a relay out or something like that before I take apart the steering wheel.

 

Not that I can tell, I work in the woods, and that was my first thought. But haven’t found any mice or nests.

 

If u really wanna avoid throwing parts at it. You'd need access to a wiring diagram and meter / scope. Check powers grounds and data lines.

 

Looks like the steering angle sensor is also the spiral cable. Pulling a couple of schematics now.

 

The steering angle sensor snaps to the back of the clockspring. However, for diagnosis you should be able to get at the wiring connector by just removing the steering column covers. Turn the steering wheel 90 deg each way to expose the column cover screws.

 

(I am blind, you told us its U126, so lost comm to skid control ecu.) Would help to know which code it was specifically, as it appears to have redundant power sources and codes for no-power... vs communication issue or internal sensor issue.

Notice there are at least 3 or 4 codes it could have been (U code vs C code, etc)

 

Thanks everyone! That schematic helps a lot. I assume ESS is the ground. And hopefully I can get in there, just taking panels off to diagnose. I’ll give this a try tomorrow see what I find. I should probably see 12 volts for the battery and IG. Does anyone know what voltage I should be seeing from the CAN’s

 

Afaik, you would need a scope. It's a waveform

 

This is definitely not my area of expertise.
That said, I do know CAN is a differential signal where the signals are differential (Line H > Line L is a bit vs Line H <= Line L) switching between the two states rapidly, so you wont be able to actually see that except with a scope. This encoding method provides very good immunity to common mode noise (where both lines get increased at the same time, etc).

That said, both Line H and Line L should nominally be pulled above ground by a couple of volts (~2-3 V above ground).

 

Does your TSS or whatever it's called, show you code setting criteria? They might even give you a known good waveform to compare against.

 

This is just Ctrl F on the 2016+ Service Manual PDF that is floating around. There is quite a bit of discussion on if U0126 occurs in addition to other codes. For just U0126 this is what i see

(not sure how useful this is)













CAN diagnostics (really need a 2 channel scope it seems like, a cheap Amazon one would probably be sufficient but still some significant cash)







Note, I assume that you are not getting the C codes that correlate to bad output of the steering sensor, or bad internal calculations for the steering sensor.

 

Good shit!

 

Toyota requires the steering angle sensor to be calibrated and memorized after the battery is disconnected (or it dies). I see this everyday

 

Wouldn't that be a C code and not a U code? U codes are usually failure to communicate right?

 

My battery died today and now I'm having this issue. Used the search button and it lead me here. Has there been a fix? Tried clearing the code and doing a zero point cal but it's not going away