Cruise / Lane Assist / Sensor "System Malfunction"

I'll give the update on the situation now. I took it to a professional ADAS shop, they review it, did some calibration on the front sensor, but then they noticed a weird steering wheel code

X0455: Steering Angle Sensor Wrong Installation​

Interestingly I found a Yaris guide with the same code that gave a description of possible fixes, which I did. Potentially the clockspring sensor was rotated incorrectly on installation
Toyota Yaris - Steering Angle Sensor Wrong Installation (X0455) - Vehicle Stability Control System

So I will bring it back to the shop and see what they can do next with this.

 

Appreciate that, I will definitely give you the full update.
864A1-47031

Since I was spending a lot of money on shop diagnosis, I decided it would be a wise investment to get a quality OBD2 reader that could handle the Gen 5 Prius. I ended up getting this mode from Amazon which claims it specializes in Toyota/Lexus

So I ran some testing today, and it show ALL DIAGNOSES were fine (no error codes at all). So I suspect its something deeper in sensor calibration or something like that, which unfortunately may not be explicitly shown as "error codes" on this scanner. Here are some possibly weird things I noticed? Steering angle signal shows "666 degrees" approximately with the wheel and tires straight ahead, however the Steering Angle Value correctly shows 0 degrees. So I am a bit confused here, my next step is to try the actual Toyota Techstream, but possibly this will show more info and more error codes that this Launch reader is not showing. Hopefully by weekend I will be able to do so, and definitely will post all results and info here

 

interesting video, thanks for sending that. I was able to take off the wheel and inspect the clockspring 2 days ago, I wasn't able to see the "red marker" that he mentions, and I even took some time and spun it around several times before returning to the original configuration. Does anyone know if this "red marker" is still used for alignment in the 2023 Toyota models? because this video was from 2010, so it seems likely they changed the part since then and it may not use the same conventions? Because I definitely did not see anything red through the windows of the clockspring thing.

 

thanks so much! I will take it apart over the weekend again and get some pictures and verify it matches up with your document! this should help a lot

 

Here is the update now. I was able to use the scanner tool (didn't show any errors) and Toyota TIS Techstream software which showed the steering angle sensor incorrect installation from before. So I disassembled the steering assembly to inspect the spiral cable assembly, and it doesn't even look like the pictures I have from the Toyota repair manual. The manual shows the "window" around the 9 O Clock angle, and mine has it on the 5 O Clock angle. So something is really strange here. I need to remove this completely and inspect to make sure its the proper part #, because its possible the shop installed the incorrect part on replacing the airbag?! It seem to fit perfectly with the cables however, so I am a bit confused.

So I need to remove it and do further inspections Or possibly the sensor was installed incorrectly onto the assembly?

 

ok, update on this. I have spent about 5 hours working on it in the past few days, and also having access to Toyota Techstream software now. I completely removed the spiral assembly multiple times, readjusted it and then reinstalled it.

I am fairly confident that its related to the Steering Position Sensor error code X0455. I was able to "clear" this code out one time, so everything reset, and all the ADAS messages completely disappeared and it seemed to function properly for a few minutes, until the X0455 code kicked back in again, which triggered all the other ADAS warnings to come on. So apparently these ADAS systems (Cruise Control, Lane Assist) are highly dependent on the steering wheel angle position sensor functioning correctly. So if there is an error message with this, it will disable all the ADAS systems as a result also which was giving all the warning lights.

So as of now, I am just focusing on diagnosing and fixing this X0455 "Steering angle sensor wrong installation" issue, which is triggering all the other warnings . Its either the sensor itself that is bad, or some of the cabling attaching to it. I probably will buy a new replacement sensor now and see if that solves the issue, and if so then case closed.