a Steering issue in gen 4th 2016

That noise would drive me crazy too, especially with hearing aids that emphasize the high frequencies.
I hear nothing like that on my Gen 4 purchased last October.

 

I watched the video that park uploaded today. The problem I experienced is kinda different, the sound is more like plastic rubbers each other and it happens when I turn left or right to some a extent. A dealer shop finally changed a ring-shaped stuff under the steering wheel, surprisingly the problem was not solved!!! WTH. Today I got my car checked at another dealer shop, the staff told me they suspect the problem is from the power steering, this time they are going to change that power steering within two weeks after they get the part shipped out from Toyota. finger crossed.

 

Your "crying rat" sounds like a PID loop that's gone into oscillation. I wonder if Toyota turned up the steering assist for the Korean market. Too high a gain leads to oscillation. Besides the annoyance this could burnout the power steering motor.

You could test this theory by pulling the fuse to the power steering. If the sound remains it's something mechanical. If the sound goes away it's related to the power steering. Obviously the car would be difficult to steer so use great caution if you try this.

 

That's the exact same noise as my UK car!

Posted via the PriusChat mobile app.

 

Am I understanding you correctly?
Replacing some steering column parts resolved the issue for one person. The old part could have been defective or the new part could have had a design improvement.

Since this is only one particular case, it is not clear that this will resolve the issue for other owners with the problem.

 

No problem. I just tried to make sure I understand.
Thank you for your patience & taking the time to tell us about this problem.

 

A PID (Proportional Integral Derivative) loop is a common control method using negative feedback to control a value. In this case the torque delivered to the steering rack based upon the torque input to the steering wheel. PID control loops can exhibit unstable behavior if not tuned correctly or if bad feedback is received.

I suggest the sound you are hearing is oscillation in the steering assist motor due to control instability. If the feedback sensor in the column is producing too high a signal or if the signal is delayed in time (phase shifted) the system could break into oscillation. Parts at the outer edge of their tolerance combined with poor assembly could do it.

Don't try to explain this to the dealer. Just tell him to throw parts at until it's fixed. Please report back and let us know.

 

Or if you are using lka, try turning it off.

 

Lka = lane keeping assist

 

My Prius started doing this today! I hope it is a fluke and will check it again in a bit but as I was driving at around 45mph slight movements of the wheel caused this sound. Turning the wheel as if to pull into a parking space does not produce this sound.

This prius was built in May of 2016 and is a 4 with the advanced tech and premium convenience packages

 

So far, my 2016 built in 7/16 and bought in 8/16 with 1 mile on the ODO, now has 3,100 miles and I haven't had this noise.

 

I actually noticed my car doing this recently. However, it also happens even when the car is parked but still ON. It doesn't happen all the time, but has happened enough for me to notice. I haven't had the chance to bring it up to the dealer, but I should try to get a recording next time to show them as evidence. I am at 30k miles on a 2016 three touring.

 

I've been reading up on this. The 4th Gen uses Electric Power Steering (EPS) made by JTEKT. See a pic here https://www.marklines.com/ja/report/statics/a/rep1478_020_l.jpg. EPS's are getting more advanced in general, possible a little ahead of themselves. JTEKT’s EPS uses an assist control algorithm called J-ISM (can't make this stuff up). J-ISM detects vibration coming back from the wheels and tries to actively suppress it before it reaches the steering wheel. I guess we won't know when our tires are cupped or belts shifted anymore, after all ignorance is bliss. Anyway, J-ISM has more tricks. It uses variable phase compensation to stabilize self-excited vibrations or oscillations. Phase comp, however, is reduced at low torque to improve steering feel. See paper here http://eb-cat.ds-navi.co.jp/enu/jtekt/tech/ej/img/no1003e/1003e_07.pdf. This seems to be the region where people are getting the squealing sound.

So, we drive a fancy high tech car with high tech problems and high tech annoyances. Turn up the radio!

EPS without 17" wheels 8965047560
EPS with 17" wheels 8965047570

 

ROFL!!!!

 

Hi all - it seems the noise in the video is coming from plastic rubbing against plastic. It is really annoying!

I have instead another noise coming from somewhere behind the steering wheel - I cannot understand if it is from the steering column or inside the dashboard plastic.

The sound happens above 60km/h // 40 mph at specific RPMs of the ICE and sometimes depending on temperature. The noise is like a piece of flat plastic vibrating, resonating to some other vibration in the car.
I tried touching anything reachable by hand on and around the steering wheel to see if I could stop it, but with no success. I also tried (and it is dangerous to do!) to adjust the steering wheel while driving to see if it made any change, but no success with that either.
Never had this issue in Gen3.

I was at the dealer for another reason (left front brake makes a repetitive noise when braking at low speed) and they told me to let them know next time I go for service if it is still there, because Toyota is asking them actively to report any noises. They also said to bring any videos I can make to see what it is. If they need to do something, they told me they will likely have to unmount the dashboard - which honestly I don't want them to do as that will introduce many more noises IMO!

My car was bought in June 2016, so I suspect it was built between Feb and April of the same year.
I should have waited a few more months to get it, but a service and change of tires on my Gen3 was coming up, and didn't want to invest money on it anymore.
I will try to make a video of this noise and post it soon.

 

The month it was built is on a drivers door sticker.

 

I checked on the sticker, but there is no explicit indication of a manufacturing date. Is it encoded in a special way? e.g. last year digit and calendar week?