UX hybrid brake stroke sensor noise

[Guest]

Hi all!

I'm from Singapore and I guess the UK and Aussie forums are the closest being RHD models. 

I collected my UX250h in May 2019 and noticed when I was driving, there's a clicking noise whenever I step the accelerator (https://youtu.be/WsojdVad158). Upon googling, this issue seems to plague another UX250h owner in the States (https://www.youtube.com/watch?v=yIIPv4u1-kc) and another Camry Hybrid owner (https://www.youtube.com/watch?v=NGZtvqLnz8s). This problem seems to plague the newer Toyota/Lexus hybrids on the TNGA platform as I guess they use the same part from a defective supplier for some batches. 

The noise can be produced with the following permutations met -
- Car must be switched on.
- Transmission must be in 'D', 'R', or 'N'.
- When the car is switched off, depressing and releasing the brake pedal will reproduce the clicking noise.

I've tried diagnosing it myself and it was actually coming from the brake pedal assembly. I brought it to my dealer and did a diagnosis together with the technical manager. We both confirmed that the noise is coming from the brake stroke sensor. It is causing the clicking noise every time it receives an electrical signal (when the accelerator is depressed or brake pedal released). When using the dynamic cruise control and when the car accelerates and decelerates itself, the clicking noise can be heard too. The noise can even be 'felt' if you rest your feet on the brake pedal as the stroke lever 'jumps' when it clicks. We confirmed that it was the brake stroke sensor as upon unplugging the wiring harness from the stroke sensor, the clicking noises disappears completely; but of cause, all the error messages start popping up. 

The dealer had mine replaced with a brand new sensor but sadly, the clicking noise was still there. I requested my sales consultant to allow me to retest the UX250h demo car (which I tried earlier prior to my purchase). Upon testing, I realised the clicking noise was there too, however, it was extremely soft to an extent where I can accept it or rather, acceptable for normal operations. You'll have to strain your ears pretty hard to hear it click. We (the technical manager and me) then agreed that the clicking noise is 'normal', but mine is clicking at an unacceptable volume. The diagnosis also confirms that it is an electro-mechanical noise and not a malfunction, just inconsistencies with the part throughout several UX hybrids. The pedal spring, brake light switch and, brake simulator and brake booster master assembly works just fine.

Nevertheless, my dealer have forwarded videos and sound recordings to TMAP (Toyota Motor Asia Pacific) - in this case for Singapore for further action. I've been further updated last week that TMC (Toyota Motor Corporation) is aware of my issue. I do hope there will be a proper solution for it.

Have anyone here faced this issue and whether their dealer have any solutions?

PS: I've attached a picture of the layout at the pedal assembly.