Wondering if this is something I've just never noticed, or if it is a problem. Recently it seems I am getting a vibration like sensation coming through the brake pedal after I come to a stop. Almost like the regenerative braking "stops" and I feel it in the pedal. Is this just something I've managed to overlook? Or something that isn't right?
Thread bump. Just started another thread with this too. In my 2010 Prius I've noticed the same thing. Conditions seem to be: 1) Approaching a stop and while initially stopped for a few seconds 2) Vehicle in drive 3) Air Conditioning on high speed. I can feel a higher pitched buzz in the brake pedal, as well through the floor with my left foot. If the air conditioning is turned off, it goes away. If I shift to neutral, it goes away. If I release the brake and roll forward it goes away, only to return when stopped again. Anyone else having these symptoms? For what it's worth, I also have a 2007 Gen II and it has never done this. Also, it is definitely not the brake accumulator running.
I only really notice it in "around town" driving. My commute is mostly highway, with some gridlock, and I haven't noticed it this week. About to go out now to grab dinner and we'll see if I notice it then. Unfortunately I think this will get the brush off from the service department unless it is a known issue. I've mentioned other things that cannot be reliably reproduced and you get the "well if you can't reproduce it...." line.
It is a known issue! Just took Elsa to the dealer today and described the problem as I have here. When I got her back the advisor said they updated the brake and ABS software to a newer version and it should greatly dampen, but not eliminate the noise. Drove 30 miles this afternoon and didn't notice it at all, so I'd call it a success. My service invoice reads: "EL1034 REFLASH BRAKE ACTUATOR SKID CONTROL ECU" "Noise caused by brake accumulator building pressure. EL1034 recalibrate ABS ECU with updated software to reduce brake noise" The only thing that confuses me is the noise itself wasn't coming from the accumulator. When it would make the noise I pumped the brakes to try to isolate the noise, but while I heard/felt the buzzing I also heard the accumulator activate to recharge the brakes from the pumping. But alas, no more noise. Hope this helps!
One thing Ive found about these brakes is they are sensitive. Under normal braking, coming to a complete stop with the brake pedal pressed the entire time until dead stopped, I not only feel an abruptness but also hear a buzzing sound. To prevent both, I let up on the brake pedal lightly just before dead stopped and then press the brake again to come to a complete stop. Butter.
Thanks for the update Cessna. I haven't had it pop up in a few days, but will mention it at my service.
