i had the brake message come up..
but this was only after pumping the brakes several times until the pedal was firm WHILE the car was off.. I pushed the start button two times without depressing the brake. the message showed up.

I was able to start the car normally.

^is this the expected response from the car given the sequence of events i described in my post?

 

I bought my car, 7/4/2017. I dropped off my 2017 RX350 to the dealer on 9/5/2017 because thus far on THREE separate occasions I got the “braking power low” message. The first technician tried to tell me that I didn’t press the brake hard enough when I tried to start it—Ummm….nice try, but NO. On 9/7/2017, when I picked up my car because “everything is fine” I asked the technician, “At what point do you determine that there is something wrong, because the way I look at it, a brand new Lexus with less than 2000 miles should NOT be having starting issues”. I asked this question five different times and each time he turned the conversation towards a different direction. Finally, he told me to take a video the next time this happens. I will be doing just that, in the meantime, I am going to call: 800-25 LEXUS to voice my concerns. I mentioned this blog and was asked if anyone had the "code" identifying the problem, if you have the problematic "code" PLEASE post it. I now have a beautiful, luxury, NEW Lexus, but have to worry about whether or not my car will start—sorry Lexus, we and I will be having more conversations down the line. #RX350 #Brakingpowerlow #Lexusstartingproblems

 

Does this brake issue affect the RX450h? This sounds very worrisome!

 

@ba-b4,
I'm unsure if this affects the RX450h, I have a RX350.

 

I had the exact same problem with my 2017 RX 350 with 3000 miles. I use my car every other day to take the baby to class. And each time the brake will get stiff and will not go down. Up until few weeks ago, one morning I got the message "Braking Power Low" and the car will not start. Got it tow to the dealership and got the brake booster replace (after 5 days in the dealership). Now today, it happen again. The car not starting after sitting for only 1 day in the garage.

I realized some people had it fix multiple times and still having the SAME problem and the car will not start. This is unacceptable. I wonder if it consider a lemon car.

 

Your vehicle is still covered under warranty. Have them check the brake booster

 

Do not know for sure but neither on my 450h units suffer this so far, but my 2016 RX350 did have this problem just before trading it.

 

Have the dealer adjust the stop light switch. All the ones i've looked at have been at the lower end of the allowable adjustment range. There is about a 2mm range you can adjust the switch, which translates to alot of pedal travel. I guarantee this will help make it easier when the booster is out of vacuum and you have the hard pedal.

 

Just experienced this prob briefly yesterday. 17 rx350 with 1002 miles

 

its just an issue that occurs. There will be a recall when they know what has been causing the issue. My RX is almost at 10,000 miles and I have not had the issue since around the first oil change. Seems to me like it occurs when the car is brand new but it seems okay to me been a few months. Just give it a few weeks and see what happens.

 

It happened again.
I purchased the car on July 24th, so it is about two months old now. I posted about the problem when it first occurred (Aug 10) and the dealer replaced the battery. But the problem is back. It seems that if I leave the car for more than two days in the garage, the problem occurs. I use the car everyday for work, but on weekends I like to use my other car. I can't believe this is happening.
Shame on Lexus for still not knowing how to resolve the issue; seeing that more people are having this issue since my last post. I would not recommend this car to anyone.

 

Were you not able to start the car? Every time I saw that message, it disappears after I start the car. It did require more pressure to step on the brake, but you don't need to depress the pedal all the way.

 

If your car is still within 4 years or 50,000 miles, it will be covered under warranty. Guys it's the dang brake booster.

 

I just got the error message for the first time. 13k miles on the car. AAA checked the battery and there was a dead cell. For those who got the brake booster replaced, did lexus replace/check the battery too?

 

Hi - Anyone know if there is some major initiative/recall from Lexus yet on this issue?

I own a 2017 RX350 (purchased July 2017) with 5979 miles on it. This issue has occurred twice since buying it; most recently this past weekend.