Mr645

Had a problem last night with my NX.
I was coming up to a toll plaza for a small bridge to an island. I normally use a prepaid transponder but this bridge had a sign saying that the State transponder not accepted.

So, I turn on the brake hold feature (car in drive), unclip my seatbelt to get my wallet from my back pocket, and as soon as I did, the parking brake engaged and the brake hold turned off.

I tried moving the car to park, back to drive, lifting and pressing the parking brake switch, nothing. I ended up driving about 2 blocks, going through the toll plaza until I could pull over, the entire time the front wheels spinning as I dragged the rear wheels down the street.

I turned off the car and restarted it and the parking brake released.

Dealer is sending a tow truck to pick up my NX, the cannot explain what happened.

1halifax

In the manual if you have the park hold on and the driver takes off the seatbelt the hold will change to the parking brake. I think its a safety feature.

Mr645

Thats what it did, although I really cannot figure out how that is a safety feature. What does my seatbelt have to do with anything? All it did was leave me blocking the lane at the toll plaza.

corradoMR2

Actually it has everything to do with it. I think it operated as designed. The programmed assumption is the driver is exiting the vehicle and hence the safety mechanism (i.e. parking brake) engaged to ensure the vehicle does not roll or creep (which is possible with the brake hold feature).

Mr645

hmm, perhaps consider that the door is closed and locked, driver not likely to exit the vehicle without opening the door first? I could possibly understand the parking brake engage if the drivers door is opened but the seatbelt makes no sense. The parking brake did not release once I re-clipped the seatbelt.

yardie876

Can you imagine someone waiting at a light and taking off their belt to reach something in the rear and accidentally pressing the gas, sending them straight into oncoming traffic? The brake hold function's intent is so you can take your foot off the brake. It's dangerous to use it while doing anything in the driver seat but waiting for the light to turn green.

Mr645

hmm, I really cannot imagine pressing the gas like that. My foot was on the brake as I twisted to reach my wallet. I'm really not enjoying all of the electronic interlocks that supposedly are for safety. I am thinking my Lexus experiment may be a short lived one

dchar

Not sure why you are arguing about how the brake hold system works...I think it works similarly on other makes that offer it. It just makes sense to only allow the feature when the driver has his/her seatbelt on.

Did you step on the brake and then pull the parking brake switch?

coolsaber

The only problem here exists with an unfamiliar driver LOL. jk happens.

But really unless you were unable to dis engage the P brake after putting on your seatbelt, then it should be fine according to the others.

Although Lexus's "feature" seems to be a bit overly cautious, I know plenty of other mfgs that have similar features too. I.E Bimmers have programming that, the minute you put the car in D, and try to creep forward with the door open, it slams the car into Park.

15RC350F

I have just tested the functionality that's the subject of this thread. Here is what I found:

First of all, and as expected, you cannot enable the Brake Hold feature if your seat belt is not fastened. This is obviously a safety interlock which is designed to prevent the use of Brake Hold when you exit the vehicle. You also cannot enable Brake Hold if the driver's door is open (I did not test other doors).

With my seat belt fastened I enabled Brake Hold. I then unfastened my seat belt. A warning appeared on the TFT screen and the parking brake engaged (and Brake Hold disengaged). I was able to disengage the parking brake by depressing the actuator whether or not I put my foot on the brake. Refastening my seat belt in this circumstance made no difference - I was easily able to disengage the parking brake.

By the way, I got exactly the same results if instead of unfastening my seat belt I opened the driver's door: Brake Hold disengaged and the parking brake engaged but could easily be disengaged by simply pressing the actuator.

Mr645

Perhaps there is something I need addressed with my NX. With my seatbelt fastened, the parking brake would not disengage until I turned off the car and restarted it

tresmith00

The hold feature is only supposed to be used for short periods of time like stop and go traffic, waiting in line at the drive thru etc.

and the way that feature works is that you have to reaffirm it every few minutes and that fact makes for a dangerous situation so it requires your seatbelt.

and if you don't have your seatbelt it any engages the parking brake so that in the event you don't or can't reaffirm the hold, your car won't run away with you not having your seatbelt on.

My only issue is that there should be an easier and intuitive way to disengage the parking brake once it comes on.

15RC350F

I suggest that you test the scenario again, as I did, under controlled circumstances, when you are not stressed by blocking a lane of traffic. I am willing to bet that the NX performs exactly like I've outlined above.

15RC350F

There is: you press down on the parking brake control. Couldn't be simpler. Please give it a try next time you're in the vehicle!

legrunt

I can attest to that. In a stressed/unfamiliar setting, many things can go wrong.

One time I had brake hold engaged, waiting at a light. I also had my music really blasting so I didn't hear the warning chime when the timer was almost up and after a while, it engaged the parking brake. When the lights turned green, I just hit the gas and the car obviously didn't move. In a frenzy, I did many many things, wonder what the **** was going on... eventually I calmed down, pressed the brake pedal and pushed in the parking brake button and drove off.

Would really encourage you to try in a stress free environment without impatient people behind honking away.