I just encounter this "brake hold" bug this past weekend. I have been using brake hold on and off for months and this is the first time that this happened. Here's the scenario.

I went out of town this past weekend. This is the first time that the rdx was parking outside overnight in the cold (around 35F / 1-3C). So I started to drive for the first time that day. I drove for about approx 10 min, then I wanted to check something on my phone, so I pulled over to the side of the road. When I came to a complete stop, the auto start/stop kicked in and turn off the engine. That was the first time it kicked in during that drive. Not wanting to restart the engine (by putting it in park / turning on parking brakes), I turned on brake hold. The "hold" is green, so i let go off my foot.

After 5 - 10 min or so, the engine restarted. However, that caused my brake hold to disengage and my car started to roll forward. Luckily, there wasn't anything in front of me but it did roll forward by 3 feet.

My guess is that the engine temperature wasn't high enough ( or the engine temp dropped while standing still) and restarted the engine. The "warm up" logic in the engine must have added some gas (eg higher rpm) and canceled the hold.
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​​​​​​Beware of brake hold when the engine is not fully warmed yet.

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Forgive my ignorance but why couldn't you put it in Park without turning off the engine..?

 

It is not that I couldn't turn off (completely) the engine. It's that I don't want to restart the engine while the auto start/stop system already stopped the engine.

See https://acurazine.com/forums/third-generation-rdx-2019-454/autostartstop-turns-engine-when-you-shift-park-971979/

 

 

I don't know how long, but I have brake hold longer before during the summer. As far as i remember, the default turn off brake hold behavior should be shift to park instead of rolling forward.

 

 

It was probably close to 5 mins then 10 mins.

Here's page 292 of the manual:

■ The system automatically cancels and the parking brake is applied when:
• Braking is kept for more than 10 minutes.
• The driver’s seat belt is unfastened.
• The engine is turned off.
• Brake Hold System Problem. Apply Brake When Stopped. See Your Dealer. appears on the multi-information display.
• There is a problem with automatic brake hold system

The manual specified which conditions the brake hold will be cancel, but didn't specified which action it would take. However, I can tell you for certain that "driver's seat belt is unfastened" and "engine is turn off" will NOT result in car rolling forward. If you unfasten your seat belt, it will shift to park. Regardless of whether it's 10 minutes or not, if the brake hold function cancels (not due to gas pedal or manually turning it off), it should shift to park instead of rolling forward. That seems dangerous.

 

Just re-read the manual carefully, it states

■ The system automatically cancels *and the parking brake is applied* when:
• Braking is kept for more than 10 minutes.

so, it was something else that cancelled the brake hold and cause the car to roll forward. I suspect, it's the engine restart due to Auto start/stop conditions.

 

 

Thanks for the warning. This will cost someone some $$ at some point.

I've messed with brake hold a little here and there, but I must be missing something. I don't get what the point is. Holding the brake is no effort and putting a vehicle in park is even less. Not trying to be sarcastic. I just don't get it. Anyone have a good practical example of it's use.

 

I had a similar thing happen to me the other day. I was using brake hold in an area with a lot of stop lights. I stopped at a red light, the engine shut off and the brake hold engaged. Within seconds, the engine restarted and the brake released just as a pedestrian was crossing in front of me. Fortunately I reacted in time, but it was a scare.

 

 

For those who experienced the same problem, was your engine still warming up?

I used the brake hold feature a lot during warmer climates, it never happened to me.

 

 

I had a 2015 TLX and used brake hold every day. I never once had the brake hold release when the engine restarted. I have had it happen twice in the past week in my RDX. This is definitely not normal. I will mention it to my dealer when I go in for my first service.

I think that both times when it happened I had pressed the Auto Start/Stop button to restart the engine. I'll pay attention from now on to see if it happens when I wiggle the steering wheel or only when I press the button.

 

Instead of putting it in park and then turning on the parking brake, just turn the car off. The car goes automatically to park and then you can turn the parking brake on. In fact, I normally put the parking brake on and then turn the car off. I don't know that I have ever hit the park button.

Billy

 

 

Next time, just hit the ignition button. Problem solved.

 

I don't get this dismissive altitude. The main point of this thread is not to complain about the car. It's to warn other owners of this buggy feature, so that they won't crash into something or god forbid, someone.

​​​​​​It's perfectly reaonable to use brake hold in short stop scenario (such as drive thru and red lights). And I would argue that this feature is actually designed for it.
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For you to say "Next time, just hit the ignition button. Problem solved." -- it's like me saying just turn your head and look thru the rear window when you are saying that the rear view camera is not working.

 

Billy, the point here is to keep the car ON (eg. Climate control , seat warmers etc) for a temporary stop.

Not sure if you know this, you can even set the car to turn on parking brakes automatically after ignition have been turn off. You don't need to do it manually. Look in the manual or other threads in the forums for instructions.

 

I apologize if I missed the point. I do know that you can make the parking brake come on automatically. The point of your initial post I focused on (which was obviously very wrong) was that you didn't want the engine to start again, nothing was said about keeping the climate control on.

Billy

 

I've had this happen to me a few times. This seems like a potentially serious issue.