Question about bz4x ACC

[Audrius1970]

Hi,

Im about to be new bz4x owner from Motability and I failed to find Google answers about Toyota bz4x ACC (Adaptive cruise control) behavior. Maybe current toyota owners can answer me couple questions:

1. After come to full stop in lets say traffic jam, do ACC resume to drive by itself, after car in front starts moving?
In my recent Nissan Leaf after full stop more than 3 sec, systems shutt off and I need to accelerate to 5-7 mph for some amount of time (at least 3-5 sec) and then only system allow me resume after pressing RES button. That is really anoying.

2. Do ACC have option read road speed signs and adapt cruising speed accordingly by itself?

3. Do Toyota ACC keeps braking going steep downhill?
Hope it does, I heard some of other cars ACC failing to do that. I live in hilly city and theres plenty places where is downhill road with speed cameras.

4. What incremental steps ACC button have? My current car +/-1 mph short press, +/-5mph long press.
Some cars doing +/-10mph on long press, I heard MG4 long press +1, short +10 (opposite of others).

Thank you

[philip42h]

All the answers that you are looking for can be found in the bZ4X Owner's Manual (applicable to your car). The manual[s] can be downloaded from the Toyota website: Owner's Information for your vehicle.

1. Similar to your Leaf - after a short stop it will carry on when the car in front moves; after a longer stop it needs to be prompted by touching the accelerator pedal or pressing Resume.
2. There may be but I wouldn't risk using it ... 😉
3. It does a good job stopping you from running into the car in front; it won't necessarily stop from creeping over the set speed going downhill.
4. It varies between models and geographies - you'd need to check the manual. (Mine works in increments of 5 mph).

It is really a "follow the car in front" system and works well on motorway class roads where the traffic is moving reasonably consistently. It doesn't work so well when it can't see or might lose sight of the car in front - so not so good on winding, undulating rural roads. It's not as good as an alert driver because it can't react to the brake lights of the car 'five' in front. It's cruise control after all - it's not a self-driving / autonomous vehicle.

[Audrius1970]

11 minutes ago, philip42h said:

All the answers that you are looking for can be found in the bZ4X Owner's Manual (applicable to your car). The manual[s] can be downloaded from the Toyota website: Owner's Information for your vehicle.

1. Similar to your Leaf - after a short stop it will carry on when the car in front moves; after a longer stop it needs to be prompted by touching the accelerator pedal or pressing Resume.
2. There may be but I wouldn't risk using it ... 😉
3. It does a good job stopping you from running into the car in front; it won't necessarily stop from creeping over the set speed going downhill.
4. It varies between models and geographies - you'd need to check the manual. (Mine works in increments of 5 mph).

It is really a "follow the car in front" system and works well on motorway class roads where the traffic is moving reasonably consistently. It doesn't work so well when it can't see or might lose sight of the car in front - so not so good on winding, undulating rural roads. It's not as good as an alert driver because it can't react to the brake lights of the car 'five' in front. It's cruise control after all - it's not a self-driving / autonomous vehicle.

Thanks for answer.

About traffic stop is good news-on Leaf I cant resume after ACC reset in full stop. Accelerate in traffic to 5mph for prolong time almost impossible so I end up after stop and beep driving manualy for the rest of traffic jam.
About ACC downhill set speed for ex 30 should stay 30 downhill and uphill, even my old Leaf doing that. Just I heard some cars with regen off, failing do sometimes, but tbh sounds like rumors rather than true. Is not like old cruise control from year 2000...
So ACC increments of 5 mph... nice.

Many thx for manual Philip, without magic V... number I was unable to download it.

[Roy124]

Using MY19 Corolla and MY21 YC as a yard stick:

1.  The short stop is not that short but then the EPB will engage.   The effect is to extinguish the brake lights.  It prompts to press the Go pedal.  ACC automatically resumes. 

2.  Definitely not.  It generally recognises speed signs but the signs are often wrong.  Car parks impose limits, they don't cancel them.  Side road limits are often spotted in error, dual carriageway slip roads often get picked up in error. 

3.  Yes.  Typically on a rural road cresting a rise it will overspeed,  warn you, but maintain separation. 

4.  The Corolla default was 5 mph in ACC.  The Yaris defaults to 1 mph.  There is switchology for 1 or 5 mph increments.

[Bilthehut]

26 minutes ago, Audrius1970 said:

Thanks for answer.

About traffic stop is good news-on Leaf I cant resume after ACC reset in full stop. Accelerate in traffic to 5mph for prolong time almost impossible so I end up after stop and beep driving manualy for the rest of traffic jam.
About ACC downhill set speed for ex 30 should stay 30 downhill and uphill, even my old Leaf doing that. Just I heard some cars with regen off, failing do sometimes, but tbh sounds like rumors rather than true. Is not like old cruise control from year 2000...
So ACC increments of 5 mph... nice.

Many thx for manual Philip, without magic V... number I was unable to download it.

Multi-Info Display options allow for choice of 1/5/10 (mph/kph) for short press and same options for a long press.  See page 569

[Audrius1970]

Well, I read the manual

1. ACC in traffic stop: hard to understand, speaking about 3 sec and 3 minutes timeframes.

2. Yup, theres function when with ACC on after reading new speed signs car react, but hard to understand its just suggest to adapt new speed limit sign or do it automaticly. And I know, my old Honda jazz before auto speed limiter keep reading parking 5mpg limits by passing by parking slot lol 😁

3. Cant find about keep speed downhill in manual. Lets hope that car doing what they say-keep speed at set, no matter what. (if there no obtacle or car in front)

4. This car is awesome! According manual, you can set increments in settings, nice.

[Bilthehut]

6 minutes ago, Audrius1970 said:

Well, I read the manual

1. ACC in traffic stop: hard to understand, speaking about 3 sec and 3 minutes timeframes.

2. Yup, theres function when with ACC on after reading new speed signs car react, but hard to understand its just suggest to adapt new speed limit sign or do it automaticly. And I know, my old Honda jazz before auto speed limiter keep reading parking 5mpg limits by passing by parking slot lol 😁

3. Cant find about keep speed downhill in manual. Lets hope that car doing what they say-keep speed at set, no matter what. (if there no obtacle or car in front)

4. This car is awesome! According manual, you can set increments in settings, nice.

Use regen braking button.  This seems to keep speeds down when descending ( certainly works at Fish Hill!)

[Audrius1970]

Reason Im asking, that I love when car is my partner in team, traveling in new unknown places and cities- car watching and obey speed limits, I watching google map.

... till backseat drivers start screaming "you again miss your turn!" 🤣 😅

[ernieb]

Unless the traffic sign recognition system has significantly improved do not rely on it. On my '21 PHEV it has a habit of seeing a restricted speed sign on the motorway but not that the speed limit has cleared. It will often miss temporary speed signs altogether. I nearly always use AA and the speed limits are usually pretty accurate.

[philip42h]

47 minutes ago, ernieb said:

Unless the traffic sign recognition system has significantly improved do not rely on it. On my '21 PHEV it has a habit of seeing a restricted speed sign on the motorway but not that the speed limit has cleared. It will often miss temporary speed signs altogether. I nearly always use AA and the speed limits are usually pretty accurate.

Road Sign Assist is a function of the Toyota Safety Sense (TSS) system. You and I have TSS 2.0

The bZ4X has TSS 3.0 which is four 'generations' later than ours - TSS 2.0, TSS 2.5, TSS 2.5+ and TSS 3.0. So, there have been several opportunities to improve the system!  😉

As you say, it often misses the derestriction sign at the end of a limit, and here in Wales, like the rest of us, it is utterly baffled by the "20 mph" limits - it may not be programmed to measure the distance between the lamp posts correctly! 😄