Jump to content
Do Not Sell My Personal Information


Active Cruise Control & Indicators Question


Rambler56
 Share

Recommended Posts

I use the active cruise control a lot and thought I had mastered all it's nuances but now not sure I have.  

When following a car slowing down to turn left when the radar is locked on it's easy to either sit back a bit to stop the car braking too much or touching the accelerator to avoid the braking effect.  

On the motorway I'm happy to let the ACC do it's thing and keep me a reasonable distance behind the car in front.  

When catching slower vehicles I've noticed that if the car slows due to being locked on to the car in front that if I indicate without touching the accelerator the car speeds up without my input.  Am I dreaming this (I tried it several times and it accelerated each time)?  I haven't spotted anything about it in the manual and nothing came up when searching this forum.  

Are there any more undocumented ACC 'tricks'?

  • Like 1
Link to comment
Share on other sites

26 minutes ago, Rambler56 said:

I use the active cruise control a lot and thought I had mastered all it's nuances but now not sure I have.  

When following a car slowing down to turn left when the radar is locked on it's easy to either sit back a bit to stop the car braking too much or touching the accelerator to avoid the braking effect.  

On the motorway I'm happy to let the ACC do it's thing and keep me a reasonable distance behind the car in front.  

When catching slower vehicles I've noticed that if the car slows due to being locked on to the car in front that if I indicate without touching the accelerator the car speeds up without my input.  Am I dreaming this (I tried it several times and it accelerated each time)?  I haven't spotted anything about it in the manual and nothing came up when searching this forum.  

Are there any more undocumented ACC 'tricks'?

If you have the ACC active and are following a vehicle the system will try to maintain a set distance, reducing speed if necessary however if you pull out to overtake indicating as you do so then the car will accelerate to the set speed provided there are no slower vehicles in the 'overtaking' lane. This may not be ideal under all circumstances as if there are vehicles behind travelling faster then they can be baulked by you as the rate of acceleration in ACC is relatively slow. Best to override and accelerate manually if this is likely to occur.

  • Like 1
Link to comment
Share on other sites

Yup, notice this as well. If you start indicating the car accelerates.

  • Like 3
Link to comment
Share on other sites

9 minutes ago, Bozz said:

If you have the ACC active and are following a vehicle the system will try to maintain a set distance, reducing speed if necessary however if you pull out to overtake indicating as you do so then the car will accelerate to the set speed provided there are no slower vehicles in the 'overtaking' lane. This may not be ideal under all circumstances as if there are vehicles behind travelling faster then they can be baulked by you as the rate of acceleration in ACC is relatively slow. Best to override and accelerate manually if this is likely to occur.

I fully understand what the ACC is doing when the radar locks onto the car in front and the rather sedate acceleration back up to speed when you do change lanes but I'm talking about when you do not pull out and just put your indicator on (with no steering input to change lane) the car appears to speed up.

  • Like 1
Link to comment
Share on other sites

1 minute ago, AndrueC said:

Yup, notice this as well. If you start indicating the car accelerates.

I doesn't cancel the ACC as when I do pull out it carries on as normal and accelerates up to the speed setting.

  • Like 2
Link to comment
Share on other sites


25 minutes ago, Rambler56 said:

I fully understand what the ACC is doing when the radar locks onto the car in front and the rather sedate acceleration back up to speed when you do change lanes but I'm talking about when you do not pull out and just put your indicator on (with no steering input to change lane) the car appears to speed up.

Yes the ACC is antcipating that you are going to overtake when you activate the indicators

  • Like 2
Link to comment
Share on other sites

Maybe a tweak to the software by Toyota is required?

Maybe as the system checks the radar & camera inputs, it could also check the steering angle sensor to see if the driver is truly pulling out to overtake.

 

 

Link to comment
Share on other sites

As the car is programmed to avoid crashing it will first warn and then override your implicit instruction to accelerate. 

Adding a steering sensor could be an additional complication. 

To illustrate my first point, I was following a car out of a car park.  I was still accelerating when he suddenly stopped. A flashing red caption appeared warning me and a moment later it applied the brakes. I overrode the automatics as I applied brake too. 

  

Link to comment
Share on other sites

I think the point some are missing here is the OP's observation that activating the indicators without any other control input is enough to cause the car to accelerate toward the target speed. The car will do this even though the immediate result is to reduce the gap to the vehicle in front below that configured in the ACC settings.

Presumably if the driver doesn't steer the car there will come a point where the ACC decides to back off again.

  • Like 5
Link to comment
Share on other sites

1 hour ago, Roy124 said:

Adding a steering sensor could be an additional complication. 

  

There is already a perfectly good steering angle sensor installed behind the steering wheel as part of the ESP system.

  • Like 2
Link to comment
Share on other sites

5 hours ago, AndrueC said:

Yup, notice this as well. If you start indicating the car accelerates.

Yep, mine too.

Surprised me the first time it happened, but I'm used to it now.

  • Like 2
Link to comment
Share on other sites

My Corolla will be our 4th car with ACC.  Both my previous Kia Niro and my current Skoda Octavia do the same.  The wife's Yaris also does it.

Link to comment
Share on other sites

That happened to me too. ACC on, wanting to overtake on the motorway(say someone doing 65 in a 70), so i have signalled to go out but a car was going way faster on the fast lane so i changed my mind(indicating but no steering input) andthe car started to accelerate at the set speed(70) with the car in front of me.

Link to comment
Share on other sites

Following on from PRus, 

In the following scenario, ACC set at 65, following a truck so the speed has dropped to 60.

Cars approach on your right.  As the car starts to overtake you indicate to join the overtaking queue. 

Once you indicate your car accelerates and 'races' the overtaking car rather than easing on behind. 

Something you need to be aware of. 

  • Like 1
Link to comment
Share on other sites


I usually cancel the ACC if I'm going to take over control for a manoeuvre, e.g. if the car in front is slowing or if I want to perform an overtake, as I have grown to dislike the slight unpredictability when two things (i.e. me and the ACC) are trying to control the car at once!

 

  • Like 3
Link to comment
Share on other sites

16 hours ago, Cyker said:

I usually cancel the ACC if I'm going to take over control for a manoeuvre, e.g. if the car in front is slowing or if I want to perform an overtake, as I have grown to dislike the slight unpredictability when two things (i.e. me and the ACC) are trying to control the car at once!

 

 

20 hours ago, Roy124 said:

Following on from PRus, 

In the following scenario, ACC set at 65, following a truck so the speed has dropped to 60.

Cars approach on your right.  As the car starts to overtake you indicate to join the overtaking queue. 

Once you indicate your car accelerates and 'races' the overtaking car rather than easing on behind. 

Something you need to be aware of. 

To both of you, I just indicate when there is a gap to go into, and all is fine.  In fairness I have had ACC with the same 'feature' since 2017 and done most of the 60000 miles the cars have done on the motorway, so I have grown used to it. I find it intuitive as it is what I would naturally do.

Link to comment
Share on other sites

Its other quwerk is slowing down when the vehicle ahead slows (as it is supposed to) prior to turning off. Once the other vehicle has turned off or moved into a slip the ACC continues to cause the car to brake. 

A car following will not expect you to slow down when the road ahead is clear. 

This is one occasion where you might use the indicators to fool the ACC. 

As the car ahead starts to slow down a car following you might expect you to pull out.  As the car ahead starts to clear, indicate right, maintain speed but don't move out 😁

  • Like 1
Link to comment
Share on other sites

Yeah, that's another situation I cancel the ACC and take over, so it doesn't slam on the anchors thinking the other car has stopped, and then just resume it afterwards.

Link to comment
Share on other sites

I think, first week, not only did it slow down but lane followed the preceding truck into a filling station. 

  • Like 1
Link to comment
Share on other sites

Haha, yea, if it locks onto a vehicle instead of the lane (i.e. 3 dots instead of blue side-bars) that can happen! :laugh: 

Link to comment
Share on other sites

The indicators are linked as already said in other replies... Same for the Lane Guidance Assist too - if you do not indicate it will alarm that you are deviating over the lines, but if you indicate the systems goes into standby until you get into lane.

Have only tried the Adaptive Cruise a few times to see what it's like - but probably will only ever use Constant Cruise as this allows for 1mph increments instead of 5mph increments (which for adaptive is bad in my opinion).

Plus as all newer cars speedos are set about 2mph more than actual you feel like everyone is coming up behind you and then overtaking.

Link to comment
Share on other sites

Tech, only 2 mph, lucky you.  I have a GPS speed cam monitor.  My speedo is 10 % out.  I need to set 75 to cruise near 70 and 65 to go co-speed with trucks. 

27 in a 30 zone is fine though it does seem to surprise/annoy other car drivers who think 35 is acceptable. 

  • Like 1
Link to comment
Share on other sites

14 minutes ago, Roy124 said:

Tech, only 2 mph, lucky you.  I have a GPS speed cam monitor.  My speedo is 10 % out.  I need to set 75 to cruise near 70 and 65 to go co-speed with trucks. 

27 in a 30 zone is fine though it does seem to surprise/annoy other car drivers who think 35 is acceptable. 

Yes I have my Tom Tom fitted in place too... and it shows 2 to 3 mph less than that.  Yes acceptable in a 30, but out on the bypass or motorway the ACC is a pain to maintain.

Link to comment
Share on other sites

What you can do it manually accelerate to you chosen true speed, then select ACC.  If they vehicle ahead slows down for traffic say then let ACC do its thing. 

If the vehicle just slows down indicate whdn safe and resume your original speed. That's the way to do it, as Mrs Judy would say. 

  • Like 2
Link to comment
Share on other sites

never noticed this but i only tend to use acc when in spec camera zones through roadworks or on so called smart motorways. 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share





×
×
  • Create New...




Forums


News


Membership