ACC

[Neil Ives]

I feel this is a serious problem. Has anyone brought it up with Honda?

[Kremmen]

Without proof or recorded scenario they have nothing to go on.

I really thought I had it recorded and pinned but I just can't find it. I reckon because I almost instantly counteracted with the accelerator there was no dip on the dashcam speed even though I felt the deceleration like being in B mode and taking your foot off.

I'll get it, bound to happen again and I know just what to do 

I was on the M4 for about 20 miles and I just can't remember where it was.

[Jazzik]

I really thought I had it recorded and pinned but I just can't find it.
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I was on the M4 for about 20 miles and I just can't remember where it was.

It sounds a bit like a ghost braking...
It happened... it was recorded... it is invisible in the recording... I just can't remember where it was... 

[Hugh R]

You have only to read pages 248-249 to think that the whole system is precarious, to say the least. I have yet to use it and don't particularly want to. The Jazz with ACC is the first car I've had that will automatically slow down, but now I'll be very careful how I use it. That's a pity because standard cruise control has been with us for many years and I am at a loss to understand why Honda lump both together and call it 'ACC with low speed follow' when the 'low speed follow' should have been available independently of CC.  I think this needs to be fixed urgently as not all drivers are as alert as the contributors to this forum.

[guest4871]

You have only to read pages 248-249 to think that the whole system is precarious, to say the least. I have yet to use it and don't particularly want to. The Jazz with ACC is the first car I've had that will automatically slow down, but now I'll be very careful how I use it. That's a pity because standard cruise control has been with us for many years and I am at a loss to understand why Honda lump both together and call it 'ACC with low speed follow' when the 'low speed follow' should have been available independently of CC.  I think this needs to be fixed urgently as not all drivers are as alert as the contributors to this forum.

+1

[Jazzik]

After many hundreds of kilometres/miles of highway I think I have quite mastered driving the car on ACC.
To start with, I almost always set the distance detection to minimum, at high speeds (around 80 mph) sometimes at 2 bars. When overtaking (after indicating of course ): change lanes at a sufficient distance (you learn quickly ...) from the car in front of you.
When you are overtaken and that car moves a short distance in front of you into your lane, nothing happens if its speed is higher than yours.
I haven't experienced any unexpected brake intervention yet, but who knows! I wait patiently.
And indeed, Hugh mentions it: read the manual! Where to use and where better not to use ACC...

[Kremmen]

I've had a few instances, one which I do have on my latest dashcam footage, where I've had to move from lane 1 to 3 to overtake a vehicle in lane 2.

I have my ACC set to 1 bar but even when I think I'm well behind the vehicle in lane 2, when I get into lane 2 the car slows, presumably brakes, and doesn't speed up again until I get into lane 3.

I understand the theory but the range is too big. Also, in my case, on the M4, the speed difference is only 1 or 2mph so it's not as if I'm racing up behind the vehicle ahead.


My ideal would be ACC with an option to set zero bars and that would be the old tried, trusted and tested CC that I've been using for over a decade without issue.

[Neil Ives]

Yes, I've been trying ACC with minimum distance set;  It still slowed me down when I was probably 50m behind the car in front at a distance that urgent speed reduction just was just not required. This was on a country road, not a motorway. I had been travelling at 50mph. Without ACC I would have been happy to take my foot off the gas to allow my car to slow down and match my speed to theirs.

[Expatman]

This is all worrying me! On my present car I use CC a lot, particularly on urban roads to keep to 30 & 40 speed limits. Always plenty of traffic and parked cars by side of road. From what I read here the ACC is unsuitable for use in this environment. Am I right?

[Neil Ives]

This is all worrying me! On my present car I use CC a lot, particularly on urban roads to keep to 30 & 40 speed limits. Always plenty of traffic and parked cars by side of road. From what I read here the ACC is unsuitable for use in this environment. Am I right?

Well, if my poll shows that most people who use ACC are happy with it then the problem may be me but I see that Kremmen also experienced false braking.

I suspect that actually, lots of drivers would not use a simple Cruise Control so ACC may never be an issue for them.

It is a shame that we don't have the option of simple CC on the jazz

[Kremmen]

Here are a few screengrabs from Friday.

In all cases where I mention brakes, I'm not talking severe braking but more deceleration than just easing off in 'D'.

The first 2 are where I break off the M4 at J10 and are in the 60mph average speed zone. My ACC speed is a constant 59mph prior to being auto slowed. The first screenshot is where the ACC has started to slow me down due to the vehicle in front and the second is the distance 'ACC 1 bar' is holding me behind.

IMO far too far away for 1 bar. I dread to think how far back max bars would hold me back :

1) Speed dropped from 59 to 58 = starting to slow down :



2) Speed 51, matching the vehicle in front :



3) As an aside, remember this :



The dash display correctly picks up 50

4) On a positive note, The ACC doesn't always slow you down due to proximity. This Saab muppet was only doing about 1 or 2mph more but his cut in, without indicating, didn't slow me :



5) This one is where I'm overtaking the coach. I'm well behind to safely complete the manoeuvre but the ACC, as seen, has decided to put the brakes on and I've dropped from 49 to 47 before I took over with the accelerator :



6) And finally, I've found the place where I had hardly moved out of lane 3.
Looking at the footage I'd maybe just hit or got close to the white line but I actually changed my mind and stayed in lane 3 to overtake the van, but at this screenshot position the brakes had been applied and I'd only slowed from 49 to 48 before I rapidly took over :

[ColinB]

Interesting pictures! One thing that strikes me is that it’s not clear which of the vehicles the car is responding to, it may not be the one the driver’s attention is on. For example, in (6), there’s a car in lane 3 ahead of you that looks to be about the same distance ahead as the one in pic (1) ... maybe that’s the one causing the braking?

As a side comment, it’s not unusual to see a car ahead on a fast road or motorway that will suddenly flick its brakes on for a few seconds for no apparent reason before continuing normally. I’ve never understood why a driver would do this when simply lifting off the throttle would slow them down if that’s what they want. But maybe they are using ACC (or some marques might use a form of CC that actually brakes the car, unlike the Mk3 Jazz CC which just cuts the gas) and it’s the car that’s done it rather than the driver.

[sportse]

Interesting pictures! One thing that strikes me is that it’s not clear which of the vehicles the car is responding to, it may not be the one the driver’s attention is on. For example, in (6), there’s a car in lane 3 ahead of you that looks to be about the same distance ahead as the one in pic (1) ... maybe that’s the one causing the braking?

As a side comment, it’s not unusual to see a car ahead on a fast road or motorway that will suddenly flick its brakes on for a few seconds for no apparent reason before continuing normally. I’ve never understood why a driver would do this when simply lifting off the throttle would slow them down if that’s what they want. But maybe they are using ACC (or some marques might use a form of CC that actually brakes the car, unlike the Mk3 Jazz CC which just cuts the gas) and it’s the car that’s done it rather than the driver.

In most of my previous cars it was easier/faster to just tap the brakes to disengage the cruise control.

Many cars have it added as an afterthought- on Toyota’s it was a little stalk behind the wheel at the bottom.

[Jazzik]

Here are a few screengrabs from Friday.

---/---

The first 2 are where I break off the M4 at J10 and are in the 60mph average speed zone. My ACC speed is a constant 59mph prior to being auto slowed. The first screenshot is where the ACC has started to slow me down due to the vehicle in front and the second is the distance 'ACC 1 bar' is holding me behind.

IMO far too far away for 1 bar. I dread to think how far back max bars would hold me back :

1) Speed dropped from 59 to 58 = starting to slow down :



2) Speed 51, matching the vehicle in front :

Looking at these 2 pictures I think we have a totally different ACC. Such a distance keeps our Jazz more or less at maximum distance detection!

[Neil Ives]

... In most of my previous cars it was easier/faster to just tap the brakes to disengage the cruise control.

It does the same in the Jazz but the car slammed the brakes on before I could do anything.