Cruise Control Unwanted Behaviour

[fred_jb]

Trouble is I can't be absolutely sure it is a fault. Almost impossible to replicate.

In fact I seldom use CC. Compared to a car a bike needs frequent fine throttle inputs and adjustments. Also UK roads are seldom free enough of traffic. Most often use it when my right hand and arm need a rest.

I tend to feel the same and rarely use it, even in the car, as I like to use the throttle to reduce or increase speed slightly to time lane changes on multi-lane roads to fit in with other traffic, and I find CC just too frustrating on anything except almost empty roads. For example, with CC on you can end up approaching a slower car at a fixed rate such that something coming up behind in the overtaking lane causes you to have to brake to wait for it to pass, rather than just slowing a little as you would with manual control.

I only used it recently in France on the bike partly just to try it out, and also because I was on some fairly deserted roads rural roads where I didn't want to exceed the speed limit by too much.

 

[fred_jb]

Yep ! Thx Fred , similar expectations here.
Stopping 3 m quicker in the wet from 60 could be a life saver one day?

Yes - that's my thinking too. Hope you get your tyre situation resolved soon.

 

[XPilot]

Tried the RESUME function this morning. Set CC at 100km/h (I'm in Austria/Germany) in 5th and disengaged via clutch. Exited a roundabout at 25km/h in 2nd and selected RESUME. A very gentle acceleration ensued as the CC took over. Not harsh in the slightest so I very much doubt it woiod cause any issues whatsoever if accidentally selected.

 

[Sea Dog]

In fact I seldom use CC. .

I tend to feel the same and rarely use it, even in the car,

I think this is where the true issue lies, not just for you guys but for many and in cars s well as on bikes. The Resume function is meant to do exactly that - resume the previously set speed, car or bike. Frankly, cruise would be very much the poorer for not doing that. The fact is that (provided you are above 20mph or it won't cut in) pressing resume can demand acceleration, and this is clearly laid out in the manual. Some folk just don't 'get' cruise, others do. If you've got iffy gloves or somehow manage to pull the switch towards you inadvertently, you need to look at what you're doing or leave the thing properly off. Of course, the merest dab of clutch will immediately cut the unwanted power, so the habit of covering the lever with a finger or two works here too. I'm not seeking to have a pop here, I simply don't see any design flaw.

 

[Deleted account 200123001]

Anyway, I would interested to hear if anyone else has had problems with accidental activation of CC, and what your views are on whether BMW should have programmed it to be inoperable below a certain speed, or to at least be more gradual in its throttle application from slow speeds.

Fred

It is inoperable below about 20 mph I think...

 

[matchbox]

I think this problem, if there is one, is specific to '17 MY bikes. As stated before, same controls as 15' MY, same riding position, same bars, same gloves. Maybe it's new bike, older rider syndrome?

 

[fred_jb]

It is inoperable below about 20 mph I think...

I was definitely going at less than 20 mph, probably less than 10 mph, and was in 1st gear when I tried resuming it yesterday, and it resumed with a bit of a jolt. In fact I was really not expecting it to resume at such a low speed, so it gave me a bit of a shock and I instinctively pulled the clutch. Maybe because I wasn't expecting it it seemed a more harsh acceleration than it really was, so I will have to try it again sometime to make a proper judgement.

I am not too impressed that a deliberate resume is allowed at low speed and low gears. I really think resume should be locked out until you are above a certain speed/gear or maybe are within say 20 mph of the set speed. For example if you are in 1st gear, without rider intervention, is it going to keep accelerating until you hit the rev limiter? I just don't think it is a good thing for the bike to be on autopilot while accelerating from low speed up to cruising speed, and I can't envisage any circumstances where I would want that.

However, what I am most concerned about is that from anecdotal evidence there is a possibility that 2017 MY bikes are randomly self activating the resume function, which if true I think is downright dangerous. The original incident I experienced (in the video clip below) could be entirely or mainly pilot error, but if there is any chance that it was even contributed to by the CC resume kicking in, then I think it illustrates the potential consequences.

 

[Deleted account 200123001]

I was definitely going at less than 20 mph, probably less than 10 mph,

I'll try the resume function at low speed tonight on the way home and see if it will resume at less than 20.....maybe you've found a flaw fred.
The resume can be quite brisk, it would certainly make sense.

 

[fred_jb]

Tried the RESUME function this morning. Set CC at 100km/h (I'm in Austria/Germany) in 5th and disengaged via clutch. Exited a roundabout at 25km/h in 2nd and selected RESUME. A very gentle acceleration ensued as the CC took over. Not harsh in the slightest so I very much doubt it woiod cause any issues whatsoever if accidentally selected.

What riding mode were you in? Possibly Dynamic mode which I had selected might accelerate more harshly.

 

[XPilot]

I was in DYNAMIC Fred.

 

[fred_jb]

I was in DYNAMIC Fred.

OK - that's interesting, and many thanks for trying it out. However there could be a difference between engaging at 25 km/h in 2nd, and at walking pace in 1st - if not in actual acceleration, then in perceived acceleration relative to current speed. I'm going to have to test this again, and maybe save the video of it to review afterwards.

Fred

 

[XPilot]

Surprisingly when I tried engaging the CC at 10mph in 1st, in DYN, it engaged !

 

[Deleted account Aberdeen GS]

Surprisingly when I tried engaging the CC at 10mph in 1st, in DYN, it engaged !

Fred will be reassured to read that discovery. Odd/surprising that it works that way though?

 

[fred_jb]

Surprisingly when I tried engaging the CC at 10mph in 1st, in DYN, it engaged !

Was that engaging as in setting, or engaging as in resuming? According to the manual you can only set it in the range of 20 km/h - 210 km/h. The manual doesn't specify what speed it will resume at, having previously been set within the allowable range, but it's looking like it will resume at any speed. Not good in my opinion, especially if there is the slightest chance that it will resume without being asked to!

 

[Deleted account 200123001]

The resume doesn't work below about 20mph tried it a few times. I still think it was the hydraulic clutch playing up.

 

[XPilot]

Fred, that was setting the CC - ie pushing the switch forward.

 

[fred_jb]

Surprisingly when I tried engaging the CC at 10mph in 1st, in DYN, it engaged !

Fred, that was setting the CC - ie pushing the switch forward.

So that's contrary to what the manual says as 10 mph is not equivalent to 20 km/h, so you shouldn't have been able to do that. If this is not the case on pre-2017 bikes, then it is starting to look like there is something not quite right with CC on the latest version.

Fred

 

[matchbox]

Had another anomaly with cruise control today.
Master switch was in the 'on' position but had not used cruise for a couple of days. I had just joined M5 and riding at a steady speed until moving over to join faster traffic when the bike started to accelerate(no input from me). Realised what was happening and a quick dab of the brakes restored control.
Now really concerned there is a fault with the system. Having not used cruise today and had several restarts(which cancel cruise memory) I cannot see how this could happen. My '15 GS had exactly the same switch gear and operation and never produced this fault(same gloves aswell) and I never had master switch in the off position.
I intend to raise this with my dealer who will say they've never heard of this problem and of course diagnostics will show nothing. I hope to get them to raise issue with BMW. In my opinion it is a serious and dangerous fault.
Best leave switch in 'off' for now.

Apart from fred_jb, has anyone else had this experience?

 

[fred_jb]

Had another anomaly with cruise control today.
Master switch was in the 'on' position but had not used cruise for a couple of days. I had just joined M5 and riding at a steady speed until moving over to join faster traffic when the bike started to accelerate(no input from me). Realised what was happening and a quick dab of the brakes restored control.
Now really concerned there is a fault with the system. Having not used cruise today and had several restarts(which cancel cruise memory) I cannot see how this could happen. My '15 GS had exactly the same switch gear and operation and never produced this fault(same gloves aswell) and I never had master switch in the off position.
I intend to raise this with my dealer who will say they've never heard of this problem and of course diagnostics will show nothing. I hope to get them to raise issue with BMW. In my opinion it is a serious and dangerous fault.
Best leave switch in 'off' for now.

Apart from fred_jb, has anyone else had this experience?

That is rather worrying, and I agree that it is both serious and dangerous. I'm off touring for nearly four weeks at the beginning of August, so I am a bit concerned about this happening to me again as I still think it is the most likely cause of my "incident". I just hope it can't happen with cruise in the off position. I'm intending to leave mine off for the whole trip as I know if I use it at all I am bound to forget to put it back in the off position. If I had a similar incident to the one in Brittanny with luggage and my wife on the back I might not be able to avoid a crash.

The bike is booked into the dealer on the the 26th to have the fork fix fitted before I leave, so I will definitely mention this to them and ask them to pass on the information to BMW.

 

[fred_jb]

I wonder if it is a software issue, or just a physical problem with the contacts in the set/resume switch randomly shorting - maybe in response to vibration? In that case it might still happen with CC in the off position if the on/off switch is simply a mechanical interlock to stop the set/resume from moving, and has no electrical input of its own to disable the whole system.