Scary incident on the motorway today.

[Jeremy]

Something worrying happened to my REx as I was driving along the M4 into low sun today.

I usually use the interactive cruise control on motorways - and it has occasionally dropped out with a loud warning tone. Usually. I just reactivate it with the steering wheel buttons and continue without problem.

Today, maybe because of the low, bright sun, it dropped out repeatedly each time I tried to reset it - finally giving a message on he driver display saying something like "interactive cruse control cannot be activated" as well as a warning message on the main screen.

By coincidence, this happened when I had run the battery down to about 5 miles and was about to engage the REx to get home. When I pressed my "favourite" button to engage the REx, nothing happened - even with multiple presses. I then realised my range was down to 3 miles, it was further than that to the next junction, and I was going to be stranded if I couldn't start the REX engine.

Although I was in heavy, fast traffic - I decided I would have to pull onto the hard shoulder and try and sort things out. I then switched off and restarted a couple of times - but the main screen fault display still kept returning.

I realised then that the fault display had an "OK" option in the list which i could scroll down to and accept - after which the fault display cleared and the navigation screen returned. I was then able to drive away normally and the REx activated as usual.

Looking back - I think I stupidly didn't notice the fault display "OK" option and could have cleared the fault and continued without stopping - but I really think this is an unacceptable ergonomic issue. A fault on an optional function like cruse control shouldn't cause the loss a main driving function like engaging REx power. Also, in my opinion, no condition which arises unexpectedly while driving should distract you by forcing you to use the iDrive menu system to continue safely.

I also don't understand why the failure of the interactive cruise control required a menu reset this time when it hasn't previously.

Has anyone else had similar experiences?

 

[philcro]

My active cruise control has always acted like this with a notice on the main screen requiring a press on the Idrive. The REX problem I have not had but it did kick in automatically when I got to a 3 mile electric range, are you sure the REX was not running as mine seems to stop when I stop.

 

[jadnashuanh]

When you're having problems with the ACC, you can disable that function and return it to a 'normal' cruise control by pressing and holding either of the following distance buttons on the steering wheel. The bright light and extreme shadows in that sort of lighting situation can make the camera's picture unreliable, which is why it shut off - it cannot reliably recognize things.

 

[Jeremy]

phi/jad

I understand that low sun can wipe out the camera and that it gives a fault display on the main screen as well as a warning tone.

My recollection is that previously I have been able to reset it with the wheel buttons - without having to resort to the iDrive menu.

In any case, I'm quite happy to just continue driving manually when the camera fails - but I don't think having an unacknowledged alert on the iDrive screen should disable other vital driving functions assigned to "favourite" buttons.

It seems a bad control philosophy to allow interruption of an unstable ancillary function like ICC to interfere with essential driving functions.

The REx definitely wouldn't accept the start signal - because the petrol range bars remained greyed out. When it starts - they brighten up.

 

[Jeremy]

Yesterday I confirmed the usual operating sequence when the ICC cut out again in low sun.

You can restart it with the RES button on the steering wheel and the main screen warning display disappears after around 10 seconds without having any effect on other driving functions.

I still don't understand the permanent fault condition that I got the other day after multiple reset attempts though.