Front assist problems please help

[prokaryotic]

Since last two months I had yellow front assist sign on dashboard with an exclamation mark, hence could not activate Adaptive Cruise control and Traffic Jam assist, last week I drove around switching it off and switching it on several times, eventually it got activated seems to behaving itself so far. Any suggestions what could be the problem? Should I take it to dealer still got 3 months warranty left?

[Kenny R]

The only times the front assist warning has came up on my car are when the radar sensor has been covered in snow ice, and once when a wet leaf managed to stick to sensor.

I believe if the radar unit gets very dirty it has the same effect.

[FlyingGecko]

If it's clean like Kenny R says, get round to the dealer ASAP.  If it's something simple, just plead ignorance and take the embarrassment - it could be something costly.  Three months is three months.

[prokaryotic]

whereabout radar sensor is located? forgive my ignorance

[CJJE]

Behind the central 'blank' area in the middle of the black plastic grill I believe. (Which is why the Skoda badge is mounted up on the bonnet and not in the middle of the grill as they used to be.)

 

Chris

[FlyingGecko]

As CJJE says.  So it's well protected from the elements.

[Teds]

Not much help with this enquiry but the ACC will not engage if the space saver tyre is on. (I tried it but fortunately all returned to normal when the normal tyre was replaced.) This may also occur if the pressure in the two front tyres is significantly different but that is guess rather than known for sure.

[FlyingGecko]

Teds, I accept what you say is true, but,  WHAT???

[Teds]

I found out the hard way. I had a puncture about 20 miles from home.  The spacesaver was put on and I had about 15miles of dual carriageway to travel. Set the ACC for 50 and potter along but it would not engage. I was concerned that it was a fault but once the normal tyres were on, the ACC worked normally.  I was told that it is something to do with the system measuring the revolutions of the front wheels. With a space saver (and possibly a large pressure difference with between normal tyres), there is a consistent difference in the revolutions between the two front wheels which spooks the system. 

[DSL]

I had a look at my skinny spare compared with my normal 225/55/17 tyre, there was about a 7% reduction in rolling circumference, hence car would think the hub with the spare on was going 7% faster.  That might be enough for the car to throw a minor wobbly and not engage ACC. 

[FlyingGecko]

Teds, DSL -  fair enough. Obviously Skoda's cruise control is a lot smarter than my old Saab's was!  Thanks - I'll try to remember this if I ever need to put my spacesaver on.

[DSL]

Daft thing is there is an Audi space saver (from memory) that has virtually the correct rolling circumference, hence would be perfect, but that’s not what we get.  I was going to source one but went for a 5th full sized alloy with identical tyre.  For both summers and winters.  You can never have enough wheel & tyres!  

[prokaryotic]

Thanks guys for your replies, all this makes lot of sense to me now! , My front assist problems started after I had a tyre blow out on a pothole! Hopefully problem is resolved.

[Phil245]

On 23/03/2021 at 16:24, Kenny R said:

The only times the front assist warning has came up on my car are when the radar sensor has been covered in snow ice, and once when a wet leaf managed to stick to sensor.

I believe if the radar unit gets very dirty it has the same effect.

 

Yes I set off for work one snowy morning and fussed and fretted all day wondering what the orange warning light was and whether I could get an appointment at the dealers with covid being around to get it looked at.  By home time the snow had slid off and all systems go ! Wasted a day worrying about it though!

 

It has happened a couple of times since  driving during heavy snow, I have even stopped en-route to clear the built up snow...!

[Ootohere]

Common advice is that Cruise Control should not be used in adverse weather, flooding roads, ice,snow etc.   Then as for ACC or CC being disabled / inhibited when a spare tyre is on, or a different circumference tyre, that is a design feature not a car throwing a flaky.    As it is using CC when a emergency spare is fitted is hardly Simply Clever. 

Edited 28 March, 2021 by e-Roottoot

[JohnD5314]

Re ACC - I wonder if it is anything to do with the fact that there is a 50 mph speed limit with the space saver? Maybe Skoda think more driver attention to speed is required and they might not reduce the CC set speed (I have to be honest, I am not really convinced by that argument but I thought I would put it out there).

 

Re radar - I have had the warning that is was not operational a couple of times, both associated with very heavy rainfall which I imagine could affect the radar. All cleared when the rain relented.

[FlyingGecko]

58 minutes ago, JohnD5314 said:

Re ACC - I wonder if it is anything to do with the fact that there is a 50 mph speed limit with the space saver? 

 

 

Doesn't apply to Audis.  At least not the A4 doing over 80 that passed me on the M53 a while back.   Sometimes, you just want them to crash.

[Phil245]

19 minutes ago, FlyingGecko said:

Doesn't apply to Audis.

 

Ah yes.......but speed limits in general don't apply to Audi's ( or BMW's).....