Cruise control braking - brake lights?

[juux]

Apologies for the question, bit of an odd one but I'm not sure how I'd test this without asking Mrs Juux to follow me in her car...!

I've had cars with cruise control before, but none that actually brake to keep you within a certain tolerance of your set speed.

You can feel the car brake gently on downhill stretches, but does it actually display the brake lights aswell?

Or is the fact the car is maintaining a speed within a small range mean it doesn't do this, the thinking being that cars behind won't need the signal as braking is never sharp?

 

[Dieselman]

Are you sure the brakes are being applied, not just the engine fuel being cut?

 

[flango]

Not sure with MB but Volvo and BMW both use the brakes when in cruise and do not display the brake lights.

 

[developer]

If it has Distronic (which keeps you at a set distance from the vehicle in front, amongst other things) you will have needed to activate it yourself.

It's not cruise control, as such.

I don't believe it activates brake lights, which might seem a bit dangerous, but as it's used on the motorway mainly, it would be as dangerous to keep having brake lights activating, as it continually self adjusts to traffic conditions.

 

[Benzowner]

I am sure this has been discussed before, cruise control mainains speed so, technically, you are not slowing down so the brake lights shouldn't have to work. However, I am sure the "braking" feeling is engine braking.

 

[G.P]

Not sure with MB but Volvo and BMW both use the brakes when in cruise and do not display the brake lights.

My BMW does not use the brake's. .

 

[donubenz]

My SL has the radar distronic cruise and it definitely does put the brake lights on as I as seen it reflected in the following car at night. To be honest I would be worried if it did not as some times if the car you are following brakes hard and the cruise picks it up you need to warn the following car due to the response.

 

[developer]

My SL has the radar distronic cruise and it definitely does put the brake lights on as I as seen it reflected in the following car at night. To be honest I would be worried if it did not as some times if the car you are following brakes hard and the cruise picks it up you need to warn the following car due to the response.

Now you have me thinking .

 

[corned]

As posted a few times before, my 211 (2005 vintage, not distronic) uses the brakes to control speed in cruise, and in this case the lights DO come on.

 

[flango]

My BMW does not use the brake's. .

My Nephews 530d M Sport E60 definitely does, states it in the manual and I followed him to check the brake light theory thats how I know

Volvo not only applies the brake in cruise, it apply them when discs are wet as well to optimise braking

 

[flango]

Distronic is different, cars with active cruise and radar measurement do use the brakes and do bring on the brake lights. Cars I know (BMW& Volvo) that use active braking as part of normal cruise control do not bring on the brake lights. However as posted by corned MB use braking in normal cruise and it would appear they DO bring on the brake lights

 

[C43AMG]

I have Distonic + on the S-Class and Distronic on the CL and on both the brake lights come on, as mentioned it would be very dangerous if they didn't.

 

[developer]

I have Distonic + on the S-Class and Distronic on the CL and on both the brake lights come on, as mentioned it would be very dangerous if they didn't.

I would certainly expect D+ to put the brake lights on as it brings you to a stop.

I wonder of they are activated by the severity of the braking, i.e under hard braking, and don't come on under more gentle speed adjustments on the motorway .

 

[st13phil]

The standard cruise control (i.e. not Distronic Plus) fitted to the W204 and W212 activates the brakes to stop overspeeding, but does not activate the brake lights when it does so. This isn't an issue in normal use as the brakes are only being used relatively gently, but the car will apply them quite firmly if, for example, you are travelling at 40-50mph and reactivate cruise when the last set speed was, say, 30mph.

 

[juux]

Are you sure the brakes are being applied, not just the engine fuel being cut?

No, car is an auto and engine braking is negligible - this definitely feels like 'proper' braking, albeit light.

Car doesn't have Distronic either.

I guess from other responses that the lights don't go on; this pleases me as I'd prefer not to have my lights flicking on and off going downhill on cruise.

Thanks

 

[juux]

The standard cruise control (i.e. not Distronic Plus) fitted to the W204 and W212 activates the brakes to stop overspeeding, but does not activate the brake lights when it does so. This isn't an issue in normal use as the brakes are only being used relatively gently, but the car will apply them quite firmly if, for example, you are travelling at 40-50mph and reactivate cruise when the last set speed was, say, 30mph.

Yeah, done that once - quite off-putting! Guess I'll learn to live with that 'quirk'.

 

[GordonTarling]

On my 211, the brakes definitely came on when vehicle speed exceeded set speed. Brake light reflections also confirmed that. On my previous 210, I'm fairly certain that the brakes didn't come on with cruise. Sorry, don't know about other models!

 

[Bosco]

Great question OP. Now all we have to do is figure out what makes the magic blinking lights at the corner of most vehicles flash from time to time.

 

[corned]

Great question OP. Now all we have to do is figure out what makes the magic blinking lights at the corner of most vehicles flash from time to time.

Now, Bosco. There are some things that man is not meant to know...

 

[juux]

Now, Bosco. There are some things that Audi-driving man is not meant to know...

Fixed that for you