SBC Brake hold query

[MD5]

Yesterday, I started the car after a local journey, pulled out of a side street into crawling traffic and realised the SBC/Brake Hold function had engaged itself, something I rarely use, unless I had inadvertently done so on this occasion. The brakes were only applied lightly, bringing the car, an 04 E500 estate, to a gradual halt each time in the stop/start traffic. About half a mile on I was able to pull over and restart the car, which released the function after other normal attempts had failed (stop/start braking). The car was fine from then on.

I'm wondering whether or not this is an early onset symptom of something about to happen that may need attention, or just a glitch of some sort? The car had a new SBC pump fitted about 6 years/50k ago, mostly motorway mileage since.

Any thoughts please?

 

[whitenemesis]

It may never do it again, just ignore it. Certainly not a sign of impending failure.

If anything I'd suspect the brake lamp switch above the pedal...

 

[b1g1an]

You accidently turned SBC Stop on, activated by nudging the cruise lever I believe.

Was only available on early SBC equipped cars and supposedly removed as it was confusing to drivers

 

[MD5]

You accidently turned SBC Stop on, activated by nudging the cruise lever I believe.

Was only available on early SBC equipped cars and supposedly removed as it was confusing to drivers

QED, Ian! Thanks for that, it belongs in the things you've learned about your car thread. I've had it nearly five years and that's a first!

 

[jdrrco]

Whilst glad that I still have "Hold" on the CLS, I do miss the "Stop" function. It was very useful for one-foot driving in towns/cities.

I never saw why it should be considered confusing. Once you know it's there, it's really very simple to utilise.

 

[b1g1an]

QED, Ian! Thanks for that, it belongs in the things you've learned about your car thread. I've had it nearly five years and that's a first!

I went for the opposite, spent ages trying to activate it before I found out it wasn't there

 

[MD5]

I went for the opposite, spent ages trying to activate it before I found out it wasn't there

I'll bet I couldn't do it again if tried - I've no idea how it happened!

 

[mersum1es]

I'll bet I couldn't do it again if tried - I've no idea how it happened!

At low speed (<15km/h?) 'resume' cruise control... you can also disengage it from cruise stalk (or it should disable itself when speed goes over 45 or something...

Its a bit weird you have it, like said above they disabled whole feature in SBC system when software was updated (or unit changed).

 

[MD5]

Thanks for the tip, mersum1es. I'll consciously try it to make sure, but at the time, I wasn't sure if the brakes were binding as I wasn't expecting them to come on, even though they weren't firmly applied, and I doubt I'd use it again.

I don't know why it wouldn't have been deleted when the SBC pump was replaced, unless the previous owner was consulted first or it is standard on the 500, I wonder?

 

[MD5]

Yep, it's a fully fledged function, working as it should.

 

[Kevlaar]

Am I right in thinking the purpose of the "SBC Hold/Stop" function was to allow the car to slow itself down/stop the car at low speeds, as jdrrco said, for stop-start town driving?

 

[AMGeed]

Am I right in thinking the purpose of the "SBC Hold/Stop" function was to allow the car to slow itself down/stop the car at low speeds, as jdrrco said, for stop-start town driving?

I think its more a function to hold the car on the brake on a hill/slope so there is no need to keep your foot on the brake at all.

 

[mersum1es]

yep Stop function was made for traffic rush, hold function (which you have btw in in newer cars too) is to hold car on traffic lights etc. without pressing break pedal, especially when auto transmission has small traction on wheels all the time and car will drift unless hold in brake.

 

[MD5]

Am I right in thinking the purpose of the "SBC Hold/Stop" function was to allow the car to slow itself down/stop the car at low speeds, as jdrrco said, for stop-start town driving?

This is how it felt to me, as if the parking brake has been left on when you decelerate.

 

[MD5]

I think its more a function to hold the car on the brake on a hill/slope so there is no need to keep your foot on the brake at all.

Just to clarify, the two different functions are selected differently. One is with a second, harder press on the brake pedal, the other is by engaging the cruise control stalk at pedestrian speeds/standstill.