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-   -   Auto Hold: Most convenient yet neglected feature! (https://www.team-bhp.com/forum/road-safety/270387-auto-hold-most-convenient-yet-neglected-feature-2.html)

Oh I agree. But I get that, it's one of those features where once you go for it you can't go back. I hope it trickles down like everything else. Maybe because I don't drive in similar routes, perhaps I'm unable to relate as much. Most of my issues are dealt fine with a proper auto box, but yeah, I would perhaps be happier to have auto hold and can see how it can be more convenient for routes like the one you've mentioned.

100% will. Hyundai-Kia are already offering this very-useful feature in their mainstream cars (Seltos, Creta etc.).

That being said, I am in the minority. Although I own two cars with auto-hold, I prefer to keep it off. Main reason = I find it jerky.

I think you need electronic parking brake for it and I am not sure may be all four disk brakes. So I think on lower end cars it probably will be skipped.

I find it utmost convenient to use my it in Bangalore traffic in my A6. It does the job super well. I also think it has a sensor and it auto starts and crawls when the vehicle in front starts moving forward, without me having to give accelerator input. I simply love this feature.

Pretty sure it's not how it works on the new Kia Seltos. Creeping doesn't work alongside auto hold. Maybe this is a luxury feature

Yes. In Merc Auto hold is turned on by default. I believe it's not switchable.

I believe so. I think this feature is misunderstood for hill hold function. I feel many fellow BHPians are driving cars with this feature without using it. Actually this feature is very handy in dense traffic with plenty signal crossings.

Absolutely true. The auto hold function gets coupled with electronic braking. But I don't think you need all 4 disk brakes. I am also not so sure about it.

I think he is talking about adaptive cruise control. Only adaptive cruise control can auto brake and accelerate as mentioned.

Ah, true, my bad! Thanks

Jeroen

Its needs an ESP system, which is the one holding the vehicle at a stop. To work properly, it also needs bi-directional wheel speed sensors, which are a bit more expensive. And like you said, EPB is required, though not mandatory (there are several vehicles with Auto Hold without EPB). Though not directly related to ADAS features like ACC/AEB, they do share a lot of SW code between them. One of the reason why a lot of vehicles have Auto Hold + ADAS as a combination.


I believe that would be the Stop & Go feature of ACC. Auto Hold needs a driver brake event to initiate the hold.


Let me give a brief description of Auto Hold from a SW point of view:

Once the feature is turned ON, it waits for the driver to brake the vehicle to standstill. Eg. at a traffic stop. Once at standstill, the driver can take his foot off the brake pedal. Auto Hold will maintain the brake pressure upto a specified amount of time. Once the driver decides to go and presses the accelerator pedal, Auto Hold slowly releases the brakes.

Different companies/vehicles models use permutations and combinations of this basic logic.

Does it strain the gb and clutches in a dct gearbox?

Really OT : You mean to say, it is not necessary to shift to D or P at the traffic light.

If the wait time is more say above 40 Sec, what do you do?

Thanks for the info.

I absolutely loved this little feature in my Toyota's and Nissan Qashqai.
None had any jerks and would smoothly release the brakes.

Very useful at a redlight ensuring the car does not roll forward / backward.

Only annoying thing about it; Toyota resets it to OFF every time you turn the car off.
The Qashqai kept it ON for good!

I am yet to drive a car with this feature but few years back when I got to know about such feature, I had decided my next must have this as and when I decide to have it. It would be a big relief for your right leg.

For users of cars with DSG/DCT, I have a question. Do you know when the auto hold is enabled, does it disengage the clutch of DSG/DCT gearboxes, when the car is stationary during stop-go traffic? If it does, then it would address the biggest painpoint of DSG failures which are attributed to stop go traffic of India. VW had recommended to keep shifting the stick of DSG boxes from D to N in such traffic to save the clutch, which may not be required when you have auto hold.

Is there any negative impact of using Auto hold on fuel efficiency? I read that you must press the accelerator more when the Auto Hold has been engaged, which might cause FE to drop. Any leads appreciated.

I think it does. The gearbox is driving the car forward and the brakes are holding it back.

DCT disengages the clutch completely once the vehicle comes to a stop, so its effectively in neutral. Auto Hold doesn't cause any extra stress to the gearbox. It just eliminates the need for the driver to keep the brake pedal pressed.