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Discussion Starter · #1 · (Edited)
I would like to get confirmation as to how the "Hill Start Assist" (HSA) feature is supposed to work in a 2018 SPA XC60 T6 automatic (with air suspension).

We have an OSD 2018 V90 Inscription as well as a USA stateside delivered 2018 XC60 Inscription. Both the V90 and XC60 have updated software. (The XC60 was updated just yesterday, 9/18/19.)

Here's the except from both the XC60 and V90 owner's manuals describing the HSA (both manuals have the same wording):

Hill Start Assist

The function for assisting when starting the vehicle
on inclines, Hill Start Assist (HSA), helps
prevent the vehicle from rolling backward when
starting on an uphill gradient. When backing up
a hill, HSA helps prevent the vehicle from rolling
forward.

The function retains pressure from the brake
pedal in the brake system for several seconds
after the brake pedal has been released.

This temporary braking effect is released after a
few seconds or when the driver begins [accelerating].

Hill Start Assist is available even if the Auto-hold
brake function is switched off.



In our 2018 V90, the HSA works exactly as described in the owner's manual. That is, on a slight uphill when I come to a stop, the Start/Stop mode stops the engine as expected, and when I release the brake (having been still for a second or two) the engine restarts as expected. At this time, the HSA system keeps the brakes applied for a couple seconds after which the brakes are released by the HSA system and the vehicle begins to move forward (even at idle). If I use the accelerator before HSA automatically disengages the brakes, my action overrides the HSA timing and the brakes are immediately disengaged, and I am on my way. This is exactly as described in the owner's manuals.

And I am perfectly happy with this design. The V90 operates exactly as it should.

But with the XC60, the HSA does not engage.


Both cars are always operated with Start/Stop enabled; and, the Auto-hold brake function is not used in either vehicle.

Neither car has ever had trouble starting after being turned off for days at a time.

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Now here's the rub...

The V90 is driven 5 days a week for about 50 miles a day and for about hour or two, depending on traffic. The Start/Stop feature always works providing all the Start/Stop operating conditions are met as listed in the owner's manual.

On the other hand, the XC60 is driven only 1 day a week for somewhere between 10 and 25 miles, and only for 30 to 45 minutes on those days. And, as you might expect me to say, the Start/Stop mode does not becomes active. In fact, I have seen the Start?Stop mode being "Ready" only one time (yes, the new "ready symbol" (white, green, or crossed off white) has replaced the word "Ready" in the updated software).

The dealer told me that the battery(ies) in the XC60 are not being fully charged because of the short driving time experienced by the XC60, and that is why the Start/Stop never becomes active. Perhaps, but as I told them, even after driving for over 90 minutes under ideal conditions, the Start/Stop still never becomes active.

I suggested to the dealer that the Support Battery (in the engine compartment) should be changed. They would not do it under warranty, and was told that I need to put a battery charger on the XC60 every night.

That is simply BS. And I'd bet I could be accused of doing something detrimental to the vehicle when they see battery clamp marks on the proper charging connection terminals as shown in the manual.


Anyway, my questions are these...

Is the HSA supposed to work regardless of whether Start/Stop is enabled? Must Start/Stop not only be "Ready" but also activated upon a stop?
Can HSA be operational when Start/Stop is disabled?
What if Start/Stop is enabled but all the required conditions are not met (e.g., too warm, too cold, driver's seat belt unbuckled, etc.) so Start/Stop does not activate when you stop...will the HSA function at that time?
 

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My V90 CC 2018 never applies hill stop unless the engine stopped, meaning if I disable stop feature I never had the hill assist working. When I contacted Volvo about this they said is normal.

By comparison I like the way Mercedes does it, press lighter on brake while stopped is not activating it, press harder to the bottom while stopped then is activated.


Sent from my SM-G950W using Tapatalk
 

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...I like the way Mercedes does it, press lighter on brake while stopped is not activating it, press harder to the bottom while stopped then is activated.
Agree. The "keep pressing through while stopped" approach with the brake is a lot more natural, and what I had in my former Lexus, MBZ and now Tesla. I use it all the time around where I live. Volvo seems to be the odd man out with their different Hill Assist implementation, so it will take me a lot of getting used to. ;)
 

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the XC60 is driven only 1 day a week for somewhere between 10 and 25 miles, and only for 30 to 45 minutes on those days. And, as you might expect me to say, the Start/Stop mode does not becomes active.
Yes, if driven infrequently, you'll need a battery charger (trickle charger). The modern "always on" systems pull a decent amount of current when the vehicle is OFF.

For example, on average, I use my boat once per week and keep it on a solar battery tender when not in use. This easily doubles the life of the battery and keeps it at 95+% charge.
 

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Yes, if driven infrequently, you'll need a battery charger (trickle charger). The modern "always on" systems pull a decent amount of current when the vehicle is OFF.

For example, on average, I use my boat once per week and keep it on a solar battery tender when not in use. This easily doubles the life of the battery and keeps it at 95+% charge.
This is due to "energy saving" design nowadays that uses a less powerful alternator and takes longer driving time to top-fill the battery.
It is a poor decision to gain 0.x mpg but leave you a dead car in morning.
I hope the new mild hybrid system will help on recharging the battery on the go.
 
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