DSTC - yes or no in snow?

[paultyler1]

OK, worked out how to turn it off but would still like to know what the winter switch does.

[volvorocks]

Originally Posted by wagga

Leave DSTC on for normal driving.
Leave DSTC on for driving in slippery condition like snow etc.
Leave DSTC off if driving very slowly across deep snow, soft sand or deep mud.

TC is always on in all cases.

I was wondering about whether DSTC should be on or off,and after a bit of reading believe you are correct in what you suggest.

According to Volvo you cannot switch off DSTC, you just make it a little less responsive. Its kind of aways on, even when 'off'. When you switch DSTC off (in XC60) you place the car in Sport Mode which means that the DSTC doesn't kick in so quickly. Volvo recommend using the Sport Mode of DSTC when driving in deep snow for 'maximum tractive force'.

My conclusion is that in normal driving in normal icy and snowy conditions - leave DSTC on, and if you get caught up in deep snow temprarily switch DSTC 'off' (put it in Sport Mode) until you get going again.

On a seperate note has anyone used Hill Descent going up a hill in snowy icy conditions?

Regards

EDIT Just noticed this thread is about XC90..!! With the thread being by wimorrison thought it was about XC60. Still its about DSTC..!!

[volvorocks]

Originally Posted by paultyler1

OK, worked out how to turn it off but would still like to know what the winter switch does.

I believe the winter switch means the car starts in 3rd gear on autos.

Regards

[TruckbusUK]

Originally Posted by paultyler1

OK, worked out how to turn it off but would still like to know what the winter switch does.

Sorry to state the obvious, but its in your owners manual, and it looks like a new car, so you should have one.

Hope it helps

[paultyler1]

Yes, I know this is what the handbook says:

W – Winter
Press the W button to activate and
deactivate the winter program.
Display of the W symbol in the
combined instrument panel indicates
that the winter program is
active.
The winter programme starts the gearbox in
3rd gear to make it easier to pull off on slippery
roads. When the programme is engaged, lower
gears are activated only by kick-down.
The W program can be selected regardless of
the position of the gear selector, but is only
operational when the selector is in position D.

but is that all it does? Does it make all that difference?

[donturkone]

I got stuck in snow ditch last week... I could not get out the ditch by driving forward, I had to put in reverse and wit DSTC on I just drove out of the ditch... so IMHO, the DSTC is good for snow and mud...

[Carrizos]

A lot of 4X4s have a similar ability to the W button, it was a hold button on my Mitsi 4X4, as I understand it the aim of holding in 2nd, or in this case 3rd, is to reduce wheel spin when pulling away or driving slowly on slippery surfaces, I have not had to use it in my Volvo but it was very effective in my Mitsi especially when wallowing about in deep muddy ruts as it attenuated the potential to over rev due to the odd unintentional stab of the throttle.

[Nick2]

Originally Posted by donturkone

I got stuck in snow ditch last week... I could not get out the ditch by driving forward, I had to put in reverse and wit DSTC on I just drove out of the ditch... so IMHO, the DSTC is good for snow and mud...

Maybe a really daft question but does the AWD also kick in when car is reversing?

Thanks

Nick

[Mistero]

A Winter button - I thought 'I don't have that button'. A quick glance in the user manual confirmed that my manual XC90 won't have it.

I too have been out in the snow and ice and been impressed with the car on the slippery stuff. I've felt the AWD kick in and felt the way the DSTC straightens the car, too. It all felt very controlled, my days of power sliding are definitely behind me!!

Thanks for this thread, everyone, very informative.

[Philip76]

Reading through my old service manual DVD on the computer the other night, I found out that the car turns off DSTC by itself when it engages 4WD. The reason stated is that DSTC can interfere with the operation of 4WD. So that suggests that whether or not one turns off DSTC by pushing the button, the car will turn it off anyway.

This is why my car, with its malfunctioning control module for the rear diff coupling, has deactivated DSTC - it doesn't know whether 4WD is active or not. I would have thought it would be safe to assume that a non-communicating DEM would be unable to engage 4WD and therefore DSTC could stay on, but it seems Volvo thinks differently.