1999 S80 T6:

I tried the 'W' winter mode the other day. i.e for starting out on an icey road. i.e. pressed the 'W'button on the console to the right of the shifter
Don't know if there one is only supposed to use this for starting out with the wheels turned to 'straight ahead' or ???
At one point, maybe fifty feet from my starting point and possibly while I was turning the steering wheel, the left end of the front of the car made such grinding noise that I thought 'there goes the tranny into a thousand pieces'. The noise stopped while I was still moving and I pressed the 'W' button to get out of the 'Winter mode'. The car drove fine and I haven't had that terrrible noise/scare since the one time.
Has anyone else had such an experience?
I can't see why it should matter if one is turning the wheel unless it has/had something to do with the differential.

 

umm maybe your ABS kicked in ?

W means wet/winter, this system prevents wheel spin but cutting power when the computer detect slippage...its a nice feature but takes a moment getting used to, i always use it when i have the chance

as far as the noise, try to see if you can duplicate it...this will tell you if this "W" mode is causing it...

 

it should make that noise even with W mode off, as your STC will still be on. Does it sound more like a rake against pavement or a scraping noise?It could may have been the tire rubbing against the inner wall too, which is common.

 

Yea possibly rake scrap on pavement or even worse. Sure didn't sound like anything I've heard before. Sounded like parts were going to be strewn along the road. Why would it make so much noise?
Definitely was not tire rubbing. Steering wheel was only turned a very small amount.
Thanks.

 

I tried "W" button also on slipery surfaces. I also got that horrible noise. I turned of "W" ant STC and tried again. The noise was gone. So, i figured that it has to be the way these systems work.

 

The traction control utilises the ABS to stop a spinning wheel, hence the 'grating' noise which is normal. Once the wheel stops spinning the noise stops.

 

yeah i had a real snow fall today and tired things in the parking lot and its definitely the same noise you are hearing, and W does nto cause it, its the STC acting on the brakes

Volvo designed it a bit too loud, but hey its not the first thing that i think volvo "over" designed on this car.. so no worries, its normal

 

I too have had the opportunity to make use of the "W" driving mode. I like it. I would describe the effect as a flattening of the throttle response curve or as some people say, a "de-tuning". Assuming that all is well with your car, the horrible noise you heard may very well have been the traction control kicking in and which as billofdurham said, the traction control utilizes ABS. Have fun with your winter driving!
________
Xtube

 

We are having some non-global warming weather. (Wonder if Al Gore can send us some of his Nobel price money for snow/ice removeal?) So gave me a chance to see the traction/stability control in action again when driving up our icey drive way. The noise is definitely the ABS unit doing its thing. Big sigh that it is not the tranny going south....[/align]

 

This is straight from Vadis:
"Shifting program

Economy mode
When driving at normal acceleration, the gearbox control module (TCM) uses a pre-set shifting program, optimised to shift for economy driving. This shifting program is suitable for “normal” driving which provides earlier up shifts and lock-up. In addition the gearbox oil pressure is adjusted to provide smooth gear engagement.

Sport mode
In the sport mode shifting program the shifting points are adjusted to provide the best possible performance. Downshifts occur earlier. The gearbox control module (TCM) selects the shifting and lock-up points which provide the best possible performance. The gearbox switches from economy mode to sport mode in step 1 or step 2 if the accelerator pedal (AP) is pressed down quickly. The conditions are that the throttle opens and the vehicle speed exceeds 50 km/h. As soon as the accelerator pedal (AP) is released to a certain level economy mode is resumed.

Kick-down program
At wide open throttle (WOT) the kick-down function is engaged which provides quick downshifts for maximum performance. In this way a boost of power is achieved when overtaking for example.

Winter mode
Winter mode is selected using the (W) button on the top panel of the gear selector assembly. Winter mode enables starting off in a high gear to prevent the wheels from spinning on a slippery surface. This mode can also be used in other difficult situations in which the driver needs more direct control over gear selection. Lock-up can be engaged in 1st and 2nd gear. The shifting pattern is optimised to minimize the number of shifts. Depending on the gear position, the following combinations can be obtained:

-D The car starts in 2nd gear. Automatic shifting between 2nd and 3rd gears occurs earlier than in Economy mode, D position
-3 The car starts in 2nd gear. 4th gear is locked out
-2 The car starts in 2nd gear. There is no up shifting or downshifting
-1 The car starts in 1st gear. There is no up shifting or downshifting.

The W lamp on the dashboard lights when winter mode is selected.
If kick-down is activated in Winter mode, the gearbox uses all gears for maximum performance.

Other modes

Adaptation
The gearbox control module (TCM) monitors each shift during all driving conditions to ensure consistent and smooth gear shifts. The control module does this by either lowering or increasing the hydraulic pressure used during the shift itself. The changed pressure levels are stored in the control module memory when the car has been switched off and are retrieved on start-up. This provides improved shifting comfort and increased service life.
Adaptation occurs when the following conditions have been met:

-Throttle opening is steady
-Oil temperature between 50 °C and 110 °C."

not too shabby