[ForesterBill]

Now that we’ve had some snow and ice on our mountain forest roads, I’ve had a chance to use X-mode. When in X-mode and going down a steep, icy grade with Hill Descent Control operating, I hear a very noticeable ratcheting noise from the right (passenger side) front wheel or engine bay area. The ratcheting (rapid clicking) noise is on and off every 5-10 seconds and it seems to occur when Hill Descent Control is automatically braking. The noise does not occur unless I’m going down a slippery surface.

I hear the same ratcheting noise when not in X-mode but while braking on snow/ice when the ABS system engages. It’s the exact same rapid-clicking (ratcheting) noise from the right front wheel/engine bay area (best I can tell from the driver’s seat).

I suspect this rapid clicking/ratcheting noise is related to the ABS system and not X-mode. However, I had ABS on my previous 2010 Forester and the only thing I noticed was a vibration in the brake pedal, no ratcheting noise. My previous Forester did not have X-mode.

This ratcheting noise is very noticeable. My passenger was quick to say “What is that?!” Is this noise normal under the above conditions?

 

[KLEMMER]

Read your owners manual. It clearly states while in x mode you will hear the systems make noise. Yes it is the ABS pump making the noise and is normal operation.

 

[ForesterBill]

I did read the ABS section of the owner's manual for both my current 2018 and former 2010 Forester. Both manuals make reference to the possibility of hearing a "chattering" noise when the ABS system is operating. However, the ABS system on my 2010 never made the noise that I am hearing on my 2018.

 

[slothman]

However, the ABS system on my 2010 never made the noise that I am hearing on my 2018.

Maybe you never braked hard enough to active it. There is a study using ECU data from crashed cars which found most drivers never do even in the direst emergency.

X-mode does, however, both to reduce speed and to stop a spinning wheel so that power is sent to those that do have traction.