I have a 2015 Octavia Scout with a haldex clutch as part of thge rear diff.

I am wondering about what sorts of events and or sensors control the activation of this clutch and so the rear wheel drive,

My experience and driving experiments suggest that rear wheel slip makes the clutch engage.  Also seems to be much more active in sports mode.  And if manual gear selection is engaged.  Also works better with heavy throttle use.

On a dirt hairpin at relatively slow speeds with sports mode selected flooring it will get oversteer happening. And it behaves more like a Subaru getting cleanly through and out of gravel corner with sports mode and plenty of throttle.

 

So does anybody know what the actual rules are for Haldex engagement?

 

And is it possibe to put in a switch to fully engage the clutch to get full rear wheel drive for difficult 4WD situations.?

 

Trevor

 

 

The Haldex controller reads information from many sources.  Steering angle, throttle position, wheel speed sensors, engine revs (and as such probably torque) and probably inclination & clutch pedal switch to try and give a predictive behaviour. So if you have steering angle, high revs and are intending pulling away quickly out of a junction then the Haldex will already be active.

It won't be possible to put in a switch to give full rear wheel drive because it's still gonna be front wheel drive by default, so junless you find a way to disable the front wheel drive then you'll only ever get 50% rear at most.