05 CTT traction control school

[ciaka]

Can someone tell me in great detail the mechanisms involved, the actions, etc that manipulate the traction control on the CTT? I really want to know everything involved to be able to understand in great detail how it is engaged, how the decisions are made and what sounds, feeling are involved when it is working. Thanks. Its the nuances I am interested in.

[darrinsmith]

What surface are you driving on?

If it's boggy sand I can tell you from experience that the traction control in the cayenne BLOWS CHUNKS on boggy sand.

It robs power right at the point when you need it the most, ie it doesnt allow enough wheel spin/slip to be effective in sand.

Unlike thue range rover etc that have a sand setting. That setting allows more wheel slip before reducing the power.

It's the strangest sensation having your foot to the boards, and the engine is just idling which you slowly sink into the sand....

Cheers!

DS

[mcbit500]

The only way to drive a Cayenne in soft sand is in low ratio with centre diff engaged. In high ratio the PSM pulls the plug on the power as soon as the wheels start to spin.

[mudman2]

I had my S in deep dry sand, I had no trouble, PSM off, high revs and don't chicken out

[mcbit500]

Done that too we have plenty of deep soft here, only so much pressure you can let out of 18" rims! Even with the PSM off it will pull the power as soon as you start to spin, much better with the centre diff-lock in.

This sort of stuff is OK in HR but you don't want to go into a blow hole without less than 15 psi in the tyres and centre lock engaged.

[clarksongli]

i like how no one actually answered the original question haha.

for clarification, i think the poster was looking to understand the mechanics around the system, not if it works well in sand.

PSM controls both brakes and engine power. So with wheel slippage PSM is able to both reduce output power as well as brake individual wheels depending on individual wheels speeds.

The newere cayennes also have additional features related more around road safety than offroad ability.

[mcbit500]

Agreed, perhaps that was a cunning plan. :) However he was requesting in great detail the mechanisms by which PSM functions, which are indeed quite complex, not the basic principles of operation.