Loss of power in rock mode.

[Spence]

Just wondering why whenever I tackle a very steep Hill, in rock mode, I experience a huge loss of power. Sometimes to the point where I could put the pedal to the ground, and it won’t move at all. Anyone else experienced such a thing? Can’t find any other threads here, with the same issue. Cheers.

[101RRS]

Do you have DSC turned off?

[Graeme]

How's the gearbox oil level?

[Spence]

Do you have DSC turned off?

Yes,I always turn it off. Not sure if that’s the right thing to do or not. Just habit from when I had a Jeep. In new to the D4.

[Spence]

How's the gearbox oil level?

This vehicle is fairly new to me. It is going in next week for a full service. I shall have that checked. Will this make a big difference? Should it lose power like that if low on oil?

[loanrangie]

You realise that the throttle response is reduced in rock crawl mode ?

[Disco-tastic]

I had the same thing when tackling a steep muddy hill. I put it in rock crawl as i thought the quicker it locked the centre diff and stopped wheels spinning the better. What i found was that the computer would cut throttle if it sensed spinning wheels and sudden changes in any direction, such as jostling from either from ruts or bumps.

I figured it was programmed to think, in that situation, that control had been lost and cutting power was the safest option. That or the higher speed was freaking it out (i wasnt exactly crawling).

I never got a chance to try the same hill in mud ruts or sand mode though i am assuming they would have performed better as they allow more wheel slip and jostling before stepping in.

And yes, even with the DSC off the DSC can still intervene.

If you get a chance try the same hill in mud ruts or normal. Sand mode will give you very sudden throttle response so i wouldnt recommend it first thing.

And let us know how it goes!

Cheers

Dan

[Spence]

You realise that the throttle response is reduced in rock crawl mode ?

Yes, I realise it is reduced in rock mode. But in this case it wasn’t reduced, it was pretty much zero. No forward motion at all. I was going slow and controlled but the power just got less and less until there was nothing.

[Spence]

I had the same thing when tackling a steep muddy hill. I put it in rock crawl as i thought the quicker it locked the centre diff and stopped wheels spinning the better. What i found was that the computer would cut throttle if it sensed spinning wheels and sudden changes in any direction, such as jostling from either from ruts or bumps.

I figured it was programmed to think, in that situation, that control had been lost and cutting power was the safest option. That or the higher speed was freaking it out (i wasnt exactly crawling).

I never got a chance to try the same hill in mud ruts or sand mode though i am assuming they would have performed better as they allow more wheel slip and jostling before stepping in.

And yes, even with the DSC off the DSC can still intervene.

If you get a chance try the same hill in mud ruts or normal. Sand mode will give you very sudden throttle response so i wouldnt recommend it first thing.

And let us know how it goes!

Cheers

Dan

I go to this area quite often. As soon as weÂ’re allowed out, I will tackle it again and experiment with different modes, and have a bit of play around.

[TuffRR]

It is likely DSC kicking in, which does happen in various modes. Some more aggressive than others. From memory mud/ruts is the least aggressive as it expects a certain amount of wheel slip.
I think also it sometimes has a self preservation mode kick in. A few times i have been bound up on a rock ledge or in mud and no matter how much i want power, computer says no. I put this down to some smarts which is protecting components.