Thread: D4 surge while towing uphill

Originally Posted by rifi1

I had no fault codes either.
Its booked back in to dealer in Perth in late Dec when I'm back up there but its going to be hard for them to test without taking my van with me.

Its easy to remove the plastic cover and reach behind the valve body to feel if the spindle moves freely or not. The spindle is operated by a vacuum chamber the return spring of which offers little resistance. I didn't know what was involved so removed the valve body to clean away the grit but next time I'll just spray some WD40 or silicone spray in the vicinity then work the spindle free.

We have noticed same on our 2013 RRS at times. According to dealer, this is the Gradient Response kicking in. A nanny system that I asked to be turned off while at the dealer, they couldn't do it unfortunately. This detects hill's/gradients and moderates the throttle/holds brakes on etc. Possible? Have noticed a few times on inclines pulling away and all of a sudden throttle seems to be disconnected. Then away it goes after a big shove. Also no fault codes shown.

Originally Posted by Meccles

We have noticed same on our 2013 RRS at times.

This is only when stopped with brakes applied to prevent rolling back when the brakes are released. My 2010 D4 is supposed to have the feature but I've not noticed it operating.

Can you turn trailer stability off ?
I think it turns on auto when trailer plug goes in.

Cheers Ken

Originally Posted by Meccles

We have noticed same on our 2013 RRS at times. According to dealer, this is the Gradient Response kicking in. A nanny system that I asked to be turned off while at the dealer, they couldn't do it unfortunately. This detects hill's/gradients and moderates the throttle/holds brakes on etc. Possible? Have noticed a few times on inclines pulling away and all of a sudden throttle seems to be disconnected. Then away it goes after a big shove. Also no fault codes shown.

Gradient Acceleration Control takes Land Rover’s helpful technology to a new level; enhancing the standard Hill Descent Control. Gradient Acceleration Control helps reduce, and smooth out the effects of the sudden initial acceleration that can occur when the vehicle enters a steep gradient.

What the ? How does this help ?

Brett

Originally Posted by roamer

Can you turn trailer stability off ?
I think it turns on auto when trailer plug goes in.

Cheers Ken

I believe if you leave the engine running when you connect your trailer plug it stops it from turning on, i might be wrong but the trailer indicator light doesn't appear when i connect this way.

The Gradient control works while moving as well. First noted when backing down a reasonable steep drive, no issue then up the reverse camber of the road. Accelerator pedal was like we had switched into Snow/Grass terrain response. A Looonng push on pedal, nothing. Then all of a sudden, away she goes. The same has been happening at times when entering roads/roundabouts, that have an incline. Car is going, push on throttle, nothing. Then all of a sudden, it takes off. Not good. But, according to Dealer, normal. I will be monitoring and seeing if it gets worse. Happened the other day on a roundabout and we were almost left stranded. Backed the trailer up the drive the other day, all good on level ground. As soon as I hit the relatively small incline up the drive, I lost throttle response. Had to use Low Range to get any sort of fine control. Again though as per Dealer, "normal" and part of Gradient Accelerator control to prevent me suddenly losing control of car because I am on a hill. I mean wtf?

Have you tried the manouvers using sport mode to make sure its not indecision on the part of the gbox? As for dealers saying something is normal, I'm reminded of my 1st TD5 D2 that I complained bitterly about for a long time only to discover myself that a swapped MAF overcame the issues, but not until well out of warranty.