Trailer Stability Assist

[CraigH]

After reading many posts on trailers not being recognised by the vehicles computer so not turning off rear parking sensors etc, I noticed that some also say that the vehicles Trailer Stability Assist system is not activated.

According to LR own promo video on Trailer Stability Assist they say

"it operates up to maximum vehicle speed and does not require the trailer electrics to be connected"

Can anybody throw some light on this this?

What does actually change to the vehicle when a trailer is recognised?

Is it just lights and parking sensors or a whole lot more like transmission shift points, fuel metering, suspension behavior etc.

Cheers
Craig

[mowog]

I know how well the stability system works from first hand experience.

That aside I am sure the D4 would be aware of the trailer in a number of ways. Rear suspension load would have to be one. I am sure the Stability Yaw sensor would also detect the difference.

[Stuart02]

After reading many posts on trailers not being recognised by the vehicles computer so not turning off rear parking sensors etc, I noticed that some also say that the vehicles Trailer Stability Assist system is not activated.

According to LR own promo video on Trailer Stability Assist they say

"it operates up to maximum vehicle speed and does not require the trailer electrics to be connected"

Can anybody throw some light on this this?

What does actually change to the vehicle when a trailer is recognised?

Is it just lights and parking sensors or a whole lot more like transmission shift points, fuel metering, suspension behavior etc.

Cheers
Craig

I was only guessing re the trailer stability assist, but the towing section in the D4 manual definitely says the lower gear shift points are changed...

[rmp]

TSC doesn't know the trailer is there until it gets out of line. The sort of forces a swaying trailer impart to the vehicle are quite distinct from the forces when the car under or oversteers. The trailer will move the back end around - technically, the slip angle of the rear tyres will be much greater than the front, and then it'll rapidly reverse as the trailer oscillates quickly. You wouldn't get that behaviour without a trailer. Yes, there's "tank slappers" but their rate of oscillation is nowhere near as great and to keep a slapper going you need to do something (wrong) with the controls. To keep sway going you need do nothing as once started it just builds up until death. The computers can tell the difference. Fundamentally though the programme is the same, detecting an car out of balance and applying brakes indvidually to bring it under control. Therefore, TSC is a subset of DSC, as is CBC and ARM.

There are other reasons to detect trailers on cars but TSC isn't one of them.

[CraigH]

Thanks for the responses guys. Kinda thought this was the case

Craig

[sniegy]

TSA will work up to the maximum speed of the vehicle regardless of towing electrics being detected or not.
The difference will be the oscillation count when a trailer is connected.
A higher count when a trailer is not connected.
So it pays to have the towing electrics working properly when you are towing something.
The things that happen when trailer electrics are properly detetected are:
TSA works correctly-got to be a good thing
RPA is turned off-stops that beeeeeeeeeeeeeep when you select "R"
Reverse lights are turned off-stop blinding you at night when you select "R"
Air Suspension Height Selection is turned off-Hmmm not sure of the benefit
The light on the dash flashes ;)-you paid for it, gotta see it work:eek:

HTH
Cheers

[Graeme]

Air Suspension Height Selection is turned off-Hmmm not sure of the benefit
ISTR its either the auto extended height function or auto off-road height selection for a specific TR setting that is disabled.

[roamer]

ISTR its either the auto extended height function or auto off-road height selection for a specific TR setting that is disabled.



And I think the lowering at hi speed (160 kpm?) is disabled also.


Who wants to do 160kpm when towing to check ?

:burnrubber:

[Graeme]

Who wants to do 160kpm when towing to check ?
The Top Gear fellas should be up to it - been there...

[sniegy]

The Top Gear fellas should be up to it - been there...
[thumbsupbig] works well.

[Mike_S]

[thumbsupbig] works well.

Yep, it does. My RRS was as steady as a rock with a race car trailer on the back on an unrestricted road. Couldn't do it for long though, the fuel bowser couldn't keep up :p

[sniegy]

Mike,
The only downside of the V8, but gee they sound great;)