Trailer sway control

[andyandee]

Hi all,

This topic may have already been covered so I apologise if this is a boring question!

I have recently bought a MY15 Discovery SE SDV6 and plan to use it to tow a caravan (ATM 2800kg).

I have the option of fitting sway control to the caravan but have heard that this can interfere with the Disco's trailer sway control system.

I'm very interested in any feedback from the AULRO community.

Cheers, Andy

[loanrangie]

Hi all,

This topic may have already been covered so I apologise if this is a boring question!

I have recently bought a MY15 Discovery SE SDV6 and plan to use it to tow a caravan (ATM 2800kg).

I have the option of fitting sway control to the caravan but have heard that this can interfere with the Disco's trailer sway control system.

I'm very interested in any feedback from the AULRO community.

Cheers, AndyCorrect you don't need it with any eas equipped LR.
Also I will move this to the correct section.

[DieselLSE]

What loanrangie says. Trailer Stability Control is activated when the trailer plug is inserted. If the trailer dash light illuminates when the turn signals are activated, then it is working along with a few other smarts.

[DiscoJeffster]

What loanrangie says. Trailer Stability Control is activated when the trailer plug is inserted. If the trailer dash light illuminates when the turn signals are activated, then it is working along with a few other smarts.

Not exactly correct. Trailer sway is always enabled, trailer connected or not. It’s a base function of the dynamic stability control. The vehicle senses a yaw motion not commanded by steering input and uses the brakes to counter it as best as physics allows.

[RANDLOVER]

Not exactly correct. Trailer sway is always enabled, trailer connected or not. It’s a base function of the dynamic stability control. The vehicle senses a yaw motion not commanded by steering input and uses the brakes to counter it as best as physics allows.

I thought the best way to control trailer sway was to apply the brakes to the trailer and not the car, so if one had lightning fast reflexes pushing the manual brake button on a trailer brake controller would stop sway.

[DiscoJeffster]

I thought the best way to control trailer sway was to apply the brakes to the trailer and not the car, so if one had lightning fast reflexes pushing the manual brake button on a trailer brake controller would stop sway.

Absolutely, and it doesn’t have to be lightening fast either as trailer sway builds up. I’m just saying how the trailer sway function works on the Disco. There’s a video somewhere online about it by them.

I think the system would struggle to stop sway induced by a poorly loaded trailer as physics tends to get in the way.

[RANDLOVER]

Absolutely, and it doesn’t have to be lightening fast either as trailer sway builds up. I’m just saying how the trailer sway function works on the Disco. There’s a video somewhere online about it by them.

I think the system would struggle to stop sway induced by a poorly loaded trailer as physics tends to get in the way.

That makes sense as a trailer brake controller has to be installed if towing over 750 kgs., so the car has no way of braking the trailer independently.

[Briar]

The Land Rover Trailer Stability Control will do whatever it can to keep the whole system (car + van) stable on the road. HOWEVER, one thing the LR TSC cannot do is apply the brakes on the caravan to prevent a Yaw/ Sway event. The optimum thing to do in the event of a caravan yaw event is apply the caravan brakes asap. This is why having a system ON THE VAN, such as Alko ESC is highly desirable, as it will apply the van's brakes quicker than you can ever respond. Having ESC on the caravan will not impact the Discovery's computer system (TSC). The TSC will only ever respond to what the van is doing and apply the cars brakes or cut power, based on what is being detected. Both systems will work in concert. IMHO, you'd be crazy not to get ESC on the van and just rely on the Land Rover TSC to stop a van swaying.

[DieselLSE]

Not exactly correct. Trailer sway is always enabled, trailer connected or not. It’s a base function of the dynamic stability control. The vehicle senses a yaw motion not commanded by steering input and uses the brakes to counter it as best as physics allows.
Might be, might be, I don't know. This is what the workshop manual says:
Trailer Stability Assist
When the trailer electrical socket is connected, trailer stability assist operates automatically to enhance the existing
DSC and terrain response functions of the vehicle when towing. The system detects sway movements caused by
trailer oscillations at speeds in excess of 60 km/h (37 mph) and acts to eliminate them. It does this through braking
and engine management. Braking management counterbalances the sway movement through symmetric and
asymmetric braking, thereby slowing the vehicle and eliminating the oscillations. Engine management adapts engine
torque output to support the braking management in stabilizing the vehicle and trailer.
Typical conditions when sway can occur include:
Changing highway lanes.
Traversing a lengthy bend.
Acceleration.
Braking.
The capability of trailer stability assist to respond early to the beginning of trailer-sway makes the system almost
unnoticeable under normal driving conditions and keeps the vehicle and trailer under safe control. Trailer stability
assist requires no input from the driver and operates up to the maximum vehicle speed.
Trailer stability assist will not operate while DSC is switched off.

[DiscoJeffster]

Land Rover Trailer Stability technology - YouTube (https://m.youtube.com/watch?v=cy4vfcX_BrU)

“.. and does not require the trailer electrics to be connected [emoji2369]…”

As most have their trailer connected and being sensed correctly, the issue is moot anyhow.

[DieselLSE]

Land Rover Trailer Stability technology - YouTube (https://m.youtube.com/watch?v=cy4vfcX_BrU)

“.. and does not require the trailer electrics to be connected [emoji2369]…”

As most have their trailer connected and being sensed correctly, the issue is moot anyhow.
Thanks for the vid. It makes sense that Sway Assist works without the trailer electrics being connected when you think about it. Picture a "worst case" scenario where the trailer starts swaying and the plug becomes disconnected (I dunno, perhaps hitting something on the road or a pothole or whatever). In this case, sway assist will still happily work. Requiring the plug to remain inserted creates a single point of failure.
Clever little D4!

[Pedro_The_Swift]

My van has er, one of them. capable of operating any or all 4 van brakes, And its powered by the vans batts so totally separate from any car connection,
so if the van pops off the hitch, by rights it should just pull up in a straight line...[bighmmm]
It also has this really stressful habit of dabbing brakes for no apparent reason.
It feels just like a total dead engine for half a second.:bat: