Does anybody know, if you turn off the traction control, what aids are truly turned off? Especially I am interested if electronic brake distribution, corner braking and vector torqueing is disabled or not.
I have red user's manual and the 23000 pages repair manual but I haven't found what is truly off.
Thanks

 

If I recall correctly, there is a reduction in DSC called "TracDSC", and then completely off which is DSC off. You probably won't hear from anyone that completely turned DSC off because they are dead.

 

Supposedly, holding the traction control button down for 5 seconds turns everything off. A shorter press allows limited wheel spin. I doubt anyone knows exactly what is happening in any of the three modes, as there are a lot of interacting inputs and its probably changed over the years.

The important thing is that with the cheap stock PZero passenger tires, the car is pig on roller skates regardless of mode but AWD is a big improvement for obvious reasons. With the best performamce tires money can buy, both RWD and AWD cars are p.u.s.s.y cats in all three modes, even at a fully tuned 650 BHP.

All road tests should be discarded as useless disinformation, or even opposite to reality, as guys like Randy Pobst and Matt Farah spend 10 minutes with the car and don't even understand how the button works let alone the impact of tire differences.

 

I would second that. When I moved from my '07 XKR to 10 'XKR I was wary of the car because the Dunlop Sport Maxx's on the car were hopeless, especially when the road was damp.

Switching to Michelin Pilot 4S's gave me the confidence to significantly boost the cars power and it is still very predictable to drive.

 

The stability assist system overview on TOPIx is lacking detail on TVB, but covers the rest:

CBC (Corner Brake Control) counteracts the yawing moment produced when braking in a corner by limiting the brake pressure on one side of the vehicle. This is only active with DSC or TracDSC, with the later having an increased threshold.

ETC (Electronic Traction Control) attempts to optimize forward traction by reducing engine torque, or by applying the brake of a spinning wheel until traction is regained. Only active with (full) DSC.

EDC (Engine Drag-torque Control) prevents wheel slip caused by a sudden decrease in engine torque when the accelerator is suddenly released, or a downshift using the Jaguar sequential shift function. There is no mention of DSC for this one, so it may be on or off.

EBD (Electronic Brake Force Distribution) uses the ABS braking hardware to automatically optimize the pressure to the rear brakes, below the point where ABS is normally invoked. Unaffected by DSC.

TVB (Torque Vectoring by Braking) reduces near-limit understeer of the vehicle, during cornering by braking the inside wheels, increasing the yaw moment acting on the vehicle. There is no mention of DSC for this one, so it may also be on or off.

The only changes between full DSC and TracDSC appear to be the ETC being disabled, and the CBC threshold being increased.
With all DSC off the CBC will be disabled entirely, but TVB is still an unknown. Logically... you would think it would be disabled as well as it doesn't make any sense in that context.

 

Turning DSC off entirely will not disable ABS, nor will it affect the operation of torque vectoring by braking if you have the super performance TVB big brake package. TracDSC is merely a less interventional mode than the full DSC. It will not reduce throttle by as much or for as long as the full mode when loss of traction is detected. That said, a reasonably skilled and attentive driver should be able to secure good traction control without DSC. 5 decades of driving without using DSC and I’m still alive. I will, however, use it when I expect conditions of standing water.

 

I never drive with the DSC on.... Especially in Winter! Car is very composed and AWD works very well to help keep you moving forward. Not suggesting this to others, but I don't feel like the car is ever doing things that I'm not asking for. As for OP, I think the 3 modes (on, trac, off) give you a great selection of intervention for whatever your needs may be.

Love the drive!

 

From what I gathered around the web and my personal experience, there are 4 stages.

1, DSC on, all the nannies are on
2, Press for 1 second, Trac DSC, all the nannies are on still, but slightly less restrictive
3, Press for 3 seconds, DSC OFF, all the nannies are on still, a lot less restrictive
4, Press for more than 10 seconds, DSC OFF completely, all the nannies are off, including active torque vectoring and engine power limit

I had the fortune to have access to an empty parking lot covered in snow last night, too bad #3 didn't completely turn off the DSC and it intervened with braking and power limiting. By the time I searched the web and came to the answer that you have to hold the button for more than 10 seconds to turn everything off, the snow had cleared, and I don't have the skill to try it on clear road. Plus holding it for more than 10 seconds does not introduce a new or different icon on the gauge cluster, it was the same as holding it down for 3 seconds.

I'm eagerly waiting for the next snow and try it out. It'd be nice if someone can confirm #4 is true and if not, how do you turn everything off. Looking through the owners manual yielded nothing.

 

Haven't tried it myself, but from all my reading the settings are 1, 2 and 4, never read or heard of your setting 3.

 

You aren't getting confused with the XK/XF are you because I have to press the button for more than 10 seconds in my XKR?

This is from the F Type Owner's manual:

 

Yep, you are dead right!
I just went and checked and it's just as the Owner's Manual says - press once for Trac DSC and hold for 3 seconds for DSC off. Holding for another 10 seconds or so makes no difference, well at least no further or different message was displayed. On both my old XFS and XFR you had to hold the DSC button down for at least 10 seconds to turn DSC fully off. So maybe Ray Ray is correct and he has stumbled upon a twist we didn't previously know about - three levels of DSC off - Trac DSC, Off DSC but not really off, and really honestly truly Off DSC!

 

I revisited the sites and indeed they were for XK/XKR and STR
https://www.jaguarforums.com/forum/s...dsc-off-46594/
https://www.jaguarforum.com/showthread.php?t=71217

The question remains though, how to turn DSC completely off, or holding the button down for 3 seconds is indeed completely off and I was doing something wrong?

It was clear to me that the power were being cut completely and brake repeatedly intervened during a slide. Though there were a few instances where it allowed me to spin a few times and allowed wheel spin. I will find it out next time it snows here.

 

I was invited by the main JLR dealer to an event on a frozen lake in Norway this weekend. We drove most JLR models (including the SVR model from Range Rover and F-pace, and the awd F-type S).

We drove on several different tracks that where made on the ice, including a 3 mile circuit, and a shorter oval drift circuit.

My personal experience with dsc off in most models was that the system would still interfere, and when "very sideways in very slippery conditions", the system would occationally not let you give more power.

The F-type (and the two rwd Astons - one Superlegera and one Vantage) was the exceptions. With dsc off, I could not feel any interference. The only "problem" with the awd F-type was that it was not always so easy to predict the power distribution between front and rear, which ment that you needed to work a bit harder to hold a long drift and at the same time hold the position were you wanted through the curve. You loose more traction on the front axel when power is shifted frontwards due to very little traction on the rear when very sideways.

It was easier to hit the apex correct with the rwd Astons, as traction on front wheels where more predictable.

Great fun on the ice though 🙂


The Superlegera.

Our "booring" everyday car. I don't have wintertires on my F-type.



From the parking area.

 

Having read a few of my Jaguar technical manuals I think xdave has provided a pretty accurate summary. One interesting thing I did find in the 2014 chassis systems student guide was this though:

Even when DSC is deselected, driving conditions with extreme yaw or lateral/longitudinal
acceleration may trigger DSC activity to assist the vehicle stability control.

Having said that, although it actually has a few colour photos of F Types in it the manual only seems to specifically cover the X150 XK, the X250 XF and the X351 XJ.

 

Hmmm. Interesting that RayRay feels interventions and Arne not when DSC OFF on snow.

Just for fun how some cars works (my previous Toyota FR-S) how to disable EBD and Ice Mode:
- Turn on the car. The car must be FULLY warmed up. You must do the entire sequence within 30 seconds of starting the car.
- Pull the e-brake 3 times. Hold/lock the e-brake on the 3rd pull.
- Press the brake pedal 3 times. Hold it down the third time.
- Pull the hand brake 3 more times. Hold/lock the hand brake on the 3rd pull
- Press the brake pedal 2 more times.
- On the last press of the brake pedal, two yellow lights should have come on.

 

I do have a nice video of the F-type drifting through a 180 degree curve, and where you can see and hear the power applied when going very sideways.

It's on my phone, but it's not possible to upload it here.
Edit: does this link work?:

 

I wanted to respond earlier to this, but WiFi in my crypt is spotty. DSC off won't kill you, not knowing how to drive without electronic aids would.

 

Anecdotally. On my local track there is one road segment where optimal line gets you to crest diagonally. This crest is not an issue for road cars, where available torque and suspension setup allow one to WOT across it without upsetting car dynamics. However, with full traction enabled, my F-type detects slight tire slip and cuts the throttle. It does not do this with TracDSC.

 

"Trac DSC" does an OK job handling RWD power even with the tune and upgrades while corning and actually driving. I usually only go "DSC OFF" (5 second button hold) for this kinda of stuff or intentional drifting...I have gotten in trouble before forgetting that i turned it off, but it will remind you with some tail wags in the first aggressive corner.

 

I like it! We need more videos showing how to enjoy the F-Type's power.