You're absolutely entitled to opinions but where the authorities have chosen things deemed safer and fatalities and injuries have dropped you're kind of out on a limb. No reason why the things you don't like should be mandated on private land, though, and here they're not. On public roads, they are mandated by law and with the idiots commonly on roads I can see why. I would not want them able to turn off things just because in their opinion that's what they wanted.

 

You haven't the least clue as to what has been 'mandated'. Hint: DSC is not on the list, and not all - or even very many - vehicles have it at all.

Perhaps someday someone will get it right and it will be less dangerous as to unpredictably altering the handling characteristics of the motorcar.. Until then, driving skills still matter, and sleeping or failure to pay attention is best NOT done while at the wheel.

Think it through: Even if the computer were faster, the sensors and servos must always react AFTER the fact of events.

They have no inputs to guide them as to what choices to make from a limited canned repertoire until 'something happens'.

Any even modestly competent driver knows IN ADVANCE what is about to 'happen'. After all, (s)he is the very cause of most of it, has a continuing plan, and a far broader toolset to-hand to implement it than DSC has.

And we are not at odds over ABS in the first place. It is much gentler on tires than oscillation braking, and fits far more situations.

It is but DSC that is the danger.

 

As with many other countries DSC/ASC/ESP/VDC/VSC, call it what you want, is being phased in in my country over the next few years.

The information on the government transport site (and similar info is on Wikipedia for that matter) says:

Electronic Stability Control

Is ESC mandatory in other countries?

Yes. The United States, Canada, Japan, South Korea, Australia and the European Union have all mandated ESC for new light passenger vehicles and, in most cases, light commercial vehicles.

 

Cogent, that.

All jurisdictions ordinarily require "whatever' equipment a maker shipped to be in working order. Most forbid altering or removing it.

Much more rare to require a blanket retrofit of new technology to older vehicles.

Worst-case, I'd have to leave the dangerous 2004-era DSC in its operational default "go ahead, try to kill me if you can" state. Then manually shut it off every time I start the car.

As I now do, it having proven itself consistently WRONG at every opportunity.

All the components are in good nick and work as they were designed to do.

NONE of them can see ANY traffic, nor the pavement a foot in front of them, let alone 'many' feet.

NONE of them are privileged to have the least clue where I plan to - or may be FORCED to - place the vehicle one second's time in the future, let alone two seconds or twenty seconds.

Blind where it matters most, they are. Result? where one can count-on ABS for a high degree of cooperation and predictable behaviour, DSC is the reverse.

Throwing EXTRA challenges - usually to be overcome or outright reversed - and at imperfectly predictable intervals, into a game it understands only a minute edge-case of.

The future. Avoiding impending doom, even. Not just dealing with the wheel slip that has already started - perhaps even PLANNED. Nor the yaw deliberately induced as part of an overall maneuver strategy.

Just how careless, clueless, or incompetent a driver does one have to be to not be able to do a far better job than DSC does?

 

I agree with you about traction control. My '96 XJ12 was pretty poor and even my '04 XJ8 intervened too much. A couple of years ago whilst driving in mildly snowy/icy conditions I went to pull away at some traffic lights and the car refused to move because the TC was cutting the engine power so I had to fumble for the TC off switch and wheel spin my way forward.

My 07 XKR on the other hand doesn't intervene enough. In the wet it is very hard to pull away rapidly without spinning the right hand rear wheel. The electronic diff of the later cars has sorted that to some extent.

With DSC though, if the system is intervening, you have either made a bad mistake or you shouldn't be driving in that manner on public roads. I have been driving cars with various forms of DSC for at least 12 years and can only remember a handful of times it has intervened and it was probably justified in doing so on those occasions. None of those occasions were in any of my Jags though so I don't agree that DSC is intrusive on those and I don't tend to hang around when I am driving either!

Jaguar's description of DSC seems a sensible safety addition in normal road use to me:

"Dynamic stability control (DSC) maximizes vehicle stability under all conditions. The DSC system compares actual vehicle course to that intended by the driver. If the intended course differs from the actual course due to over- or under-steer conditions, the DSC system will brake individual wheels and reduce engine torque to bring the vehicle back to the driver’s intended direction.

By using a combined yaw rate sensor and lateral accelerometer, the vehicles rotational motion around its vertical axis and centrifugal forces generated while cornering are calculated to determine the vehicle’s actual behavior.

Using additional sensors for detecting steering wheel position and road wheel speed enables the system to recognize the driver’s intentions."

 

Marketing buzz phrases. They haven't the least clue.

It doesn't take 'spirited' driving to expose THAT lie..

All it takes to prove the DSC has no business in the game is to traverse badly patched asphalt in an up-and-down curve exiting the same supermart the driver has been correcting for..... for twenty four years this year in a dozen other vehicles.

25 MPH zone, BTW. And I observe that. It's in my neighbourhood.

Accelerate onto the main traveled way with DSC active, throttle is decreased, left and right rear brakes produce a pronounced waggle.

Fool car lunges, dives, lunges, shakes it ****-end like a hound dog crapping chicken bones.

Turn DSC OFF, at accelerates smoothly, tracks the curve, manages the pavement breaks doesn't even chirp the tires.

Up the ante to full-throttle - same again with but a couple of small canary's worth of alternating tire chirps. Still no yaw. And no lunge/dive, either.

If DSC isn't part of the solution, then it must be part of the problem.

And it CANNOT guess intentions not yet formulated.

 

It isn't easy to visualise from your description but that sounds like overzealous traction control being provoked by the uneven surface rather than DSC. Unfortunately that is rather academic because the one switch controls it all.

The first time I experienced DSC was when I went in to a corner miles too fast. As I braked to try and slow down the rear of the car went light and started to come round. There was a sudden beeping noise and the DSC cut in to stabilise the car. The last thing you need when you are fighting to control a car is a sudden and unexpected beeping so whoever designed that should be shot because it is totally distracting but the DSC did its job!

We have so many deaths in this country where people loose control and slam in to telegraph or power poles by the side of the road. In my opinion making DSC mandatory can only be a good thing.

If you want to have a little fun you can still turn it off but in day to day driving it shouldn't need to make its presence felt.

 

Combination of the up and down, the sharp curve of a supermart exit ramp, the chronic asphalt patching due to that traffic year-on-year. But it is for sure activated. One of my most frequent trips, as I am loathe to live on canned and frozen food, so much 'testing' in any given week.
Whether I am trail-braking a rented front-drive Fiesta to outcorner an Audi Quattro in les Diablerets or was running a still nearly new late 1950's MOPAR Hemi through my native Appalachians on far worse 2-lane, or sacrificing a set of tires in oscillation braking, last increment done sideways to widen the gap, the the tail comes around where and when I make it do so. ABS I learned to appreciate - Lancia in rush hour traffic in the North of Italy, with seriously aggressive stops rippling back through a long tailback.

DSC wudda made climbing up to San Marino on freezing rain too much like work (Alfa 75, De Dion rear was golden). Nor would one want to share space with Andorra's aggressive locals on their turf and trust to pre-digested guesswork.

If DSC really does disable itself at/above 25 MPH, not such a big deal.

Your description, however makes me wonder if it is still active where it would be an even greater danger.

Taking their drink, drugs, and electronic coms away would do far more good.

The first two we all understand. FAA (re) discovered when investigating aircraft near-misses in plain view that the human evolution (or whatever) has us hard-wired to shift the focus of our eyes to 'conversational' distance - about four feet - at any time we are talking or listening.

IOW 'hands free' is no help - the pilots in question HAD headsets and boom mikes. It is the very type of activity that triggers the shift.

Naval gunners, Combat Aviators, Artillerymen already knew about this, have always trained to talk on the radio and still keep eyeball on the target, not go up-close and unfocussed.

But it does require training, and Joe or Jill Average aren't even aware of the need, nor are rulemakers that think hands-free is doing the job.

I'm not really into high speeds lo these many years now, but in metro-area US situations, one actually DOES need to scoot and git smartly for the first 25 to 45 MPH just to stay out of the way of traffic.

An XJ8-L is a rather slow vehicle in the standstill to 15 or 20 MPH region unless kicked rather hard. Even so, it doesn't really come good until around 25 MPH and up.

UK or Continental Europe - most of the 27 countries I have driven, actually, represent rather different environments vs US needs.

Just about any vehicle imported here has to have torque and low-end upgrades, top-speed downgrades to compete with the ubiquitous and over-powered Daily Driver (empty) pick-up trucks and SUV's.

T'aint 'right', efficiency-wise, nor carbon-footprint, but it ain't an ocean I can boil more than a teacupful at a time out of.

 

This has gone completely off-topic.

Anyone care to get back to discussing the 2-1 downshift? I see that one person mentioned that they have enabled it doing a reflash of the TCM. Anyone else have this experience?

In an empty parking lot:
If I put the J shifter into 2nd, and start out, wait for the 1-2 shift, then slow down to walking speed, slam the gas (all the way down through the 'Juvenile Delinquent Switch/Button) it still will not downshift. Anyone care to experiment?

 

Hi Bill,

I put my 2006 XJL in sport mode until I get up to about 50 mph or so. When I do that it's pretty quick IMHO. Granted, I'm coming off a V6 S-Type, but the XJ has a fair bit of low end.

 

Actually, I did two things at the same time - cleared the adaptations and reflashed. I don't know which one fixed it, but my guess wold be the adaptations. The transmission is supposed to "learn" the way you drive, so if the previous owner never got on the throttle hard it would explain why the gearbox learned to upshift quickly. I'd start by clearing the adaptations and go from there.

 

Acceleration is more than adequate. I just prefer greater predictability on uneven surfaces.

Use of 'Sport' mode? I'm not sure it makes a wit of difference to accel at 50 and below - or at all. Seems 'mostly' to raise upshift points (if even..) and prevent entering 6th gear.

Using the J-shifter in manual? I do that VERY rarely. Usually for better control of de-cell, or.. honestly .. just as a panacea. Not sure I'd really notice if the "S" button controlled nought but an LED - had no effect otherwise.

As to the walking-speed carpark test .. one presumes DSC disabled, else the 'puter will prevent a call for downshift. Even IF a 1-2 downshift WERE to have been called for, the upshift command should follow so soon after as to make it hard to detect w/o instrumentation. The 'puter can change to a call for 2d gear before the mechanicals have had time to respond to a 1st gear call.

After all, the torque-converter multiplication is still in the system, the differential is neither locked nor torque-sensing, so the Jag should be easily capable of breaking traction in second, if not also in third-gear, at one wheel if not both.

All of which can give rise to shock loads that are hard on components and NOT gain anything useful in acceleration anyway. That should be expected to have been programmed to a minimum, regardless of any 'self learning' capability.The ZF - good as it is at delivering wide-spectrum performance for 'normal' driving - just does not have the sort of torque and shock budget seriously rude use can impose.

Nor should it need to. A Jaguar is - or should be - more about 'balance' than any sort of drag-strip, trailer-towing, or rock-crawling optimization.

 

True, as far as it goes, but the fact remains that clearing the adaptations/reflashing changed the behavior. Putting it back to factory spec made it shift just like any other car I've ever driven.

 

S mode on my car makes a huge difference in how readily it will downshift when calling for more acceleration (especially at cruise on the highway). I noticed that when I don't use S, I have to give it much more throttle before it kicks down. It also does not prevent shifting into 6th. On the highway, if I am in S and hit the button, revs don't change. However if I'm in Normal and hit the button, it will temporarily drop to 5th, then after about 30 seconds kick back up into 6th.

I don't think I understand what you mean by the upshift command coming so soon after the downshift. If I'm going 5 mph, and I floor it, it should drop to first and stay there until it redlines or I ease up on the throttle. That would be a delta of at least 20 mph, which is far from instant.

I've never driven a car with an auto trans that would break tires loose on a downshift unless traction was very poor (rainy, crap tires, or other reasons) I've got an alleged 415 ft/lb of torque, so this car should do it, but I find that with traction control off, it only breaks loose from a dead stop or if I'm asking too much of the tires (cornering while applying too much throttle). On the other hand, I've driven low hp cars (100 hp Miata) that could easily get the tires spinning in second if I dropped the clutch. I'm sure there are some auto transmissions that could handle these forces, but I don't think anyone expects this one to.

This brings me to my point: I recently had a shop do a transmission service (fluid and pan) and I don't know what else they did, but I now have a 2>1 kickdown! I'll have to see if I can get it to do it in Normal mode in D, but tooling around a parking lot with the J-Gate in 2, I could repeatedly get it to kick to 1st with full throttle.

I'm happy!

 

[QUOTE=oilstain;

This brings me to my point: I recently had a shop do a transmission service (fluid and pan) and I don't know what else they did, but I now have a 2>1 kickdown! I'll have to see if I can get it to do it in Normal mode in D, but tooling around a parking lot with the J-Gate in 2, I could repeatedly get it to kick to 1st with full throttle.

I'm happy![/QUOTE]

I've talked to several mechanics and they all say that this is common on adaptive transmissions. The TCM learns your driving habits and sets the shift points automatically, so if you drive in a more "spirited" fashion you have a transmission that acts differently than if you drive like my grandmother. The thing is, almost everyone drives more sedately a majority of the time, so as the years and miles accumulate your "spirited" time is diluted by your "sedate" time.

It's a long term version of what happens with the average fuel mileage reading. Clear it and then go for a spirited drive and it will average around 8mpg. Clear it and get on the highway for a tank or so and it will show upper 20's mpg. Give it enough time, and it will come down to a more realistic average, and after a couple of thousand miles or so it will average out to around 18 mpg and not much you do will change that over the course of only one tank of gas.

Same thing with the transmission adaptations. Clear them and the TCM is a blank slate. Go stomp on it for a while and the transmission will be shifting like a racecar, even in normal mode. Drive it gently and you get the opposite. Eventually, the percentage of gentle driving is such that you can't overcome it by agressive driving, you need to clear the adaptations and start over. That's what happened with my 04 XJR. I bought the car with 74k miles and could NOT get a 2-1 downshift no matter what I did. I cleared the adaptations and it was a different car. Now, 9 months later, it doesn't kick down to first quite as readily as it did before, but it also has another 8,000 miles on it, most of which were accumulated without me stomping on the throttle all the time. If it get's to where it isn't shifting down again I'll try clearing the adaptations again. It's a two minute process with WDS/IDS/SDD.

 

I use Sport only for spirited driving. That way the non-Sport is what adapts to my long term habits and S is the fun one.

 

? My XJ8-L is a sedate, reasonably well-mannered, long-distance luxo cruiser. Proper 'Grand Touring' with seriously roomy rear seating, as it were.

The 'fun one' involves 4 WD, a different set of car keys, American cubic inches, and more of them, French tires and seats, and a Japanese 5 speed MANUAL transmission.



A Dodge Caravan hauls the groceries. A GMC pickup the drywall. Or 'Old Iron' machine-tools.

Horses for courses...

If I drive the XJ8-L ...or enjoy Port and a good Cigar.. more than once a week, I am simply ......cheating.

Gots to ration the good things in life, y'know....

 

So, can you post a link or DIY to clear the adaptations? Along with all the things it takes to complete the job?
I'm sure I probably need some special tool, software, or cable?

 

Any dealer can do it or buy a Mongoose JLR & use IDS/SDD.