I have a 2012 XF 5.0 NA just bought it used about a week a go. I noticed the braking was a bit weird compared to other cars that I have driven. When coming down to slow speeds I really noticed the non linear braking while constant pressure applied. I thought maybe it was a brake issue but then I noticed that when the engine downshifts automatically (like from 3 to 2 to 1 etc) then the cars braking force increases for that moment. I think this is due to engine braking but at the same time the rpms are so low at those speeds.

I am wondering if this is normal or if it is a transmission issue or brake issue. It is so hard to stop smoothly that I have to adjust my foot pressure in order to almost get it perfect. When coming to a complete stop it is hard to come to a stand still, instead the stopping force is sudden with a slight jerk to it.

I bought the car from a jaguar dealership certified pre-owned and they did their 100+ point inspection where the sales man told me brakes are good. I am coming up to 80,000km which is the point where its existing Platinum warranty ends (includes scheduled maintenance). I also have extended warranty so is there a problem and will it be covered?

Thanks and Regards

 

Maybe it's spelled that way in Canada but...do you mean "braking" everywhere you said "breaking" -- or is something actually breaking?

 

Yes Allenman85 - I believe that the OP meant "braking" and have adjusted the thread title to suit.
Please bear in mind that in all likelihood the native language may be French, so an easy mistake to make, I guess..


Sorry I can't help with the issue in hand though...

 

I notice that my 2010 XF downshifts while braking sometimes - I mostly notice it early on in the journey (with cold engine) when going down hills. I assumed it was a normal feature of the way the gearbox is set up - perhaps to provide some additional braking power (this happens in normal Drive mode). It doesn't do it in normal start stop traffic on the flat though.
Interested to see whether anyone has insight into this

 

LOL. Except in Ontario they speak English. Just having fun with my northern friends, eh.

 

Sorry about my spelling, English class was always my weakest although it is my native language.

Corrected the OP.

I have noticed on straight flat roads the engine down shifts while reduce speed (even in regular drive mode) but the rpm's are very low I didn't assume the car would be affected that much from the engine downshift. I will try testing some more today. Also I noticed it in both cold and hot engine temperatures.

 

Ontario does have a number of Francophones due to Canada's slightly complicated history in the early 19th Century when Upper Canada and Lower Canada were separate, then combined and then separated again.

However, the majority of Canadian Francophones are functionally bilingual except in rural Quebec.

The automatic transmission will shift down into second gear just as you come to a stop so as to be ready to accelerate away. It will only select first gear as you step down past the kick down point in the electronic accelerator pedal, or paddle shift down.

The 6 speed transmission is known to exhibit a slight thump occasionally as it selects second gear as you come to a stop. There is no remedy. On the previous 5 spd ZF this thump was objectionable enough on some cars to warrant a new torque converter/ lockup clutch being fitted. The 6 spd should not suffer this defect.

The 8 spd does not exhibit this slight thump.

 

Another possibility is transmission shift pattern adaptation by the previous owner. You could ask the dealership to cancel the adaptation so you can have the transmission ECU re-learn your personal driving style. It is a short job (pun intended) and they can check the battery condition at the same time.

 

This would be my guess too. The 'lurch' first came to light on the 2003 S-types and was never universally fixed. Mine still does it from time to time even after exhausting every know fix.

The usage of 'break' instead of 'brake' is unfortunately all too common here along with every other common homophonic error.

 

When driving in Atlanta traffic I keep the tranny in snow mode. Easy start-ups and keeps the tranny from constantly shifting back and fourth.

 

Speaking of homophones

Canada 1
USA 1

 

Yes, it is a slight thump / "lurch" where the car gives a short jump as if the transmission is not shifting smoothly into the correct rpm's for the speed. I have noticed it when driving on the highway where the car shifts from 4th to 3rd , and again then 3rd to 2nd.

I do notice it at least 2 times while slowing down. Also it does not happen occasionally for me, it is near every time. The only times I may not have noticed it is when heavy breaking from high speeds. I also noticed it while coasting (letting off the acceleration with no pressure on any pedals) where the car thumps on the downshift as it slows down.

 

Oh no!........

Canada 2
USA 1



Have you got 'sport mode' selected?

 

How did I miss that again! I guess I am just not used to writing braking/brake.

I am not in sport mode, I would expect it to be a sport mode type of feature as the shifts are aggressive but I am in regular drive.

I am planning to head to the dealer sometime maybe this weekend, what should I tell them / ask them?

 

[QUOTE=hen555;1236578]How did I miss that again! I guess I am just not used to writing braking/brake.QUOTE]


Don't worry too much about that Hen555, it's just some gentle ribbing.

We need to try and help / advise on your issues as best we can
Best
Jim

 

As you're aware internet diagnostics are difficult. The problem is sounding a bit mechanical so I would make sure the rear mount (tail of transmission) and the u-joints are inspected. Kind of hard to believe the computer could be doing this by having been taught by a previous owner.
If it's repeatable I would have a service tech ride with me instead of having the advisor just listen to your complaint.

 

Tell them exactly what you've described to us above. The harsh downshifts might be cured with a simple reflash or similar. It's quite surprising what habits the transmissions learn over time.

Edit- before slowing for a stop, try shifting to neutral. See if the harshness is still present.

 

My 2011 does the same thing, from what a few have said above this seems to be normal with the 6spd ZF.

I can also say when you put the car in neutral and coast to a stop it is smooth as silk.

You can also minimize the thump with your braking technique, if I progressively come to a stop and let off slightly before completely coming to a stop there is no thump.

See this thread
https://www.jaguarforums.com/forum/x...advice-103073/

 

Yes, and "autocorrect" as well as touch screen keyboard software make these errors all too common, including misspelling "homophones"....(perhaps fortunately the word spelled with a "n" is given priority by the software).

 

Ask them to "reset" the transmission software so that you can readapt the adaptation mode.