XJ ( X351 ) 2009 - 2019

Sudden and uncontrolled acceleration

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  #21  
Old 07-06-2014, 06:24 PM
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If they can't recreate the issue, what else could they possibly do for you?
 
  #22  
Old 07-14-2014, 05:41 PM
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The story is frightening to say the least.
For the dealer to do nothing is also frightening.
The most logical thing to do is change the computer and or part for observation.
Troubling - The peddle to the floor. I have no idea how the linkage is
but a car can be rev'ed with out moving the peddle. Its not the peddle, so to speak,
It's what is telling the peddle what to do and that would be winter, dynamic buttons.
But for a dealership to take just little concern is the biggest problem.
My respect for Jag dealerships seems to get lower with post reading.
 
  #23  
Old 07-14-2014, 06:48 PM
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Sorry, but I disagree. The case was investigated by the dealer as confirmed by the OP. They provided a loaner free of charge if I read the posts correctly, which infers that the car was there for some time.

According to the OP "The pedal was physically down. I had just accelerated and when I let off the gas, it stayed down. "

No computer can cause that.

The OP also stated that the dealer couldn't recreate the problem. We have no reason to believe that they did not test the component fully looking for any sort of possible fault, given the sensationalistic overtones of 'yet another runaway car panic'. Swapping parts as part of a witch hunt may pacify owners but makes little technical sense. It also leads to leap of logic conspiracy theory rumours that 'there must have been a problem if they swapped it'.

The OP also stated that the transmission could not be shifted to neutral during the event. There is no mechanical or electrical connection between the gas pedal and the transmission that could prevent movement of the transmission lever. No further explanation was offered.

I have no doubt that the OP experienced a problem, but again ask what more the dealership (or Jag corporate) could have done?
 
  #24  
Old 07-15-2014, 02:17 AM
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The pedal has no motor so it has to be something physical such as a car mat jamming it down. It's not a computer issue judging by the facts.

Fairly easy to investigate a physical pedal assembly to check not damaged. Computers check its dual sensors for correct readings and throw codes / limp mode etc if they fail - that's not happening so it is just down to the mechanism in that assembly. As I put, easily checked.
 
  #25  
Old 07-15-2014, 05:13 AM
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This is what I was saying in around about way, but with out saying the poster did not know what he/she was talking about.
If I was the Repairman, my first reaction, impossible.
Benefit of doubt
As for floor mats - generally they would react the other way.
Like the guy who comes in and states My brakes don't work, but after the coke bottle was removed from under the peddle, they were fine.
 
  #26  
Old 07-15-2014, 08:01 PM
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Originally Posted by JagV8
The pedal has no motor so it has to be something physical such as a car mat jamming it down. It's not a computer issue judging by the facts.

Fairly easy to investigate a physical pedal assembly to check not damaged. Computers check its dual sensors for correct readings and throw codes / limp mode etc if they fail - that's not happening so it is just down to the mechanism in that assembly. As I put, easily checked.
I had a F350 diesel truck and a number of years ago and the pedal stayed down, wide open, and it was mechanical... it was the floor mat had shifted just enough to catch the tip of the pedal.. easy solution I just reached down and tugged the mat and it released...
I have never had a peddle stuck down on any modern car, and I push the pedal down all the way lots of times.. agree that the dealer and Jaguar can't do much more than check it out, assuming of course that this has never happened before with their cars or otherwise, no history.
Lawrence
 
  #27  
Old 07-16-2014, 04:34 AM
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I had this happen once to me with my old XJ6 Series 3. The mat had moved and jammed the side of the pedal. Fortunately, I was on the open highway, so just hooked my foot underneath the pedal and pulled it back up. Then I pulled in and found the problem. It was soon fixed and I never had that problem again. Lots of others of course, it was a 1980 Series 3, after all !!
 
  #28  
Old 01-16-2016, 09:52 PM
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I had similar incident happen to me today. I have a 2011 XJ that I recently purchased (3 days old). I was in dynamic mode, in drive, stopped in a drive thru with my foot on the brake placing my order and then suddenly the car starts revving and the rear wheels start spinning out, as I jammed the brakes for dear life. I quickly removed dynamic mode and then shifted into park. It then revved back down to normal. Scared the heck out of me. I too was completely shaken. I couldn't tell you if the gas pedal moved but definitely that throttle was open. I don't know if there is a throttle linkage or if it's controlled by ECM. My guess is the latter. Luckily I wasn't in traffic and no one got hurt. Will take it to the dealer. Just wanted to share this post in hopes Jaguar can address this safety issue; someone could have gotten killed.
 
  #29  
Old 01-17-2016, 12:10 AM
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Big footed distracted driver addressing the drive through window
moves foot sideways while squirming around.

Gas pedal goes down. Driver presses harder on brake upon hearing
engine revs increasing ... while foot is also over gas pedal.

Driver presses even harder on "the brake" as he panics. Gas pedal
goes down even further. Revs increase even more.
 
  #30  
Old 01-17-2016, 01:07 AM
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+1. If you inadvertently step on the right side edge of the brake pedal with the left side of your right foot, it's easy for the right side of your right foot to also make contact with the gas pedal at the same time, particularly if you pivot on your heel between the gas and the brake. It happened to me, and I wear a size 11 shoe. Fortunately, I quickly realized what I did and there was no harm done.

Fortunately, that one-time mistake was a reminder to always pick up my foot and step on the center of the brake pedal. I haven't made that mistake again.
 
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  #31  
Old 01-17-2016, 09:24 AM
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Brake should stop the car in that situation. You get revs but not acceleration.
 
  #32  
Old 01-17-2016, 09:39 AM
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Originally Posted by JagV8
Brake should stop the car in that situation. You get revs but not acceleration.
+1

Originally Posted by Patrocp
then suddenly the car starts revving and the rear wheels start spinning out,
and certainly not wheel spin.
 
  #33  
Old 01-17-2016, 09:51 AM
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Many years ago I was driving an Audi 5000 loaner car and had turned the cruise off and on 3 times or so while driving at a steady speed. The 3rd time the pedal went all the way to the floor, and would not release by touching the brake. I switched the cruise back off and the pedal returned fully. So, I experienced "unintended acceleration" first hand. The dealer said they "had never had that happen before" and would look into it. Pretty certain they could not duplicate it though.


In reading the posts regarding the Audi unintended acceleration I would say the majority of the commenters and the official factory position was that there must have been "driver error" or carpeting bunching up, or something like that in most if not all cases. So be prepared for denial or at the very least skepticism from the dealer.


I will say I fall into the camp of questioning the folks who said there was "nothing they could do" when their Toyota took off at full throttle (seriously ?).


Since the original post was back a couple of years, I wonder if the problem was ever resolved.
 

Last edited by 64vette; 01-17-2016 at 10:15 AM.
  #34  
Old 01-17-2016, 12:39 PM
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Happens to me in a MINI S too. Size 14 and edge of shoe catches pedal while breaking. Scary at track. These Jags are controlled by throttle by wire, so it is milliseconds to respond. Must be aware of foot postion on pedals.





Originally Posted by 64vette
Many years ago I was driving an Audi 5000 loaner car and had turned the cruise off and on 3 times or so while driving at a steady speed. The 3rd time the pedal went all the way to the floor, and would not release by touching the brake. I switched the cruise back off and the pedal returned fully. So, I experienced "unintended acceleration" first hand. The dealer said they "had never had that happen before" and would look into it. Pretty certain they could not duplicate it though.


In reading the posts regarding the Audi unintended acceleration I would say the majority of the commenters and the official factory position was that there must have been "driver error" or carpeting bunching up, or something like that in most if not all cases. So be prepared for denial or at the very least skepticism from the dealer.


I will say I fall into the camp of questioning the folks who said there was "nothing they could do" when their Toyota took off at full throttle (seriously ?).


Since the original post was back a couple of years, I wonder if the problem was ever resolved.
 
  #35  
Old 01-18-2016, 02:22 AM
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As I posted, brakes will stop the car. Worst case the engine revs a lot. There's an engine limiter but let's imagine it fails (never a report of it) then engine may be wrecked.

The OP managed to use the brake and engine was not wrecked.

It would seem the OP did not do much to find his original problem cause other than complain.

Overall it seems to be a non-issue or at least a non-car / non-Jaguar issue. If it happens, use the brake till stationary, then turn off the engine. Report the outcome - with details not a rant.
 
  #36  
Old 01-18-2016, 04:23 AM
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I do not know the nature of the OP problems but in the case of such an emergency, the car could have been brought to a stop by holding the stop start button in for 2 Sec or tapping it twice with in 3 sec.
This is the emergency proceedure for stopping the car when unwanted acceleration has occurred.
 
  #37  
Old 01-18-2016, 01:24 PM
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Originally Posted by MHT
I do not know the nature of the OP problems but in the case of such an emergency, the car could have been brought to a stop by holding the stop start button in for 2 Sec or tapping it twice with in 3 sec.
This is the emergency proceedure for stopping the car when unwanted acceleration has occurred.
Did not know that, thanks very much.
 
  #38  
Old 01-18-2016, 01:42 PM
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The plot thickens. I'd like to think that these two guys weren't so stupid as to mistake the gas pedal for the brake, but I also believe there could be horrible glitches in the electronic throttle system that could affect a vanishingly small number of cars. Not sure what to think!

I do think it's possible that a RWD car could light up the rear tires in the process of getting under control in an unexpected revving situation. The rear brakes are much less strong than the front brakes!
 
  #39  
Old 01-18-2016, 01:55 PM
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There's DSC or similar that prevents such wheel spin.

Go out and try it in your car. Mash the gas and brake as hard as you can while at a stop. Aside from the engine revving, nothing much happens.

I've fat footed both pedals on a few occasions, especially in winter when heavy boots are being worn, like right now in Toronto where the latest event 'occurred'
 
  #40  
Old 01-19-2016, 02:28 AM
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If you do manage (with brakes fully applied) to get wheel spin or the like, you've faulty brakes that need fixing.

No matter what the engine tries to do the brakes should always stop the car. Worst case the engine revs itself to destruction but still the brakes should stop the car. Faulty brakes if not.
 


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