I just had a taste of what the Toyota owners are dealing with. While stopping at an intersection, my 2005 XJ8L started accelerating. Fortunately, I was only going 10 mph and the brakes were able to stop the car. Then the engine returned to idle. Just prior to this, the cruise control was acting weird. After running on cruise for a few miles, I pressed the "Cancel" button and nothing happened. The cruise would not cut off until I hit the brake. The dash display responded with the normal "Cruise Canceled" message. The sudden acceleration happened at the next intersection, and after that the cruise would not engage. Is this a cruise module or an accelerator sensor issue?

 

There are a number of related circuits associated with the drive by wire- cruise control, all the way to the abs, wheel sensors, brake light switch. The ECU is at the heart of it. There is no real practical way of diagnosing something like this online and encourage a visit to a dealer. Too much to lose with an acceleration fault.

Best,

 

Thanks Steve,
I have already made an appointment.
Glen

 

let us know if you find anything out Glen, that's the first i've heard of that happening, it would be nice to document any updates, dealer diagnostics, 'fixes', etc.

 

OK, here's an update. I took the XJ8L to the local dealership for the sudden acceleration as well as an intermittent failure of the cruise control. The tech took the car on a test ride and could not reproduce either failures. He suggested the sudden acceleration was due to the transmission downshifting during stopping and recommended a flashing of TCM. I agreed to the flashing which took about three hours including an initial "training" of the transmission with a controlled drive. During the drive the cruise control finally failed for the tech. In any event, the sudden acceleration has not happened since the reflashing. I am now waiting for the replacement cruise control switch module. The reflashing of the TCM cost $200.

 

Interesting - Thanks Glenjust. Call me old, but I'm really not a fan of throttle by wire. I still like the old solid cable connection to my gas pedal.

 

Ive had this happen to me on jags and everytime it was a fat foot. Some of the cars with adjustable pedals are adjusted in such a way that when you push on the brake, the right side of my foot would hit the gas pedal and the harder i pushed on the brake, the faster the car went. Was very unerving till i realized what i was doing. And ive done this without adjustable pedals too.....just a fyi

 

I've done the same thing when wearing my "big" boots; there's not a lot of clearance between the two pedals.

 

I agree, Norisan, that the most likely cause of the sudden acceleration is WFS (wide foot syndrome). I was able to duplicate the symptom by depressing both pedals a couple of times. For a while I was driving using both feet to avoid catching the accelerator with my right foot but have since repositioned my right heel a couple inches to the left. But it was still nice to have Jaguar check out the systems and find nothing wrong.

 

I agree, Brutal, that the most likely cause of the sudden acceleration is WFS (wide foot syndrome). I was able to duplicate the symptom by depressing both pedals a couple of times. For a while I was driving using both feet to avoid catching the accelerator with my right foot but have since repositioned my right heel a couple inches to the left. But it was still nice to have Jaguar check out the systems and find nothing wrong.

 

Good that you are satisfied, and Jaguar found nothing wrong with circuits. Drive by wire makes me nervous...especially when I am driving directly in front of a Toyota.

 

Last Friday (August 6, 2010) my 2004 xjr accelerated while I was braking to slow around a corner. Less than five minutes later, as I approached a 4 way stop intersection, the car again accelerated while braking, I had to stand on the brake pedal while the rear wheels screamed, I put the car in park and turned it off. The car is now at the dealership. I have requested that the car’s pc data be saved for me. I have enjoyed this car, the only problem I have had with it has been the alarm going off from time to time. My issue now is trusting the car, whether or not it can be fixed. The car has an extended warrantee.
Has this happen to anyone else ?
Can anyone advise me on what the manufacturer will do for me, should I not trust the car ?
What governement agency do I imform of this safety issue.

 

you didnt read the thread did you? Especially posts 7,8,9,10
go pic up your car at the dealer, and start enjoying it again without worry, and quit sidesteping the brake pedal cause thats what youre doing especially your statement about the "back tires screeming while i was pushing the brake"

 

You're are wrong on all counts.
And I would appreciate responsible replies which address my situation.

 

It was an experianced response, i meen its not like i havent worked on these for 13 years at the dealer and done the same thing myself.
See when you say things like "I was braking for a corner", and "Iwas standing on the brakes while the rear tires were screaming"
Ill say what I said and still stand behind it. I would bet money that if you had taken your foot away from the gas pedal/brake area, it would have quit accelerating... All issues Ive ever heard about on unitended accels with Jaguar and an accident(flight recorder will record with impact both before and after from things like air bag deployment, stall, inertia switch activation and a couple other instances) the flight recorder showed brakes being applied(brake pressure sensor and pedal switch) along with the gas pedal, by reading the pedal position sensor(not the throttle body position sensor, but the 1 that actually shows what your foot is doing) And it showed that before impact the gas pedal was being pushed even more than initially which goes along with someone saying "I just pushed harder and harder on the brakes and the car accelerated even more!"
good luck

 

Jagownertoo, I have heard of this problem before actually, while researching the X350 model before purchasing. The car would suddenly lurch forward from standstill and the driver would have to either put the car in Park, or shut it off completely. I believe it was more common in the 04 models. If you search google I'll believe you'll find a few similar cases. Try searching the consumer reports or consumer recalls...I can't remember exactly where I saw it.

Don't be dismayed by some of the people on this forum. Ive been alive for 25 years, but it doesnt mean I'm an expert on life. 13 years certainly is a good amount of time, considering the X350 model is only 6-7 years old.

 

Brutal's replies can be BRUTAL! I have been there after my first post! but I think he's right.

 

Thx for your help, and please explain X350, as I am not familiar with this model.
I can understand how “Brutal” could misconstrue my comments as anyone viewing the photo he posted could expect that the 4x4 (pictured in his reply) rolled over under its own power or bottomed out if winched upward onto the rock. I do not feel the need to express my experience with autos, but only to say that I’m sixty-two years old and the days of outrunning LAPD and everyone else on Mulholland Drive and in the canyons for a short period in the late sixties are far behind me. But if you were there, I ran (Rick’s) set-up red Sunbeam and Jerry’s 305 Honda punched out to 337 with 12k rpm cams, 650 Triumph carbs on 4 inch stacks and tuned megaphones (3rd fastest Honda in CA at the time).

So please allow me to better explain the subject event.

Last Friday after a long lunch at the Lodge, I was driving on a well paved road in Pebble Beach at approximately 35 mph and lightly applied the brake (only) around a curve and the car lurched (eg, vigorously accelerated). I was startled and let the car coast for a few feet, there was no traffic on Pebble Beach Drive at the moment. I resumed the drive home, and I was very much alert and aware and very careful, I applied the brakes several times without incident and stopped at one stop sign before I approached the second stop sign. Five plus minutes later, as I neared a 4 way stop intersection, I slowly I applied the brakes a normal distance before the intersection, but as I was attempting to stop the car before the intersection, the car lurch forward and I instantly stood on the brake pedal (only) and moved the shifter into the Park position and turned the key off. I was about five feet farther into the intersection than I planned. The car on my left did not move into the intersection as he observed the event (and gave me his phone #), he heard my wheels screech (for a split second) and maybe my front wheels made noise too, I only recall hearing the rear wheels.

So gentlemen, I do appreciate any info relating to this kind of event. Thx again.

 

Scrapped the bumper, not bottomed out, and ive never had to winch it up or down anything(yet) that was in moab in may.
But thanks for the aknowledgement. You know you didnt give alot of info the first time around, and if you also read the sig you noticed i dont have crystal ball so i have "no idea" what your car experiance is. What i related was experiance. And im only a decade behind you and experianced racers myself(never ran mulholland though, but did drive down it at normal speeds, sort of, in a rent car 1 time)
at least you know how to put a car in park or nuetral unlike the "prius" owner. But as i said before, there was no event and the flight recorder wont record a non event(air bag deployment etc..)
i still stand behind my presumption though wether correct or not just based on what ive seen, heard and done myself over the years
Are you sure you werent "Heel and toeing the pedal and brake" like any good canyon racer would. I meen if you were doing that in the
60's.....maybe you were having a flashback
all the above is pretty true, has got lots of(BRUTAL, my) humor in it. So dont get all bent on me and take anything the wrong way

 

thx.......and no problem......no bends here.......I'm just looking for others with a similar experience……..and no again, I didn’t toe’n’heel it…………and back in the day when one could getaway with a committed run on the streets..…….I didn’t toe’n’heel then either………cuz I never had enough horse power in any of my vehicles. My technique was right foot hard pressed against the gas pedal all times in the top of second or third and braking with left foot as needed……..I changed-out a lot of brakes pads, sometimes after just one run, if it was hard, but it was doable for me cuz I worked the graveyard shift at the Standard Station on Canon and Little Santa Monica in Beverly Hills while going to college during the day. Even with the Toyota frauds out there, I think it strange that someone familiar with the complicated electrics in vehicles of today, would deny an eyewitness account…….not the less…..I will not drive the subject jag again, I neither trust the car nor the replacement equipment and I don’t have confidence in the service department, I know none of them…….buy hey, maybe you want the car.