Not true!!!! Just google the following
Limp Home Lexus
Limp Home Beamer
Limp Home Benz
Limp Home Nissan

etc etc etc... I don't think the others are throttle body/water related, but clearly a plethora of people with other high end vehicle including myself with an E55 AMG and another late model E Class Sedan, have experienced the same problem from whatever reason(s) in the past. I have an 05 STR that got the check engine light after going through a carwash, and yesterday 4/16/2011 it rained wildly while I was on a photo shoot at the lookouts off of 395. I made it home without incident, but on Palm Sunday, I was clearly in limp mode where nothing on the car worked, parking brake fault, engine fault, limited performance max speed about 3 mph. I'll be making my dealer appointment this week and using all of the data in this forum to get my problem fixed right the first time (hopefully). I just don't want to see Jag taking the hit when all vehicles are suffering comparable problems because of new technology and improper user testing in all conditions. For the record, I got my STR used with 33,000 on it. I was shipped in from Southern California (where it almost never rains), so my guess is my car has never been subjected to the conditions here in the north east it's experienced lately.

 

Sorry to keep banging on about this, with these random error codes appearing out of nowhere, restricted performance from apparently nowhere, I make the following utterly true statement:--

I put a 68,000 microfarad capacitor (electrolytic) shunted with a 20 microfarad (mylar) capacitor across my 12volt battery some 8 months ago, and NOT ONCE have I had the restricted performance problem since. It was such a cheap fix I'm astonished that no-one here to my knowlege has at least tried it. In fact all the posters expressed scepticism.
I of course have as much power as I want all the time....lol!
Leedsman.
p.s. Along with the sealed for death autobox, I suspect the reason I got the car so cheaply when I bought it was this random restricted performance power loss.

 

And I will keep posting behind you....

1) Restricted Performance IS NOT THE SAME as Limp Mode

2) The Limp Mode issue is a known issue that has a couple of solid causes. Water intrusion into a connector on the throttle body and/or failed sensors in the throttle body or pedal.

None of these are related to battery issues...

 

Being a practical type, one cannot know definitively whether a remedy works until it's been tried out. That's how penicillin was found to work and has saved millions of lives since.
The whole point of my posting is that it's so cheap and easy, it's worth a try. Nowhere in my posting do I give any guarantees as to efficacy. These are not back and white areas, they are most certainly "grey areas" as my 50 years of fixing electronic and later microprocessor based faults in machinery has evidenced. Logical fault-finding techniques do not necessarily work for logic-controlled equipment, as some manufacturers of the world's cars have found out -- but I can't mention them here.
There is no case where I shall be deflected from my position -- no matter what.
The remedy worked for me!
Leedsman.
p.s. The header on my posting read as follows, copy&paste.

"Sorry to keep banging on about this, with these random error codes appearing out of nowhere, restricted performance from apparently nowhere, I make the following utterly true statement:--"
I can't see any mention of the expression, 'limp mode'.

 

Judging by vast numbers of posts here, yours is the only car apparently NOT to have been fixed via the normal (logical) means. It's also almost the only diesel - which has vastly different electronics etc. Your bodge may work for someone else but it doesn't look likely and I'd certainly stick to normal fault-finding and fixing before trying it.

I'd kinda like someone to try it and say "didn't work" but hey.

 

Proving a negative is by definition impossible.

Now, as far as the efficacy of fitting a capacitor, it actually fits right in line with your repeated cautions to fit a new battery.

The capacitor network has the effect of masking power sags and spikes. In other words, it cleans up the power supply. It also has the effect of ensuring that standby power at a higher float voltage is available while the computer is in sleep mode.

So, if someone has a older battery, noisy alternator, or noisy circuits, it is possible that the capacitor network will mask those causes sufficiently in threshold cases to eliminate the symptoms.

For most drivers, no symptoms = no problems.

++

 

I know how they work. They're not going to fix the actual problems cars have with the possible exception of anyone whose car has specific types of noise spikes. Only one car so far appears to be like that. I know you can't prove a negative but then I didn't ask that.

 

But this thread IS ABOUT Limp Mode... "Restricted Performance" is a totally different animal...

 

I think readers here are intelligent enough to make up their own minds about this particular subject.
Leedsman.

 

When I first visited here to look for a solution to my limp-home problem (I didnt even know the term yet), I was actually uncovering my battery looking for moisture because of your posts. I was about to try to figure out what you were talking about with capacitors and what-not, when I got better versed in the differences between Restricted Performance and Limp Mode. I also got a code reader on my car and I did realize that your solution did not fit my problem. I'm glad I didnt short out my system, I dont think that would have fixed what I have.

I happen to ALSO get the Restricted Performance issue too, but far less frequently and it comes with a different code [P0171: System too Lean (Bank 1)] and does not throw me into Limp mode [P2135, P1000, P1111].

 

The P2135 sounds like JTB00022:

JTB00022 Jan 2007 Vehicle goes into limp-home mode with DTC P2135 stored

Needs the dealer to reflash the PCM (aka ECM).

 

My 2002 X Type went into limp mode a couple of years ago, seems someone went to lean into the engine compartment and used the starter to lean on and bent the terminals till they shorted. Cost me a new starter and some grey hairs. A simple yet stupid way to put a Jag into limp mode. As far as the code thing "it comes with a different code [P0171: System too Lean (Bank 1)] and does not throw me into Limp mode " be cautious. This code sounds eerily similar to the code the mechanic says he pulled off my car.
FYI,I am a grandma recovering from back surgery, and I apologize for the length of this post. I took my 2002 X-type in two weeks ago for an oil and lube. My mechanic who I trusted has relocated an hours drive north of me, darn! The new mechanic who took his place is not honest. Let me explain. First the price of the oil and lube has
been raised $20 since my previous visit, he blamed it on Libya. Ok, then, he tells me my tie rod end is bad, I tell him I will have my son in law check on it when he returns from out of town in a few days.
The next morning my engine light came on, so I took it back to the mechanic. Now he tells me my (pulled codes) catalytic converter and both oxygen sensors are needing replaced at a cost of almost $800. I went home and broke out my old truck to drive around, not good for my back!
When my son in law got to looking at the car, pulling the codes and checking the system. He found an air intake (vaccume?)hose missing it's worm clamp and laying loose! I am not a mechanic but my dad was so I know worm screw clamps might get loose but do not just jump off. He put another one on and told me that this
alone might have triggered the engine light. He reset the code and now I am waiting for it to come back on, or not. A week later and the engine light is still dark.
Maybe I am paranoid but this sounds like I was set up for a needless repair. I am also concerned he did something else to the car, like that tie rod he wanted to ''fix''. What a jerk!
By the way I love my little jag, especially after my back surgery, it is so comfy.
I really need an honest mechanic in the Salt Lake city area if anyone knows of one, I would sure appreciate it!

 

Interesting topic and direction and I wish to subscribe to this thread.

 

Flitter 54 I'm so sorry you've had this unfortunate experience with your new mechanic; it happens here in UK too, and it does not help the reputation of some garages who one would expect to be both knowlegeable and honest, but I'm unable to comment further on that one.
Nowadays cars are machines that are electronically controlled, and this one fact makes it much easier for the unscrupulous so-called mechanic to rip you off when you quite rightly use the phrase "not honest".
Electronic control also is a handy excuse for the incompetent 'mechanic' to blame for his own deficiencies. For the semi-competent mechanic, the whole electronic diagnostic system becomes another excuse for non-thinking and proper fault-finding techniques. A lot of experience is needed, especially make-specific (partic. Jaguars) to become a competent mechanic, and you need to find one who will charge you a fair rate for a good job.
So keep searching, asking around etc. Somewhere there will be an outfit to suit your needs.
Leedsman.

 

Last weekend on Palm Sunday 04/17/2011, my car went into Limp mode after driving through some torrential rains of nearly unheard proportions here in Maryland (See previous post on the subject matter). I don't remember the codes, but I got the engine fault failure, the DSC unavailable message and the parking break message.

I have repeatedly gotten the engine fault failure light illumination every time I'd send the car through a carwash. The car was in Limp Mode on Palm Sunday Morning. It started fine, but then began to shake violently and idle a bit higher than normal. I shut it down and restarted it a few minutes later to have all messages clear. After driving about 1.3 miles, the car went back into limp home mode. I then let it sit in the warm sun until late afternoon, and all mesages had miraculously cleared themselves.

I took the vehcile to the dealership on 4/25/2011 @ 2pm and received a call on 04/26/2011 @ 3:08pm that my throttle body required replacement, a hose needs replaceing and a couple of other things. At last word, the dealership mentioned that they were contacting my extended warranty company to get clearance for the repairs.

I can tell you I have grooving on the rear disc brakes and the fuel door latch lock has become inoperable. I subscribed to Topix for the day and and reviewed the following items for my 2005 Platinum STR

jtb00188 ********** Warranty
issue 1
Date 09 Apr 2010
Section 202
Engine MIL illuminated with DTC 1254 stored
************************************************** ***
I believe the above may be an ECU re-program.

jtb00136
issue 1
Date 25 nov 2008
Section 303
Aluminum Component Thread Repair
************************************************** ****
I don't know that I'll need the one posted above but it has to do with the engine

JTB00045
issue 3
Date 29 May 2009
Drive Belt Noise - Repair Procedure
************************************************** *****
I never experienced this problem. No unwanted noise from the engine whatsoever

ST310-008
Section 310-00
Fuel Filler Door Hard to Close/Open
ST310-008
************************************************** ******
This was the fuel door issue

JTB00219
Issue 1
11 Apr 2011
Section 501
Overhead Console Lower Level Service Part Availability
************************************************** **********
I've had no problems with the above

And lastly

SSM34884
Models X350 / XJ
X351 / XJ
X150 / XK
X200 / S-TYPE
X250 / XF
Title Front & Rear Brake Disc Appearance - Grooved
Category Chassis
Last modified 21-Mar-2011 00:00:00
Symptom 301000 Service Brake System
Content
Concern:
Analysis of warranty returns on rear brake discs for the
above vehicles has shown a number of replacements for grooves
on the outer face of the braking surface.
************************************************** ************

I have a sense that there may have been more. When I get a call back from the dealership, I'll have a copy of the services to be performed faxed to me and I'll update this tread accordingly.

I just hope the work is completed by Thursday evening.

 

I solved all my fuel door latch problems! Just break off the tabs that are molded on to the inside face of the fuel door and all your troubles will be over. It is very easy to open the fuel door with your finger when you need to fuel up and no more forgetting to unlock the door before getting out of the cockpit! "Gett-er Done"

 

Ok here's the 411

The dealership got back to me today with this list of items and the associable costs.
My extended warranty covers the 2539.16 and the labor though there is a difference in the labor rate to which I'll have to pay the difference. I'm more amazed at the 2nd have of items.

I purchased this car just 60 days ago from a very reputable nationwide dealership (I'm withholding their name for the time being) and to be socked with a bill in excess of 1949 is blatent robbery I think. The 300 dollars is my deductible and I don't need the 750 right now as I'm not at 50,000 miles, not even at 40,000 yet so that number comes right out of the pool along with the coolant flush. Thoughts????

Warranty covered items:
-throttle body
-forward wishbone arms
-alignment
-fuel filler door actuator
-thermostat

total authorized for repairs above is $2539.16


Things that are not covered:
-leaking coolant hose (hose from valve to thermostat housing): 510.00 (Do need this)
-leaking brake booster o-ring: $370.00 (Do need this)
-50,000 mile service: $750.00 (Not going to pay this)
-coolant flush: $240.00 (I don't think so)
-labor difference: $79.00 (difference in the rate for their mechanics and the amount the warranty company covers)
-deductible: $300.00 (I'd have to pay this no matter)

 

My Fuel Door was covered under my extended warranty. I'll wear that out until it either frustrates them or me (if it continues to break). I thought about removing the door completely and just purchasing one that has a key and a lock to it.

 

This thread is all over the place... I think I need to "unsubscribe"

 

OK , this thread is mainly covering limp mode so unless a broken fuel door latch or a similar thing is the smoking gun to this limp mode please post a new thread about your symptoms
Thanks