Have had an issue today with engine failsafe mode came on intermittent then losing pedal all together stoped car re started pedal came back rev to 1000rpm warning back again last resort was a can of wd 40 as we were 40 miles from base sprayed all the sensors including pedal itself let it it stand for 45 mins started and drove 25 miles no problem overtakeing a truck not under heavy load warning came back 3 mins later lost pedal again stoped for five mins restarted drove of in 4th then changed to drive all ok turned on cruise all ok for next 20 or so miles in fact it seems fine now have stoped started about 6 times since last issue over 2 hrs ago. Pedal felt a bit slugish earlier now seems better car had been standing for 8 weeks with no use prior with low fuel range of 4 miles the other thing noted is a squek from throttle pedal when depressed am thinking that pedal would be better replaced Has anyone else experienced this issue. i wiil be montering this for the next couple of days to see if issue returns or damp had got in sensors due to our lovely wet weather in the uk

 

Do you have any codes when the OBD port is accessed?

How old is the battery in the car? Many of the codes and electrical 'faults' listed in this forum are corrected when the battery is replaced.

 

No codes read as yet i only do that as a last resort i am very much hands a hands on thinker the battery is ok replaced by previous owner about august i buy and sell these . Car was fine until it was parked up and left for eigth weeks have had an issue like this with another s type but not quite the same when left standing with a near empty tank that cleared itself with an italian tune up this a different issue has it is pointing at at the throttle pedal either faulty or lacking in lubrication and dirty terminals micro processor over heating possible cause due to dust it felt very hot prior to wd 40 spray the time it went down before last now its just luke warm now and seems more responsive to the foot as stated its fine when cruise control is engaged and currently seems fine under normal driving conditions will see over next couple of days thanks very much for your input i agree sometimes battery can be the culprit .

 

It is very difficult to offer any kind of assistance without knowing what, if any, OBD codes are stored in the system.

Knowing the codes is usually the first step in diagnosis rather than merely guessing or worse yet, throwing parts at the car in attempt to become lucky with a repair.

 

You can't tell some people, though. They see a car as non-computerised. Wrongly, but hey.

 

Be careful here.

I have the same problem on my 2000 4l S Type. I read the codes (they only pop up sometimes when it does this) and got P1584.
I made a call to get a price for a throttle body and was told it could be the pedal. I changed the pedal and it was perfect for 2 weeks and then started going into failsafe engine mode again. Thinking I'd bought a dodgy pedal, I bought another one and fitted that. Two days later, same problem.
I reckon I may need a TB now.

The reason I posted this is to serve as a warning when jumping to the conclusion that it's the pedal. I'm not saying it's not, but it doesn't seem to be the case on mine.

Thanks
Mike.

 

P1584 is in the codes PDF, free download on here. It does not relate to the pedals.

 

Amazing what WD 40 can achieve along with 2 tank fulls of shell v power have just completed 550 mile round trip without an hiccup Carlisle and back Pedal feels smoother and more responsive so put this one down to dirty fuel or dampness after standing for 8 weeks and having faith in Jaguar by the way this one is a w reg 2000 not 03 plate Mileage 109500 full history .Many thanks for your input

 

I've sprayed all the connections on the TB with WD40 and drove 6 miles home from work with no problems. A massive contrast to yesterday where I drove home jumping in and out of engine failsafe all the way home, and the same on the way in today.

Could a dowsing of WD40 have sorted my problem. I doubt it, but time will tell.

Thanks
Mike.

 

There is no way that squirting WD 40 on an electronic throttle body will fix it. However, go ahead and try some Marvel's Mystery Oil, that might help.


Unbelievable...

 

I just thought that if the fault was a dry or dirty connection, the the WD40 might help. I in no way thought it would fix anything other than that.

As it turns out, I got all the way home last night with no fault and then this morning, it happened again.

Time for a TB I reckon.

Thanks
Mike.

 

Might be a bad connector? Or a chafed wire? WD40 would at most be a temprary workaround but might have helped.

 

not on the throttle body maybe, but on/into the connectors ... definitely.

Unbelievable ...

 

Is there not a known problem on LHD S-Types where the water comes in at the base of the windshield and floods onto the connectors in the area?

 

You all may think i am bull shiting the bit i did not ad was I sprayed wd 40 over the outside of all connecters that were accessible also disconnected battery for 30 mins with the throttle body and pedal i disconnected them then used 3 in one oil and sprayed it inside the male and female connectors with the pedal i took it off and gave it a good spray so far have covered 1000 miles as i use the car for my work no problems i have also checked for codes none apparent car is ruining smoother . I also had a 99 v plate with same issue 2 years ago did the same then that covered 20.000 miles no problems have still got the car just needs lower front ball joints parked in a garage ran to mot testing station 2 wks ago no problems at all sometimes just sometimes something as simple as what i have done can cure a lot my old Dad rip who was Italian was a ferrari mechanic many moons ago used 3-1oil and wd 40 for many fixes bless him Will keep you all posted if it comes back and will eat the coil packs .Many thanks again

 

I had the same problem to start with read my last post its worth a try

 

Only for those where the seal has failed AND which have the TB at the rear (as STRs do).

There are other things at the rear, some depending on model, and the fix in all cases is to repair the seal. (Some coils are rearwards though they have other seals which also can fail.)

However, there are ways for water to get into a front-mounted (most cars) TB's connector and both the water source should be removed (e.g. nozzles resealed) and the connector too (dielectric grease and some have used silicone sealant outside the connector).

I read that WD40 was used and worked temporarily so my comments above look the way to properly fix it.

 

I'm on my third pedal, so I'm assuming it's not that so I've now ordered a throttle body and I'll change that once it arrives.

Strange thing is, I don't seem to get the same result twice. On Tuesday, I travelled to work with failsafe mode on for most of the trip. On the way home nothing. On the way in yesterday, it came on once. Again, on the way home, nothing. Then last night, I travelled about 20 miles with 3 stop offs and nothing. Today on the way in, it came on just as I arrived, which is 6 miles.

I've sprayed both pedal and TB connections with WD40.

Very strange.

Thanks
Mike

 

Today my new (second hand) throttle body arrived and I'll be fitting it tomorrow.

Let's hope that puts an end to the dreaded failsafe mode.

Fingers crossed.

Thanks
Mike.

 

So, throttle body has been fitted. So far so good, but I've been at this point before.

Let's see if it stands the test of time.

Was a simple easy job though.

Thanks
Mike.