So I have been having these electrical issues with my S type diesel of 2005 and you could say from day one of picking it up (J gate blew up, only had car 2 hours).
Well the common factor has been the droplets that fall from the skies and been a person wishing to look after his transport the old wash and shampoo. So the element water has brought my car to a stand still more than once and been delivered back to Jaguar 3 times on a brake down truck.

Now they have been good picking up on a few things and have made those areas better. The car has always been back to what you think is 100% when picked up.

Now the previous time of it giving me trouble cost me £750 as the fault codes were for the throttle pedal playing up and I also changed the battery as it had been in my car from the day it left the factory and when my car has only done 64,000 miles so that battery must of been discharged a few times. So with all that done on my next return home all running well with a couple of thousand miles put on the clock and a yearly service all looking good then showing some love to my Jaguar I washed and polished it only for it to give me those dreaded words yet again and this time big time RESTRICTED PERFORMANCE and not wanting to start or run for very long.

So on with the fault reader and up came P062 (I think that was it, something with regards to low voltage) and then on the phone to Jaguar again saying its done it again. Then with the usual of disconnect the battery and check all fuses and no difference it was the call to the RAC for a visit and a brake down truck delivery to Jaguar.

Now they have been lucky with me having available other transport by my kind parents so allowing them more time to check over it again. Nice thing now is that it was playing up for them so having to push it into the workshop and when it did run it breaking down on them near the show room. Not a good advert for them pushing a broken Jaguar into a main dealers workshop. So after all the test with these computers and still no further on (throttle pedal fault code showing up again but it's got a new one already) then came the taking things apart. These cars have 2 main wiring looms one being in the engine bay and the other the being the rest of the car. So with bumper off and plastic work around the bulkhead / engine removed exposing the ecu's they did a visual inspection of the engine bay wiring loom.

Now they have taken pictures of what they have found to have been the problem which will be posted once I get home and try my car out. Problem / cause of my headaches was the wiring loom near to the ecu's had been rubbing against the chassis and had worn away the outer sheaf on 2 wires, not braking them but exposing them. Then by me washing my car or driving in wet conditions the water had then shorted the exposed wires across to the chassis. This electrical short was not enough to blow a fuse but give those lovely words on the dashboard and 3 drive homes on the back of a brake down truck.

So in the 2 and a bit years I have owned a Jaguar S type I have been on a break down truck 4 times. Now they, the Jaguar dealership say it's fixed and can find no more issues with it so my plan when I return home and pick it up will be to washer / fire a hose at it in there yard, soaking it and seeing if those words have gone. If not I'll just get a taxi home at there expense. Then it may be time for a different car and cut my losses and run but touch wood it's happy motoring from now on, but I now do have a spares kit of one throttle pedal which was never a problem (I asked for it after its removal so I could check it out) and a used but still good battery (me thinking battery voltage issues).

 

Yes, a few people have had trouble with that harness. Sorry to hear you're another. More on the UK site, e.g. by eldudereno.

 

Hi Cammy and greetings;

Yours has been a most unfortunate experience and despite not being an unknown fault, would have been a tricky diagnosis. Having said that, false flags like the throttle pedal replacement do nothing for any owners confidence ...

I have a workshop wall display of everything from ECUs and peripheral control modules, actuators, motors and other highly expensive parts that have been replaced in error or which could have been repaired and replaced at reasonable cost. I trust that one of the great benefits of these forums is to better inform and thereby minimize any lack of expertise, laziness or profit motive in the supply and fitment of parts as a result of an incorrect diagnosis.

Unlike your experience, some of these parts were swapped out for no better reason than a failing battery ... and that is unacceptable. I have been learning on these cars for 40+ years, yet all of us still get surprised by occasional thorns among the roses. I hope your car now rewards you for all your efforts and expense.
Please keep us posted,
Ken