On my way to work, cruise on, 70MPH, all of a sudden the car starts slowing down, the orange engine light and red and orange lights on the dash come on and in the driver information center I get DSC fault, engine failure, parking brake failure, restricted performance, low engine coolant and a whole host of other messages that my shocked mind didn't assimilate. I pulled over to the side, and the car wouldn't rev, but when I put it in park it was holding about 2K RPM, without my feet on the accelerator! After thinking for a few seconds, I switched off the engine for ~20 seconds and restarted. All the faults cleared and the car drove the last 6 miles to work just like nothing had happened.

My first inclination is the battery. It is dated Nov 2003 ('04 XJ8) and although it tested out fine on the last scheduled service, it is well due for replacement. In contrast my wife's '05 Durango is now on it's third battery, the first lasted one month outside of the warranty and the second lasted 2 years 11 months & 1 day (so I got a free replacement!).

Any other thoughts on what the problem could be? I'm going to take it to the dealer to see if they can pull codes but my recollection is a whole host of mystery errors seems to point to a failing battery.

- Tim

 

The same thing happened to my mother when she ran the coolant low, it shut her down into restricted performance. Did you at least confirm that was not the case?

 

No, I'll check that but there were so many messages that seem unrelated. But I'll take a peek later.

- Tim

 

Sorry to hear this. It sounds like a throttle body. This happened to me (about 6 times over several months). I tried a new battery and some other things in hopes I could avoid the inevitable. Finally replaced the throttle body and that fixed it. Others have had the same problem unfortunately. Example

 

Better Example...

 

Took the car to the Dealer on Friday. No codes so hopefully not the throttle body. Battery tested bad. I'm planning on getting a new battery. The old one did 6 years 5 months. A repalcement one from the dealer is $150 for a non-jaguar one with 2 years warranty or $200 for a Jaguar one with 18 months warranty. I can get one from Autozone (Duralast Gold) for $150 with a 3 year warranty. Any experience or recommendations?

- Tim

 

Tim,
Do follow up and let us know if this solved the problem for good and all.

 

Tim, I put a Duralast Gold in mine... even had the same side vent as the previous interstate battery...which was 2x its price.

 

Sounds like throttle body. Same thing happened to me in my old '04. Took it to the mechanic and they couldnt find any codes. I had to wait for it to happen again (which took another week) and I somehow made back to the mechanic with the lights still on. Only then could they diagnose the problem. Before that I had changed the battery to no avail. The whole experience was a real pain in the *** and almost turned me off to Jaguars.

 

Mine had the faults mostly non related to each other.
Diagnosed as battery and replaced under warranty, which cured the problem.
Struggling to see how a throttle body fault would bring up low coolant fault,park brake fault and low washer fluid...unlike a failing battery which can bring up some all the above and some faults youve probably never even heard off