Help please. 2004 XJ8. Warning light: Engine System Fault, DTS not Available, Park Brake Fault, Check Engine. All 4 warning lights come on at the same time for no particular reason. Engine goes into a safe mode with a max of 5 miles per hour. After stopping car and waiting for no more than 2 minutes, restart car and everything is fine. Seems like it happens when I make a sharp turn or hit a bump in the road. Have already replaced one sensor and the problem still exists. My mechanic who has worked on Jags for over 30 years now believes I need a new throttle body. Any ideas or suggestions would be greatly appreciated. Thanks in advance.

 

Have you had the codes read? This collection of issues should be setting a number of DTC's.

If you have codes, post them here as it will help others to help you.

Graham

 

The initial codes were for "Random Multiple Misfires in Cylinders 1-3-5-7. As well as a code for a Throttle Sensor. That sensor was replaced but the problems continued. My mechanic tells me it was throwing off too many codes to come to an accurate assessment of the problem. He has now installed a new throttle body. Could this be it? He is not confident this is the solution. He is telling me to not pay him and drive the car and see if the problem is gone or continuing.

 

The actual codes and not just the description your mechanic has given could help in searching for further information by referencing the Jaguar DTC Listing for possible causes.

A new Throttle Body is an expensive test when he's not confident it is the source of the problem. However, he deserves great credit for not billing you if it doesn't work.

Graham

 

Battery on the way out, and also front earths (grounds) severely corroded can throw up this kind of thing. The person who located the front earths (three of them), where they are needs a red-hot poker up his ****, as they get all the road salt going.

 

Thanks for the replies to my post and dilemma. I wish I had written down all the codes my basic code reader found before I took the car to the mechanic for your additional assistance. Lesson learned. Fraser's reply has thrown me a bit. The reference to "red hot "poker" and road salt is interesting but I'm not certain it's applicable in this case. As the car has never been out of the State of Florida, it has at no time been exposed to road salt unless it's fallen off the vehicles of the Snow Birds we get thru the winter months.

 

Graham. My apologizes for my initial multiple posts. When I realized I had posted my issue in the incorrect thread I simply failed to delete them before posting in the correct area. I'm not all that experienced with using the forum postings but I will get it right next time. Love your car by the way. As an owner of a 1999 XK8 convertible for 10 years now it is my intention for my next Jag to be one similar to yours. I'll be keeping the 99.

 

You're living in permanently sunny FL, have two Jaguars already and will be going for another! I've definitely taken a wrong turn somewhere in my life.

If it turns out to be the Throttle Body, that will be the end of it except for the small matter of paying your mechanic. If it isn't the TB, the cleared codes will come back and there will be another opportunity to review them for alternative causes.

Graham

 

If I'm not mistaken, Daytona Beach is very near the sea, so you will get wind-born salt spray. Many cars run around near the sea can get quite a bit of sea salt deposited.

 

Fraser. That's a good point as to wind blown sea salt. Daytona Beach is in fact on the Atlantic Ocean and I do live on a sandbar known as a peninsula directly across the street from the beach. As sunny as Florida my be it is also an extremely rainy area with winds and rains like no get out. And, both my Jag's are garage kept. This particular area seems to have an unusually per capita Jag ownership and no one I know has ever had an issue with salt build-up of any kind. Is there any way of locating the positions of the ground contact points you made reference to in your original reply to me post other than using a red hot poker up my mechanics back side? I'm picking the car up today for it's "test" driving period to determine if the throttle body did the trick but as I drive so little it may take weeks of driving to come to a conclusion, absent the same events rearing their ugly head.

 

Hi rh99XK8

The grounds (or earths as we say in the UK), mainly subject to corrosion are fitted just behind the headlamps, one on the LH and two on the RH side. You can inspect them by removing the plastic cover just in front of the radiator and behind the grill. The aluminium corrodes and the earth connection becomes high resistance. As the electronics assume perfect earths, this can cause havoc. Mind you, if you garage your car, they may be OK, however, best to check. When I bought my car, I had read about this syndrome, so took good care to inspect and proof them with some anti-corrosion spray. I inspect them every year.

Of course this may not be the cause of your problem at all, but its cheap to check.

 

Fraser. Thanks for that information. Great advice.

 

UPDATE. Mechanic installed a used throttle body which he has warrantied 12 months, all problems seems to have vanished. I've driven the car daily now for over a week and all is well. Also installed a new TPS. Total charge was $620.23. Perfect. Suggest all in my area of Florida give my mechanic a try over dealers. Bob Sellers Jaguar Service. 386-253-4621

 

i recently had all these lights start to come on in my car also. First i checked and cleaned the front grounds behind the headlights and then sprayed them with an insulating spray.
Lights came on again so next i had the battery checked. car ran ok before and started fine but it tested bad even though it had good voltage and started the car every time. Probably just a bad cell but at least i done have a 9 yr old factory battery running may car anymore.
lights came on again so i did more research and cleaned my MAF and throttle body connectors with electrical contact cleaner.
seemed to help but engine light threw and went into restricted performance mode a couple times for a couple miles after starting car. Would turn itself off but i thought it might be bad gas so i topped off my tank with 9 gallons of E85 which has helped before in bad gas situations.
Light came on again today and all lights threw system fault mode a couple times in a drive-thru so i went and bought a can of throttle cleaner and got to work in the auto zone parking lot. the throttle plate was dirty on both sides but the inside was nasty with oil from the PCV that used to be there.
When my PCV had a crack in it earlier this year i decided to block it off and put a chrome breather cap on my head.
The throttle cleaned very easy with the product and a rag and i was able to open it with my finger and spray a liberal about of that cleaner into my intake manifold.
The car cranked over many times before it would start but when it did.....the engine light turned itself off. The car was running ok when i got there but the light was ON.
With the combination of the alcohol fuel and a newly cleaned throttle the car ran like a raped ape. I went to the gym and ran an errand afterwards and the car ran beautifully. The car is running awesome and the quickest it ever been since ownership.

 

If anyone is unsure about the earth points behind the headlamps, try undoing them. Mine looked OK, but as I undid the first one, it simply snapped off from the cross member. I have since replaced all of the front ones and all is well. A failing battery will also cause multiple faults to show up.
Les.

 

Again, thanks for all the replies to my original post. We did check the grounding posts and no change in the behavior of the vehicle. Also changed the TPS and still the same symptoms occurred. The major symptom being the car went into some sort of safe mode with a maximum speed of 5 mph, which we assume is to allow the driver to remove the car from the roadway. When we tried the replaced throttle body, all problems went away. As to a previous reply, we did also try simply cleaning the old throttle body but that did not work. There is a sensor attached to to the throttle body which we could not find available on it's own, so the replacement of the throttle body was necessary. All issues resolved. Thanks again to the members for all the suggestions and replies.