I accidentally signed up and posted my issues on the UK forum (I had wondered why it looked different, figured because I was on my cell phone). I frequent these forums quite a bit, mainly because I'm a Jag enthusiast. Also because I'm working my way up to a F-Type. As I posted in my new member post, apparently they won't let a person jump into a $100,000 vehicle without working your way up. After my 2009 XF was totaled, I figured a 2012 with the 5.0L will hold me over nicely until I get my F-Type next year. Or so I thought.

I'm going to copy/paste what I already posted in the UK forum by accident. The posts are quite long because I was trying my best to be detailed. My first post was fairly.. dramatic. As I was stranded away from home in a car I had just bought that was already displaying problems and it was 3 am and I was at some seedy hotel. It might seem like the lot owner sold be a bad car, maybe he did, but he is willing to refund me in full if I wish, he's a really great guy(seemingly), I think it's just all around bad luck. In the copy/paste that follows, the bottom comment(comment 2) is the most relevant, if additional details of what happened are needed the first comment will fill in what happened at the start.

Comment 1 C/PL:

I went searching for a new one, found the perfect one I wanted a 2012 with 30k miles at a indie dealer. It was located 300 miles away, so I drove my old backup beater there, which the dealer had found a buyer for. After completing the deal and its finally done (driving to the dealer took 2 days and was awful re: the movie Planes, trains, and automobiles) and drove off with the 2012 XF s/c, I made it not 5 miles away and I got a DSC fault and limp mode. It did flash "cruise control not available" for a split second before sticking on a DSC error message. Turning the car off and back on cured it (CEL remains on, but I know it usually takes "X" cycles with no error for it to turn off usually) but the error/limp mode would eventually come back. I called the dealer/lot owner, a real nice guy, and he about **** when I told him. I drove back and upon meeting up with him again, I told him I think it's likely a old battery and how it's a issue known to wreck electrical havoc, sure enough he said it's the original (7 years old). We got it tested at a local auto place and it came back low voltage etc. I told him "See! and you were so worried."

So he buys a battery, we install it. We drove briskly around for an hour on back roads as this is a fairly rural area. No problems at all. We get back to the lot, laugh about it giddy over it being something so simple. I tell him thanks for everything and head off.

Not 5 miles from the dealer... the car gives a tiny jolt, or lurch, and 5 seconds later I get a Cruise control not available fault (no DSC fault this time), limp mode, I pull into a lot and the car stalls. I turn the vehicle on/off and all is well again, but I call the dealer and tell him it happened again. He *****. I booked a room in a seedy hotel where I now lay on a lumpy mattress at 3 am while typing this. We're going to meet tomorrow morning and return the battery, and try putting in the (AGM?) more powerful battery with 1050 instead of 850 CCA or whatever. Then his mechanic buddy is going to show up at 8:30 to read the codes.

(The new battery ended up being bad as well. The AGM battery did the trick, at least for a few days. I mention this in comment 2)

I'm stuck without a car now 300 miles from home, stranded, as the guy that bought my old beater I used to get here is long gone.

I'm thinking wheel sensor possibly, hopefully it's just dirty. Hopefully a more powerful battery is the trick(it was.. sorta). What about it being the brake lights? I read many people fiddling with them and getting the problem to go away. I don't know if they were doing anything weird, but also I never checked. Hopefully it's not the ABS module. Another thing I noticed, the car seemed to be giving off quite a lot of heat. When working normally(between error msgs) it idles and drives incredibly smooth, very quiet. 30k miles and the car is in mint condition. But it's just, hot. After driving it hard, just hanging my arm out the window parked I could feel heat wafting, not excessive but definitely there. My old XF wasn't like this, but it was the 4.2l, perhaps the 5.0 runs hotter?

(After posting this comment, the next morning we went to a Jag mechanic the lot owner knows)


Comment 2 (reply, which I just added there):

The 2012 XF s/c I'm referring to, it truly is in excellent condition. The engine and its compartment look completely new still, as does pretty much the entire vehicle. It only has 30k miles.

So I managed to drive the car home, about a 6 hour drive because of extra traffic. Before leaving, a indy Jaguar mechanic reset everything, and did all the things a dealer would do if a battery was replaced, or so I was told. Everything seemed fine for a few days, until it finally threw a cruise control unavailable/dsc fault again. It went into limp mode, but restarting the vehicle made it go away, as usual. This time, the check engine light didn't stay on either. After the new AGM battery, the CEL goes out quickly just 1 on/off cycle, or doesn't come on at all. Before it was a given, and it would stay on even after a restart and everything seemed fine again. It took 2 hours of driving on the way home for the CEL to finally go out.

The battery and alternator have been checked a couple times now, both show fine. The odd thing now is, the car has weird idling issues. Now it will sometimes idle 20 minutes just fine. But if a error is going to happen, it always happens at very low revs like neighborhood driving, or sitting running while parked. Before the errors start to happen, the vehicle will give a little lurch, not every time but almost every time. It's not a strong lurch, really just enough to notice it happen. If it lurches and I start revving the engine, or take off from a stop sign hitting the gas a little heavier than usual, it was get past it and not going into limp mode. I haven't gotten a ABS fault which seems to usually go along with a DSC fault most times. It will either start showing a cruise control fault for a split second then settling on DSC fault, only show a DSC fault, or show no fault at all only, "restricted performance" with no check engine light. In limp mode the car idles quite rough, any other time the car is remarkably smooth, at all times. I'm having trouble being able to tell if the engine fans are spinning like they should, even with max AC. These faults never happen when the engine is cool, the engine needs to be warmed up for this to happen (I realize this only now). This has been the case every time, at least since the new AGM battery. Perhaps a weak water pump, that starts to work better with higher revs? The issue with that idea is that no code has ever signaled a water pump, or even a overheating issue of any kind. Overall I think I had 2 issues, one was the bad battery, and with that being the case, it makes the computer go crazy so none of the codes I got days ago are/were worth anything. There is also a second issue, yet unknown. I have a Jaguar specific OBD reader coming Wednesday, so no new codes until then. But since everything was wiped, any new codes now, especially after finally having a good new battery, should be very helpful.

I also have a big problem in that that I only have a few days to decide if I'm going to keep this car or not. It's low mileage and a beautiful vehicle, and it's all the right colors and features I would of chosen if I had configured it new for myself. It'd be a shame to let it go if it's only a simple problem. Last thought, after 2.5 days of finally no issues, they didn't return until it rained hard yesterday for 15 min with my car outside. Once things dried up, the issue went away. That gave me a clue, but faults happened again today with everything being bone dry so no dice there. Sorry for a long post again, but these are the only little clues I have. I will report back with any codes once I have them. I'm really at my wits end here, any help at all will be hugely appreciated.

 

On another Jag forum, a member said they had the exact same problem in every way with their 2010 XFR (5.0L), and that it ended up being the alternator and once replaced they have had no issues since. It doesn't seem common that a car with 30k miles would have a bad alternator, especially one that starts up so easily, though with these newer computerized vehicles I guess it's possible. Would a bad alternator usually show any other symptoms?

 

I can't find anywhere that says the vehicle has had Jaguar Diagnostics on it to see exactly why the CEL is illuminated?

When your code reader arrives, post the CODES for best advice.
Graham

 

Strongly suggest you return the car. No matter how nice it is, as of right now its a lemon.

It sounds like a loose ground or voltage regulator or some fuse junction box or yes the alternator. These are the symptoms of a car that sat too much. The hardest part is finding someone that knows these things well enough and brains to diagnose it, because it was designed way over complicated to seemingly go on space missions instead of duty as an ordinary sedan that it actually is. Then paying their hourly rate to infinity with no guarantee that it will actually get fixed. Let somebody else deal with it.

There are plenty others out there, its just a matter of having patience for the right one to come up for sale. Preferably one that has been driven some. Do a complete pre-purchase inspection next time at an independent specialist, before driving off. Good luck.

 

Can you call the dealer you got the car from and ask for a written extension to return the car if you can't figure it out?

Let him know you really want to keep the car but the time crunch of the return window will likely make you return it. If he can extend it a couple weeks it may give you enough time to find and fix the issue. It would be a shame to have to return the car becuase of a bad alternator or ground wire. And it's in his interest to get keep that car sold.

 

You really need to code the car out so OBD can tell you what is wrong with the car, but I'll put my money on something out of wack in your throttle control system = throttle position sensor, pedal position sensor, throttle actuator motor ect, as these play a big role in the cruise control/DSC systems which are the first faults you see before "LIMP HOME", and that lurch just before you get a fault is very telling. The kicker here is these components and many others are all considered EMISSIONS RELATED and are covered by the Federal Emissions warr for 8 years or 80kmi.
https://www.ncconsumer.org/news-arti...verlooked.html
I wouldn't tell anyone that you are privy to the Federal Emissions coverage until AFTER they diagnosed the car FIRST. Good luck!

 

Helllo XFFtype, (again) As Big Will suggest it does sound voltage related upsetting things. and could be a couple of issues confusing things.
Have you asked Jaguar for the service history, and warrantee work done, they may have been in the front of the engine, changing out water pumps and plastic CW pipes which may have upset something electrical.
Read the codes with the Jaguar code reader, after clearing and taking for a run.
With the ignition on, and engine off Floor the accelerator peddle and slowly release to recalibrate the throttle sensor, more so if the battery has been changed out, and battery removed.
Chin up. I am sure it is something simple, but a pain to find.

A good suggestion further up, requesting the extended warrantee until you can get this sorted out. and you are making progress.