I was driving my 2013 XJ to work this morning and in the middle of the freeway literally every warning light came on after a gear shift. I had 7 different warnings ranging from engine to transmission to brakes, but it still drove fine.

After getting to work and restarting the car only the yellow engine/emissions light was on, and it didn't show any warning messages. 8 hours later when I went to drive home no warning lights appeared, and driving it felt normal.

What do you guys think? Some kind of computer glitch? Should I take it to the dealer anyways? The nearest jaguar dealer is a bit of ways and I was hoping to avoid the trip.

I'd welcome you guys' thoughts.

 

A system voltage fluctuation will cause multiple warning lights to glow. I'd check the charging voltage and battery voltage. Odds are either the alternator or battery is failing.

 

If you have an OBDII reader inserted in the port, remove it before starting the engine.

I use an ELM327 OBDII Bluetooth reader together with an old HTC Droid Incredible phone and the free Torque app to provide virtual Water Temperature and Voltage gauges. I forgot to remove it and the next time I started the engine my dash lit up like a Christmas tree with all the warning lights flashing. I shut it off, removed the OBDII reader, restarted the engine and all was OK.

 

I didn't, but I did plug in my OBD reader and it returned a U0100 fault...which according to Google is likely a battery issue.

 

I did check it with my ODBII reader and it showed a U0100 fault, which I gather is probably a battery issue.

 

For any, ANY electrical malfunction on the modern Jaguar (locks, windows, seats, touch screen, warning lights, gearshifter not rising from the console...the list is long ) the battery is always the prime suspect - especially if the battery is 4+ years old, if the car is not driven almost daily, and/or if it is used for short runs. These cars need full battery voltage at all times to power the modules properly. The solution in these cases is to fit a battery maintainer (CTEK being the preferred brand) and using it whenever the car is garaged. The result: no issues. You can follow this on the X150 forum if in doubt.

 

Update, I took it to the dealer and it took them several days to figure out the problem. Turned out it was the rear junction box.

 

I spoke too soon, problem reappeared the day after I got the car back. Back to the dealer again lol.

 

The very first thing to do is to check your battery voltage output - on modern cars low battery voltage produces random symptoms, one of which is warning lights!
If your battery is original to the car it probably needs to be changed. And if your car is not used almost daily for trips of a decent length, investing in a permanently mounted CTEK battery maintainer will eliminate the random electrical issues. If you need corroboration of this, check the XK (X150) forum!

 

That was the first thing the dealer checked too, the battery is fine.

 

If it's done it again, read the codes.

 

When the dealer replicated the problem the codes were u0100-00, u0101-00, u0121-00, u0100-63.

 

Got it back from the dealer, they couldn't find anything wrong with it after an exhaustive diagnostic and several days of drive testing. At this point I guess we just wait and see if the problem re-occurs.

 

I saw a couple mechanics test driving a new Corvette once. The passenger's arm was broken when they flipped it in a ditch. I like to know who is going to test drive my cars.