Hello, all.

I have an 03 XJ8 SE 4.2L with 195k miles on the clock. I have done all but 900 of the miles, and they have been mostly done on the motorways/highways of the UK. Until this year, the car has been almost faultless, and I have spent the grand total of £13,600 ($20,800) on repairs/servicing excluding tyres in 9 years. I did main dealer for everything for about 6 years, then got a local chap. Not a bad cost of ownership for our 2003-2009 XJ, eh?

This year there have been a number of warning lights flashing up with daily regularity: DSC, Gearbox and ABS.

I had the gearbox oil changed 5,000 miles ago, and the trio of problems relating to the gearbox (clunking on intial engaging of the gear lever / slipping out of gear / refusal to enter top gear), appear to have almost stopped. There have been two instances of the trio since the oil change.

I had a gearbox go in a much less expensive manual/stick shift car about ten years ago, and the top gear burned out, following a period of loud whining. It was compeletely obvious what was going on and there was no respite. The Jag gearbox faults seem altogether more mysterious, almost not like a mechanical fault, and appear and disappear seemingly at random.

The other lights that come up with regularity: ABS, DCS don't appear to have any effect on the driving - no limp-home or anything. Sometimes they come on; sometimes they dont. I cant work out any causality with the weather, the temperature or anything; like the gearbox, they seem completely random.

These are the fault codes that my mechanic got off the computer: P0730, P0720, P0701; DSC/ABS C1236, C114? ; Other P0701, P1582, 8105?

So my questions, guys:

1) What is likely to happen to the gearbox?
2) What can I do to get rid of the DCS/ABS fault lights.

Thank you.

Mikey

 

I have been getting a lot of random faults on my tranny as well, they found the valve body plug is leaking through the pins themselves shorting out various lines and causing the random faults. I am trying to find out if the plug can be repaired

 

I, too, have similar issues on my 04 with 117k. My ABS fault was due to a sensor on the right front wheel. It would get wet, the ABS would go on, then out once all was dry. All has been good since replacement.
The engine light seems to light every 500 - 700 miles. I believe this is due to a failure to reset the oil change mileage timer at my last NON-Dealer oil change. Just a guess on my part.
The gearbox fault comes on more frequently lately. I can continue to motor in the same gear without issues. As I am required to slow down and the gears reduce, I can not engage a higher gear. If I stop, turn off the car, and simply restart, all is well until the next occurrence. I've read good and bad on the gearbox fluid and filter change.
I look forward to future comments on this thread.

 

The X350's do not have an oil change mileage timer.

Sounds like time to get the car to a dealer to get the codes read and the problems properly diagnosed. If it were my car, I would be having the engine and gearbox faults diagnosed and repaired right away, as the costs of repair could be increasing the longer you drive the car with the problems.

 

You have quite a high mileage car now. As I understand it, you can get fault codes thrown up due to wear in the gearbox. This is not abnormal wear, but it causes changes in various line pressures in the box,m and this is picked up by the fault watchdog. So it would appear to be time for a gearbox re-flash to reset the system around the current state of the gearbox, i.e re-set to account for the wear. 195k is quite a big mileage, so you've done well. Eventually, one or more of the electric valves that switch the fluid around gets too worn for a re-flash to work, so it's then time for some tranny work to replace them.

 

ABS/DSC fault will be a wheel sensor or associated circuitry.

 

Could also be a dying battery....