Hi, I have a 2004 XJ8 (XK350) 4.2 SE petrol 58k miles, which up until last week ran perfectly. Then I hit a pot hole and my air suspension warning light came on and then went off. Eventually the fault light came on again and again and so it was diagnosed as having a weak air pump. This was replaced last week and the car drove a few miles without fault. Then I noticed a drop in power as I went round right hand bends particularly and the car went into limp mode soon after. The DSC warning light came on, then park brake warning light came on, then engine systems fault light, then restricted performance and so on. I left the car for two days and went back to it, to drive to my local jaguar specialist who repaired the air pump and I was shocked to see that the warning lights had all disappeared. So I took it for a "do or die" drive about 50 miles and it did not miss a beat!
Yesterday I took it for a short trip to the shops but it barely made it home, with all the lights going on and driving about 5 miles an hour. I suspected that even though I had given it a good run without fault, the battery was not in good health so I ordered a new battery and changed it over today. When I went to start the car, it would not start and as I say every warning light possible was on.
I called the RAC and the mechanic could not communicate with the computer and it would not allow him to clear the error or read any error codes. He could not select a gear either so he was stumped.
Your help and advice would be very much appreciated. Thanks Anthony