For the past 10 months or so, I’ve been having the “stability control fail” message along with the ABS light. Based upon info from this forum, I believed Ihad an ABS sensor or wire harness going bad, but found no problems when I cleanedand tested the sensors, harnesses and connectors. I decided it must be the dreaded ABS module solderjoint failure, but I wasn’t too concerned about fixing right away because it’snot my daily driver. Additionally, it started and drove perfectly, without any other problems or warnings.

About a week ago, I was surprised to find that my battery had gone dead after sitting for only a week. I put my battery charger on it for a while, started it and confirmed the electrical system was charging it, then drove about 12 miles to visit somefriends. I came home after a few hours, and all seemed normal. The very next day, the battery was dead again. Off Iwent to AutoZone where they tested and confirmed my battery was bad. I got a replacement and an unexpected $25 credit since my old battery hadn’t quite reached the end of its warranty period.

All was back to normal after the installation, with the exception of the ABS issue. But after using the car a few more times, both the ABS light and the message were suddenly gone! And now, after well over100 more miles, they have not returned!

Was the battery the cause for the warning message and light being on all this time?

-John

Yes, like the window memory can be, the ABS can also be hypersensitive to a weak battery. The problem comes about during starting when the starter load draws the voltage of the weak battery down and causes electronic module malfunction.

Thanks, White. Funny thing is that it always started fine. In other words, the cranking speed during the starting process seemed normal, and I haven't noticed a difference with the new battery.

-John

It still amazes me how many different issues a weak battery can cause in these Jaguars. Had to replace the factory battery in my wife's 2006 XK8 in September 2012 after a bit more than seven months of ownership. The first sign of battery failure was the well-known issue with the windows not automatically cracking open and then closing whenever the doors are opened and closed on a ragtop model....

The factory battery in our 2005 S-Type continues to perform normally. Fairly unusual for a Jaguar that is now more than eight-and-a-half years old. But I have consistently checked the cell levels at least quarterly and topped them up with water as necessary since purchasing this car nearly five years ago. That appears to make a big difference in battery life....