My '99 XK8 convertible will go into restricted performance and flash ASC upon reaching highway speeds (60-70 mph). It resumes normal performance when I switch off ASC and seems to perform responsively. The only other issue I have is, if she sits for about three days, the battery needs recharged. This started before the TB rebuild. She's got about 66,000 miles and just had TB rebuild (outstanding job by ASI). Any ideas?

 

These cars despise weak batteries and will throw all sorts of spurious codes and messages once the battery begins to fail. First things first - sounds like you need a new battery....

 

put a battery in it. That prob will fix the issues. I have to pause and wonder if the TB rebld was needed is you have such a weak battery?

 

I kind of thought the battery might be the main issue. I had read some other threads re: unrelated codes and my any people blamed the battery. I'll get it checked out ASAP.

 

Except for the issues I listed, the car has run remarkably well since the rebuild, before it would go into limp home mode about every 10 miles. But, I will be getting a new battery this week. Thanks.