First the super V8... I know I need brakes/rotors.... Could that be the culprit? It comes on sporadically.

The XJR Has he same problem but stays on now continuously.

No codes on either

 

I had a broken ABS cable with these messages and later when the throttle body was broken. No connection with discs and pads.
TC at start up is weak battery (I see it every weekend when I take it out of garage).

 

princemarko, you say no codes. If you are using a generic reader you will not be able to display C codes. The usual culprits are dirty sensors, broken cables, and failed solder connections to the abs pump. Here is a trouble shooting guide:

http://jagrepair.com/images/AutoRepa...heet%20XK8.pdf

Please note that the resistance of the sensors is typically 1000- 1040 ohm, not 2000.

 

Disconnect the negative battery post.

Go to the ABS motor behind the left headlights. Disconnect the square connector and clean both sides, motor and connector with contact cleaner.

There is a ground stud with several eyelets secured with an acorn nut. remove the nut and clean all eyelets with contact cleaner.

Many of the circuits on these cars are sensitive to high resistance from corrosion on contacts.

 

Also, if you're going to the trouble to do what mikebaker3 suggests, make sure to either coat the connections with electrically conductive grease (e.g., Sanchem's No-Ox-Id A-Special, Volt, or others) to prevent corrosion from occurring again. If all you can get your hands on in short order is dielectric grease, connect everything up tight then apply it over the exterior of the connection.

These cars suffer from myriad "ghosts in the machine" secondary to simple electrical issues. Doing whatever you can to avoid having to revisit any connections you have already visited just makes good sense.

 

the Super V8 I'm sure is a dirty sensor since brake dust is flying out of it right now...

The XJR.... that has the abs and other warnings coming off after start and as long as i feather the brakes its ok... but if i slam on the brakes, the seem to depress and the lights come on

 

mines been on for almost 2 yrs now . don't have time to fix own car

 

@marco - the R sounds like pump solder points failing. There's plenty of posts on how to fix it.