I have never owned a car with this feature till my 03 XK8. Mine works fine, etc. Just curious what the failure rate is on this system, XK* specific and what happens when it stops, the lights just say where there where when it stopped working?

 

I recall very few reports of failures being posted so probably more reliable than you expect. The system is controlled by a combined Ballast/Levelling Module.

I never had any issues with the same system on my 2005MY.

Graham

 

This system continues to work properly on my wife's 2006 XK8, now nearing 100,000 miles. It appears to be made with better materials than the self-leveling headlamps in Jaguar's S-Type models (which are infamous for failure due to their lousy plastic parts). I'm very glad that my 2005 S-Type 3.0 does not have this system....

 

what happens if it craps out, goes to a default setting or sticks where ever it is at the crap put moment.

 

From the Jaguar 2003 Service Training Guide:

The sensors send a PWM signal to the headlamps and they react according to that input.
When the ignition switch is turned to the ON position, the lamps go through an initialization cycle, which consists of the lamps moving to the most downward position and then moving to the driving position. If any faults are detected the lamps will retreat into a "home" position which is the most downward position.
If the front sensor goes faulty/disconnected the system may operate in a de-rated mode, while failure of the rear sensor makes the system go into a faulty/disconnected mode and the system does go to the "home" position.

 

that makes no sense, if the system craps it does not go to a default normal position for Normal jags.

 

The S-Type ones are pretty rubbish and fail downwards - presumably to avoid dazzling others - so these ones may well do the same.

 

Mmm. Not much doubt there?