Thanks for the info, but when I had the tow bar fitted I took the car for programming. The guy who did it specialises in Land Rovers and he said there was no configuration files on the car to enable him to do it, or is it in a different location? The fact that the other road lights work would support the claim that on the 2006 ff it is plug & play.

generally the lights will work anyway, does the PDC deactivate when the van is plugged in? There is nothing that can't be fixed with a hammer😜😜
FFRR 4.4 SDV8 Autobiography Santorini Black.
Fiat 500x 1.4 multiair Lounge 2015
2010 LR D4 Commercial 2.7 TDV6

Yes, rear sensors deactivate but I don't know about the front ones.

The front PDC's should remain working, I had an intermittent fault with my rear PDC and the only time it didn't give me the audible up yours, was when I had a trailer plugged in and then the front would swear at me when I got too close to something in front  Yesterday I couldn't spell Engineer... Today I are one!
Inventor of the 'Guide-o-Matic automatic wheel alignment tool'
Former long term L322 owner, Up/Down graded to a Classic Tractor!

So what should happen with the EAS? Should the lock lamp illuminate, will it just refuse to change height or will it work as normal?

On my car the lockout light comes on and I'm stuck in normal height mode, I don't know how the face lift cars respond, seeing as they are Ford 'puters not Beemer.
I know that mine will not change height at all, I've tried, and it didn't work, so I had to unplug the trailer so that I could drop the EAS, to clear a dip with the trailer. I wish that they locked the height at speed, not totally, cos when you is offroad it can be handy to adjust the height so as not to ground out the rear of the trailer, or the front when going up a hump. Yesterday I couldn't spell Engineer... Today I are one!
Inventor of the 'Guide-o-Matic automatic wheel alignment tool'
Former long term L322 owner, Up/Down graded to a Classic Tractor!