ESP, ABS and suspension lights on

[Tel19]

I have an A6 C6 2008 Allroad.  Suddenly while driving I got a long bleep and the ESP, ABS and suspension pump lights came on.  I was driving back from Spain at the time so couldn't do very much but it didn't seem to affect anything.  The ESP off switch does nothing now.  I don't know if ESP and/or ABS are working but the suspension pump is still working even though the light is on.  The only thing I have noticed different is that when using cruise control it no longer automatically brakes to maintain the set speed.  It accelerates fine but does not slow the car down on a hill.  When you first start the car sometimes there is a delay of up to 10 minutes before the lights come on and sometimes they come on immediately.  I have visually checked all the fuses for the ABS and ESP and they are fine.

I can't find any other posts which mention these 3 lights.  Has anyone any ideas?  All help appreciated, thanks.

[spartacus 68]

Scan the car with VCDS. Normally when the dash lights up like a Christmas tree it’s a wheel speed sensor.

[Magnet]

Or the ‘sender’ - often incorporated in the hub casting. 

[Tel19]

I can't get my scanner to finish the scan.  It is a VAG305 which says it is compatible with the C6.  I can't remember if I used it before on this car or an earlier model.  Just before it completes the scan I get "linking error".  I have tried all the suggested methods to get round the error but still get the same message.