Land Rover Repair: Phantom warning lights, shuttle valve, electrical failure

Question
Good morning!
Bought a '00 LR Discovery II with 145K.  Runs great, not a problem at all, except sometimes when driving there will be a chime sound 3 times and then the ABS, TC and hill descent warning light will come on.  These three will stay on until you shut off the ignition, wait about 60-90 secs. and then turn on the ignition again.  Sometimes it doesn't happen at all, other times more frequently.  No rhyme or reason.  Bought it from a LR mechanic who said that the systems are not disabled when the lights are on, just the lights.  He says he's been through everything he can think of to no avail.
Your thoughts?  and thank you in advance.

Answer
It sounds to me like an ABS modulator failure (usually a shuttle valve electrical failure).  This will store a code, as will most faults, even after the lights go out.  You need to have the vehicle scanned and these fault codes read.  You can let me know what they find.  Also, what has the LR mechanic checked out so far?