Land Rover Repair: Disco 2 Air Suspension, model conversion, conversion cost

Question
The rear of my 2000 Disco TD5 has sank to its lowest and will not return to normal height. When attempting to raise the suspension by pressing the relevant button it sometimes chimes 3 times (indicating a fault) but not always. There are no warning lights displayed, other than when I press the button. Where do I start my fault diagnosis without incurring large dealership fees?

Answer
There is no backyard diagnosis for the air suspension.  You need access to one of the specialized Land Rover test systems that can talk to the SLABS computer.

If you don't want to go to the dealer there are many independent parts sellers offering kits to convert the rear suspension to coil springs, like the standard model.  Conversion cost is usually less than repair cost.