Mate of mine has just got a 53 reg Td6 in its down to the bottom. No light on suspension dash switch, can get the compressor to run if its shorted but just exhausts and wont lift the car. Dash light still nit lit when compressor is shorted and running.
Had the machine hooked up but wont read the port and communicate any ideas guys.

The system has logged a "hard" fault, which means it has deactivated the system until the fault is cleared with a diagnostic tool.

Even if you fix the issue, it won't reset on it's own.

Poss have a hole in an airbag or the compressor is a bit weak which will cause the system to time out as it's not reached the requested height within a set time limit.

Not a major help fix wise I know, but that's where you are with the system at the moment I'm guessing..... 2011 Range Rover Vogue SE 4.4 TDV8

Previous cars :
2003 Range Rover Vogue TD6
1999 Discovery Td5 ES
1995 BMW M5 3.8 6 speed
1992 Range Rover 3.9 Efi Vogue
1992 BMW M5 3.8
1988 BMW 735i SE
1989 Ford Sierra XR4x4 2.9i
1981 Ford Fiesta Supersport

Pro diagnostic tool won't even work on the comma port works fine on my car so tool fine

I presume you have checked the fuses?
Fuse 57 15A Front passenger fuseboard.
Fuse 18 50A Rear fuseboard.
If I'm not mistaken powering up the compressor in isolation won't do anything.

Both them fuses are ok and have a live but the switch in console dead as a dodo box under the passenger seat that the header go to connections are good and not corroded like I have seen mmmmm car has stood a few months but battery is good. Starting to wonder if a mouse has been at wires LOL

As far as I can see from the wiring diagram the only things that can inhibit power to the switch panel are the two fuses above and the air suspension relay located on the rear fuseboard.

This indicates where the relay should be, I presume it's in place? Number 4.
It's always possible of course the relay is u/s. The contacts do burn eventually.

If there is a hard fault the dash switch will lock out and not operate anything until the fault has been cleared

As per my post. It won't do anything until reset. Zilch.

Computer says no.......

 2011 Range Rover Vogue SE 4.4 TDV8

Previous cars :
2003 Range Rover Vogue TD6
1999 Discovery Td5 ES
1995 BMW M5 3.8 6 speed
1992 Range Rover 3.9 Efi Vogue
1992 BMW M5 3.8
1988 BMW 735i SE
1989 Ford Sierra XR4x4 2.9i
1981 Ford Fiesta Supersport

But the com sport won't talk to the computer so cannot wipe any faults. It's a open reader that has always worked and software all up to date and license up to date on the program's so struggling. But he has found on the web that a canbus fault on headlights might cause it so is checking that today. I will keep you posted