MB socket box

[m11nch]

Hi I'm trying to diagnose a gl320
x164 suspension air compressor and the star machine says

Turn off ignition
Connect to socket box
Switch on ignition.
F2 to continue

-(2.39) 73 -V+ 50 (2.16)

Any ideas

Thanks

 

[OneForTheRoad]

https://www.google.co.uk/search?q=1...=aK2OWfrsF8nfgAaShKyQBQ#imgrc=MRr4st2qnQeIBM:

 

[m11nch]

At $2500 It looks like I either goto an Indy or look at a different way to diagnose this problem

https://www.google.co.uk/search?q=1...=aK2OWfrsF8nfgAaShKyQBQ#imgrc=MRr4st2qnQeIBM: