L322 Hard Fault EAS/Can Bus Error

[t20bigjim]

Right, can someone maybe list the components that may cause a hard fault to develop?

My diagnostics keep bringing up a Air Suspension CAN error, it can’t communicate with the EAS ECU and the steering angle sensor circuit fault code comes up too. The steering angle sensor I have reset and checked with graphing on my diagnostics tool and it produces a steady signal in both directions, so why would I be getting this fault?

 

[Saint.V8]

I'd be checking the ABS ECU.....

 

[t20bigjim]

I'd be checking the ABS ECU.....

How does one check it? The ABS appears to be functioning perfectly well. Nothing in the diagnostics to say otherwise. I did ironically remove the main plug from it earlier amongst many other check of fuses etc. Now when I turn the ignition on I can hear the air suspension compressor running for a few seconds and the it switches off! I presume it’s supposed to do this to ‘precharge’ the system?

 

[t20bigjim]

Had it to a local specialist today. He can’t communicate with the EAS ECU either. Suggest maybe checking the wiring and printed off the diagrams for me. I’ve ordered a second hand EAS ECU to have a go with. I cannot for the life of me find the headlight levelling module. It is not behind the passenger side trim. My car has it according to the workshop manual as I’m in the VIN range it lists.