Help electrical problems.

Afternoon to you all, I am in need of help and advice please, L322 2004, bought cheap due to transmission problem which is all sorted, left the car for a week and no start, fit new battery and now have all the usual HDC inactive, air suspension, DSC inactive, trans-fail safe and central locking not working? Took to dealer and they want to fit; Steering lock ECU (shorted) key barrel ignition switch, steering angle sensor also ABS light on recommend replace ABS mobule (corroded) then re-check central locking after fitting ABS module, and a front ABS sensor. Starts and drives ok, compressor runs on start up,switch off front raises and lowers as if leveling, car is off the bump stops but a bit low at the rear? Done some digging but can't seem to find anything that points to which parts to start changing/testing first, dealer fix is out of the question due to costs.
So anyone of you electical gurus advise where to start or just burn it?
Sorry for the long post and any help appreciated.

Did you reset the Steering Angle Sensor by turning full lock to full lock and back to centre after refitting the battery??

If not do this, as the SaS needs to be set first before the EAS, ABS,HDC, DSC system will reset themselves!

Saint, did that but no joy, dealer wants an arm and a leg, they just want to throw parts at it so they cover themselves,5 grand for a steering column to start with!

What was the outcome of this Qatar ? I'm having similar issues and not getting any closer to resolving them

Paul, not yet resolved am back in the UK till next week on leave and trying to sort out my P38 oh the joys, I did manage to find a second hand column assembly and left car with a mate to fit and let me know if it cured any of the issues, will let you know when he gets back to me or when I get back there.

Ok, cheers. I also suspect steering column but I'm also getting that strange levelling thing from the suspension and not sure how the steering ecu would cause that but who knows

Thread resurrection and update, finally solved all issues, fitted S/H column so telescopic now working and new SAS (BMW X 5 as cheaper) reprogrammed and all good. Opened up the old SAS and one of the four contacts was worn/damaged so assume sending odd signals on a make and break contact basis.