Hi everyone , i recently changes my steering rack a week ago , and a week after cleaned my engine bay, suddenly my steering wheel became stiff and hard to turn , then showed an error "power steering malfunction service now" then I diagnosed it and I couldn't clear the fault , and tells me the Steering module failure , I then bought the complete steering column with the module and still gives me the same error and steering is still hard , could anyone have an idea how to repair such, as it is hard to drive 

Mechanicing by guesswork is the best way I know of wasting money. You diagnosed it and cannot clear the fault. Have you diagnosed it or just hit clear fault on the scanner? 

Didn't just cleared fault , tried calibrating it and angle sensor also but it fails to even connect to the module on the power steering, and all this after I power washed and cleaned the engine 

Cleared the fault on the scanner then tried to recalibrate but could not connect to the module. Scanners do not mend cars. You use the information they provide to make a reasoned diagnosis.  I am a long way away but  we're I forced to guess, I would start at the fuse box because you appear to have no power to the steering motor and no response to the scanner. That indicates that there is a missing power feed, so if the fuse has not blown and you disconnected the battery before starting work, then I would suspect that a connection has been dislodged. Go back and check your work.

Thanks, I've taken it to an approved auto electrician today , as I'm frustrated , will wait for the feedback 

 

I think that is a very good idea. I expect that he will find the problem quite quickly. Good luck.