Naweed and capsat I am obliged of your invaluable posts.
i did the hard reset and for the time being the EPS is working fine.
While the car was in workshop, I had a chance to be on mechanic's head and observe all he was doing. It wasn't the complete ECU but a portion thereof which used to drop the current output to DC motor which in turn would cause the EPS to cease working. Earlier diagnostics through the scanner also isolated the fault as interruption of current to EPS DC motor. This particular ECU has a PCB with a chipset and as such cannot be tinkered with at local level.
For those interested in the unit price its $498/- as quoted by a Japanese Spares vendor at Amayama Trading - Genuine Parts for Japan Used Imports - Amayama Trading