Loss of power steering and ESP light on constantly

[Hannah]

Hi,
I have a Citroen DS3 2010, 1.6. And I have been trying to fix it for nearly 7 weeks but I can’t seem to find the fault. I can’t get into the ECU to reset the codes. It’s had a new battery fitted, two new front tyres, and suspension. I’ve looked into the yaw sensor and the steering wheel angle sensor (no faults with either)

I have lost my power steering and the ESP light is constantly on, I had two new tyres fitted and the mechanic allowed the car to run with the front wheels in the air which has caused this power steering and ESP issue.

The two fault codes is showing up as

U1121 - Fault no communication with the electric power steering ECU. No signal. Information from the
power steering ECU absent for more than 500 ms.
And
U1321 - Electric power steering operating fault. Reception of invalid information. Information from the power steering ECU absent for more than 500 ms.

I have tried what is suggested on the (Launch) diagnostic tool and it hasn’t worked.
Any suggestions will be appreciated.