Will not start

It sounds like you have a DME module that went out. To be sure, let's run a CAN scan which will tell us for sure what's going on. This guide and video will show you how. I have also included the DME module replacement instructions below to help you see what you might be in for with the repair. It is normal for the power steering to go out when the engine stops running. We should clear the codes and then turn the key on without trying to start the engine and then run the codes, these codes we need.

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

programming routine via ISTA/P:

Connect the battery charger to the vehicle.

Connect the programming system with the vehicle.

Determine the action plan.

Accept action plan with the control units to be programmed/encoded and enabled, if necessary or work through.

Observe the reworking list!

If applicable, connect the workshop system to the vehicle depending on the rework list, run the brief test and delete the fault memory.

Note:

A switch to the workshop system may not necessarily be required with the integration of the service functions and the "Delete fault memory" function in ISTA/P. Check the rework list accordingly!

The information about programming the workshop system and the corresponding notes in the user documentation must be observed.

Check out the diagrams (below). Let us know what happens and please upload pictures or videos of the problem.