Audi q5 2.0TDI cag power steering - Vanishing power steering, the car sometimes

Hello forum users! At the beginning I write that I have probably traced the entire Internet in my case and did not find the answer to my problem. I'll get to the specifics:
AUDI Q5 2.0 TDI engine designation CAGA. Lack of good support, it works as if jumping, while driving you have to "bend" slightly to enter the corner. The car sometimes has stupid licks and enters as if in emergency mode, then the TRAKCJII lights pop up, the flashing glow plug light. ABS, and a problem with the electric manual. After these controls the car travels max 50km / h. Auto scans the computer shows me the following error;
U111300- Operation limitation due to a received message - not continuous
P065100- Open circuit B reference voltage sensor - discontinuous
P144000- Open EGR valve circuit- Discontinuous
As for power steering: There were no errors, I calibrated, the steering wheel worked for 5 km on one finger. After about 5km again the problem is that the steering wheel goes harder. Before, when replacing the timing, I immediately replaced the power steering pump, it had longitudinal clearance on the wheel. I had to hand it over for a new one so that they could regenerate it. After 2 weeks, I received a message that the pump was damaged to such an extent that it was not suitable for regeneration, a new original was installed. New oil flooded, deaerated system. Now I can't even get into the power steering controller to read the errors, I can't connect.
I am asking for some tips on where to look for a problem with assistance and where is the problem with this safe mode, is it possible for it to enter this mode through assistance, or maybe any sensor from this circuit affected by error P065100? I've already been a bit stupid. I am asking you not to send me to the mechanics, because audi has already visited everyone in the area who makes car electronics, everybody gave up. Do you have any advice for me what to bite where to look, gas pedal? "switch" from stop?
If I put the topic wrong please admins forbearing, greetings and once again I ask for advice.

Up! Any ideas or tips?

Well, if you can't connect to the power steering controller, check all the fuses and if the cables are good for the driver. You obviously have a problem with one of the drivers or can communication. Clean the egr and check the cables from it first.

The problem at that moment was solved, the support came back after cleaning the ankle and a kind of "stepper motor" in the maglownica and flooding more expensive - probably better fluid, and after intensive venting. Connection with the controller has returned, calibration is done with a finger
As for the decrease in power and this emergency mode: I replaced the air filter and clogged fuel filter (on the service tag it was clearly indicated that they were replaced about 5,000 km ago, apparently someone did not do it, unfortunately I suggested a tag, luckily for a time.) I diagnosed the problem with crowded dpf.
This is what the computer wrote to me "
Particulate filter, soot volume, 0, 170 l. The actual limit value for replacing the particle filter is: 0, 175 l, after which I dare to clog dpf. "
Car chased away at high speed on the expressway for about 15 minutes, the volume of soot dropped to 0, 150 liters.
I am a bit afraid to clean the DPF by computer and I don't believe in the effect all the time, so I don't use this method (if you can write what you think about this action)
Audi makes several hundred kilometers a month, if it is good I will let you know and I hope that maybe my post will help someone.