A6 C6 2.7tdi CANA before turbo temperature input

[Gregp]

Afternoon all,

I'm doing some trouble shooting on my 2011 A6, C6, 2.7tdi - CANA engine code.

On my diagnostics and that of an Audi independent the temperature before turbo is measuring 849°C, but there is no sensor before the turbo on the 2.7tdi (there is on the 3.0 tdi).

Can anyone point out if this temperature is irrelevant / red herring or is the reading is calculated from another sensor or a resistor somewhere?

I have replaced the temperature sensor on the EGR cooler to rule this out but no change there.

The reason for looking into this was over the last 2 years the car has had DPF regeneration issues, resulting in me having the DPF professionally cleaned at Home - DPF Clean Team, EGR cooler cleaned by myself - a real pain to remove, injectors removed and tested (all ok) as well as other unrelated exhaust temperature sensor failures.

Any advice greatly appreciated on where this temperature input comes. Thanks a lot.