Error Code 539 AFN: Max Speed 180, High Fuel Consumption!

Hello,
As you know, I've been the owner of a G3 variant with the AFN engine for a few days. After a drive on the highway, I was a bit disappointed with the 110 horsepower. When I got home, I immediately read the error codes and data. Everything seemed fine except for error code 539/G81, which indicates a short circuit to ground. The displayed fuel temperature was showing approximately -6°C. Would this observation explain the mediocre performance? Is the fuel density and fuel mass calculated based on the fuel temperature, which then determines the amount of fuel injected? This would at least explain my increased fuel consumption, and if it's getting too much fuel, the particulate filter system might be activated. Or, what is the fuel temperature actually used for?

Greetings.
Reuselkopp.

Hi,

It's starting off well with your AFN .

reuselkopp wrote:

So far, everything is fine except for error entry 539/ G81, which indicates a short circuit to ground. The permanently displayed fuel temperature showed approximately -6°C. Would this observation explain the moderate driving performance?

Generally, yes: Diesel fuel with a temperature of -6°C is denser than it would be at the actual temperature inside the fuel pump.
To avoid injecting apparently not too much mass , the injection volume is reduced based on the temperature-density characteristic curve.

Is the fuel volume to be injected calculated based on the fuel temperature, density, and fuel mass?

Quote:

This would at least explain my increased fuel consumption, and if it receives too much fuel, the soot reduction system would intervene.

No. If the only problem is your fault, then it shouldn't (significantly) consume more.
And the soot limit is only activated when the mass airflow sensor (MAF) value is too low for the currently desired injection amount.

Where does a TDI have a fuel scale ?