Fuel temp sensor?????????

Has anyone replaced a fuel temp sensor on a 2004 tdi?
Can the sensor be failing and not put out a code?
What are the signs/symptoms of a failing or failing fuel temp sensor?

I have replaced mine on my 2005. If I remember correctly, if the engine and fuel are cold, and the resistance of the sensor is low, then it is bad. I believe the output is used by the ECU to retard injection timing therefore reducing power output. Mine never threw a code.

If you have VCDS you can also check when everything is cold, like after the car has been sitting overnight. Before starting the car at all, check the temp values for intake air, fuel and coolant. They should all read the same temperature. If not, the one that is far off from the others is likely bad.

I did try to measure the resistance of my FTS, but the probes on my DMM were too long to fit into the tight spaces. FWIW, I installed a 2nd sensor and left the OEM in tact but unplugged. So now the ECU is slightly fooled and my timing stays advanced, thus reducing my levels of soot based on UOA's.