P0183 G81 FTS problem on a CFFB 2.0Tdi engine

The car is a VW Golf 2011 2.0tdi5K1 37X, engine code CFFB.

The engine warning light startedcoming on and VCDS came up with fault code P0183 Open or shortto plus. VCDS fault data shows that the fuel temperature is -40C when the fault occurs but because its intermittent I cant replicate that temperature when looking at VCDS measured values. The fuel temperature is always good and the supply voltage shows about 2.5v. I previously made the lazy assumption that the fuel temperature sender G81 was faulty andI replaced the part. However the problem persisted and since then I have checked the resistance at the G81 sensor terminals and it reads good at about 3.2 Kohms.

Looking at the wiring diagram,the sensor is fed by 2 wires one of which is a brown wire to earth. The earth isgood, and I have tried shaking the wires to loose the earth. However when the ignition is on the earth reading jumps from 3.7ohms to 43 ohms. I am not sure what to make of this. The other wire is a green wire which is fed from the ECUJ623, T60/42. This reads 4.9v when disconnected from the sensor and about 2.5v when connected. This I think is correct. Shaking the wires does not seem to change the readings.

The fault code clears ok but comes back after a few days.

Has anyone had this problem and can point me where to look next.
Thanks

This problem is becoming really frustrating. I notice on VCDS the frequency of the intermittent error faults are about 2 per day which is why I cant replicate the fault. I have stripped back the wiring from the G81 FTS, which is a twisted pair, about 300mm which is as much as I can do without more dismantling and cant see anything wrong.

Anyone had this problem before?
Thanks

I need to check but I think the Earth is provided by the ECU.

16567 (P0183) - Fuel Temperature Sensor A (G81): Open or Short to Plus

Easier said than done but I'd run a temporary ground to keep the diagnosis moving on. If the fault continues to flag up you can concentrate on the positive path or the ecu.

I did the same with a TTRS where a sensor ground was provided by the ECU (for what I could see as no good reason) so to prove to the customer it was the issue I just put a jumper wire from the ECU earth feed over to the earth output and it cured it. We sent the ECU to Bosch in Germany as no one in the UK would touch this particular unit and they said there was nothing wrong with it and charged me to send it back. A year later when the problem still persisted (the customer didn't like the idea of the bodge) they tested it again and said "ohh yah, der earth track ist kapt, ve can't fix it but ve can sell you ein nue vone"... the price was more than from TPS retail! I hate all ECU testing companies, charlatans all of them.

I have a diagram for my Superb 2 with CFFB engine which will probably be the same as yours.

It shows a Green wire from J623 Plug T60a Pin 42 ( Engine ECU ) to Pin 2 of the FTS plug.
Pin 1 of the FTS plug goes via a Brown wire to " 474 Sender Earth " .