The dreaded 16500 fault code

[Hans]

Hi all,

I seem to have come up with fault code "16500 engine coolant temp sensor (G62) implausible signal" on my Polo Gti.

Took it back to the dealer where I've just bought it. He gave it to his mechanic to fix. The mechanic "replaced the temp sensor and the thermostat".

Two days later, the fault code is back. This has me wondering:

Which sensors does the ECU cross-check to determine if it has a viable reading?

Is it G62 and G83?

Also, I ran a graph of the G62 output with Intake Air Temp as a baseline at the start of it, the sensor seems healthy.

Thanks in advance for any input.