had the above car in this evening with temp gauge reading in the red constantly,, (engine code AVJ)
read live data with vag-com in engine ecu and got temp of 52C which was right
read live data in instruments and got 122C, then unplugged sensor (green 4 pin) and got 114c in live data,
anyways found signal wire to instrument cluster and earthed it out nd got -100c reading in live data

then found coolant temp senor was only getting one 5v supply which is from the engine ecu, hence temp is reading correctly there,
so guess i now need a wiring diagram of instrument cluster to look up pin and supply to cts,

any help or ideas appreciated,