|I think your car has two temperature sensors, one for the ECU and the other for the gauge.|
What?? He has a 2001 model, not a 1951 model. The sensor is for the ECU, and the ECU in turn sends a signal to the gauge. The gauge in these cars is really just a fancy idiot light. As long as the temp is in the normal range, the gauge reads 190*.
Go to tdiparts.com or worldimpex.com and order a new temp sensor. It's located on the driver side of the block in the coolant flange. It's a 10 minute job to replace. Get a jug of G12 coolant to top off with.