Coolant sensor issue - Freeze Frame data pictures in thread

[TdiBlacky140]

Need some help diagnosing a coolant sensor issue, have freeze frame data and fault code below in pics.

The freeze frame data states "ETC (degrees F) = 282. I'm assuming this is the temp the engine coolant sensor is reporting? 282F converts to 138 degrees celcius, which seems way too high, so am I correct in saying that this reading is definitely wrong so faulty sensor or wiring or is this sensor just reporting the temp the gauge cluster recorded at the time as the gauge did jump to the higher end at times. The actual problem I'm having is the temp gauge behaves erratically sometimes, but is getting worse, the gauge jumps from its normal 90 degrees to the end of the scale in the red and brings on the STOP warning even though car is definitely not over-heating.

Also, sometimes the gauge can behave erratically and go the other way towards the 0 degrees mark, sometimes when I start the car from cold, the gauge can jump around a bit and the car is smokey when ideling during these start-up's, is this because the engine thinks it's colder than it is and is pumping in more fuel? But the engine is cold anyway as it's a cold start, so why smokey?

Will VCDS show the actual voltages the coolant sensor wires are getting, like a 5v signal and a signal wire voltage, or does VCDS only show the temp degrees value? Is there an output test I've heard of that shows you the actual voltage values on the wires?

This is 2.0L BKD engine btw and it has 2 coolant sensors, both are the same 2 wire sensors, 1 near the thermostat and 1 at the side of the engine above the gearbox which I've changed with a genuine new sensor and the temp gauge is still jumping to 0 or 130 from its normal 90.

Pic's below, would appreciate some feedback or ways to go about testing the wiring / sensor.

[TdiBlacky140]

I disconnected both sensors individually and together at the same time and the gauge still behaves erratically, moving from 0 - 90 -130 so I can't pinpoint which sensor is for the gauge and which is for the engine Ecu.

I thought if I disconnected 1 sensor at a time the gauge would just sit at 0 when whichever sensor that it worked off of was disconnected but seems this isn't the case.