OK, there's been loads of posts on here lately regarding coolant temperature and gauge readings....

If you have access to a multimeter and can probe onto the back of the ECU connector whilst it's all running, measure the voltage signal the ECU sees from the coolant sensor at pin 29 (black/green on 4x4) and compare to the chart:



http://img.photobucket.com/albums/09...tempsensor.jpg