I've pulled them apart and its a pretty tricky one...If it is reading WRONG, I would first suspect its probably the sensor, but if its turning off entirely you could give resoldering it a shot. There are 2/4 small screws depending on the model as they changed its design a few times and it pops right open in your hand.

I cannot stress how careful you NEED to handle the LCD with though. It will crack or leak VERY easily so handle with the utmost care. Trust me I have gone through about 3 that I found at the junkyard, put it in my pocket and next thing I knew I came to pay and it was leaking color.

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2016 Monsoon Gray Audi Allroad - 21k
2008 Black Mercedes E350 4Matic Sport - 131k
2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k