I have a 2001 accord EX. just recently the temp gauge started acting up. at first it was fluctuating rapidly, the next day it just straight up stays on max temp soon as the car is cold started. i have checked using a scantool and the temps are staying within the recommended ranges even while going on long drives, and i hear the fans kick on and off when they should so the cooling system is definitely still functioning as it should.. anyways i've been driving the car for months like this, but i need to sell it now and with the temp gauge not working the value of the car will be MUCH less.

i've read somewhere the problem could be the guage in the dash cluster itself, but before i go hunting for parts i would like to know if someone more knowledgeable could help me out.
is there a procedure to troubleshoot where exactly the problem lies? i am somewhat capable of troubleshooting and have a multimeter, an ODB2 scanner and some tools

 

Test or just replace the gauge sending unit.