P0128 Coolant Thermostat
Help please!!! Ok so this code keeps coming up (four times in the past year) and my truck has always run very cold. The past few days it has been in the 50's and 60's and in the evenings into the 40's. That being said my truck almost never gets 195 degrees even if it is 90 degreesF my truck wont get over 185degrees. My thermostat is OEM so it opens at 195. Can anyone tell me the reason for the code? And also is it bad for my thermostat to almost never open?