2004 GMC 2500hd Duramax with engine code P0118. Is the problem sensor or thermostat?

Question

My problem involves a 2004 gmc 2500hd. My engine light went on and my engine coolant temperature gauge stopped working. The scanner code that came up is p0118. Is the problem sensor or thermostat?

Answer 1

Hi there,

Most often the sensor itself is the issue. If the truck isn't showing any signs of overheating, then replacing the ECT will generally get your gauge working again. It is possible if the thermostat is stuck open you could have this issue. A simple test is to make sure you have heat. If you don't have hot air, then the engine is running cold and the Tstat is the problem.

Answer 2

P0118 GMC Code - Engine Coolant Temperature Circuit High Input
Read more: https://www.autocodes.com/p0118_gmc.html