The P0118 code means that the engine control module (ECM) has detected a voltage signal that’s too high from the engine coolant temperature (ECT) sensor (below). In practical terms, the ECM believes ...
If you just bought an old, beaten-up Corolla, you might end up stranded on the side of the road with a lot of steam coming from the engine bay and some spills on the ground. Just don't panic, and here ...