DTC P0118: Engine Coolant Temperature Sensor Circuit - High Input: Notes
WARNING: This page is about a different car, the 2002 Suzuki Esteem. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
If DTCs P0108, P0113, P0118, P0123 and/or P0118 are set along with this DTC, check for an open between ECM and ECT sensor. See WIRING DIAGRAMS
article.