P0118: Engine Coolant Temperature (ECT) Sensor 1 Circuit High Input

WARNING: This page does not describe the selected car, but rather 30 other vehicles, including the 2004 Mercury Sable, 2004 Mercury Mountaineer, 2004 Mercury Monterey, 2004 Mercury Marauder, and 2004 Mercury Grand Marquis. However, it is still accessible from the selected car via links, so may be relevant.

P0118 - ENGINE COOLANT TEMPERATURE (ECT) SENSOR 1 CIRCUIT HIGH INPUT

Description:	Indicates the sensor signal is greater than the self-test maximum. The ECT sensor maximum is 4.6 volts or -50°C (-58°F). NOTE: on some vehicles that are not equipped with an ECT sensor, a cylinder head temperature (CHT) sensor can be used and can set this DTC.
Possible Causes:	Open circuit in the harness. Sensor signal short to power. Damaged PCM. Improper harness connection. Damaged sensor.
Diagnostic Aids:	An ECT V PID reading greater than 4.6 volts with key ON and engine OFF or during any engine operating mode indicates a hard fault.
Application	Key On Engine Off	Key On Engine Running	Continuous Memory
Vehicles with a CHT sensor only	GO to PINPOINT TEST DL: CYLINDER HEAD TEMPERATURE (CHT) SENSOR Step 7.	GO to PINPOINT TEST DL: CYLINDER HEAD TEMPERATURE (CHT) SENSOR Step 7.	GO to PINPOINT TEST DL: CYLINDER HEAD TEMPERATURE (CHT) SENSOR Step 15.
Vehicles with an ECT sensor only	GO to PINPOINT TEST DX: ENGINE COOLANT TEMPERATURE (ECT) SENSOR Step 7.	GO to PINPOINT TEST DX: ENGINE COOLANT TEMPERATURE (ECT) SENSOR Step 7.	GO to PINPOINT TEST DX: ENGINE COOLANT TEMPERATURE (ECT) SENSOR Step 15.
Vehicles with both CHT and ECT sensor	GO to PINPOINT TEST DX: ENGINE COOLANT TEMPERATURE (ECT) SENSOR Step 7.	GO to PINPOINT TEST DX: ENGINE COOLANT TEMPERATURE (ECT) SENSOR Step 7.	GO to PINPOINT TEST DX: ENGINE COOLANT TEMPERATURE (ECT) SENSOR Step 15.