P0118

Description
ECT SENSOR CIRCUIT HIGH VOLTAGE

Engine Coolant Temperature (ECT) sensor is a thermistor that
varies resistance based on temperature. As temperature of sensor
increases, resistance decreases. Low temperature will result in a high
signal voltage. DTC will set when PCM sees an excessively high ECT
sensor voltage signal.

Potential Symptoms

• Very poor fuel economy
• Engine wont start
• Engine may start, but run very poorly, blowing black smoke, running very rough and misfiring
• SES light

Causes

• Corroded connection at the sensor
• Brake in the ground wire between sensor and PCM
• A short in the wire between the sensor and the PCM
• Defective ECT sensor

Possible Solutions

• Check connection at the sensor, clean if needed
• Test ground wire
• Test signal wire for short.
• Replace ECT sensor