Circuit Description

The ECT sensor is a thermistor sensor that monitors engine coolant temperature. DTC is set when ECT sensor temperature is 68°F (20°C) or less for at least 20 minutes of engine operation. Possible causes are:

ECT sensor.
Cooling system.

NOTE: If DTCs P0115 and P0116 are both output together, an open may exist in ECT sensor circuit. Perform DTC P0115 test before performing DTC P0116 test. If DTCs P0105, P0106, P0110, P0115 and P0120 are output together, sensor ground circuit may be open. Repair as necessary. See appropriate wiring diagram in WIRING DIAGRAMS article.