P0115 - ECT Circuit Malfunction

The Engine Coolant Temperature (ECT) sensor circuit is monitored by the Powertrain Control Module (PCM). The test fails if an excessively high or low voltage from the ECT sensor is sent to the PCM. When this fault occurs the PCM will enter into the fail safe mode.

Possible Causes:
^ ECT sensor circuit is open.
^ ECT sensor circuit is shorted to VPWR
^ ECT sensor circuit is shorted to GND
^ Damaged ECT sensor

Diagnostic Aids:
With a ECT PID reading an engine coolant temperature of 20°C (68°F) the resistance across the ECT sensor should not be between 2.1 - 2.9 kohms.