|P0116 – Engine Coolant Temperature (ECT) Sensor 1 Circuit Range/Performance|
|Description: Indicates the engine coolant temperature rationality test has failed. This DTC indicates the ECT or cylinder head temperature (CHT) value is higher than the calibrated value and could prevent one or more on board diagnostic (OBD) monitors from completing.
The powertrain control module (PCM) runs this logic after an engine off and a calibrated soak period (typically 6 hours). This soak period allows the intake air temperature (IAT) and the CHT or ECT to stabilize and not differ by more than a calibrated value. DTC P0116 sets when all of the following conditions are met:
The ECT at engine start exceeds the IAT at engine start by more than a calibrated value, typically 17°C (30°F).
The ECT exceeds a calibrated value, typically 107°C (225°F).
The fuel system, heated oxygen and misfire monitors have not completed. The calibrated time to set DTC P0116 has expired.
Possible Causes: • ECT or CHT sensor
• Coolant system concern
Diagnostic Aids: Make sure the IAT and the ECT are similar when the engine is cold. Also make sure the ECT or CHT sensor and the actual engine operating temperatures are the same.