Ford P0116 OBD-II Trouble Code Definition:
P0116 Engine Coolant Temperature Sensor 1 Circuit Range/Performance Problem
P0116 Ford OBD-II Trouble CodeDescription:
The ECT (Engine coolant temperature) sensor is a thermistor which changes resistance based on temperature of the coolant in contact with it. The ECT sensor will be located in the block or coolant passage. Usually it is a two wire sensor. One wire is a 5 Volt supply from the PCM (Powertrain Control Module) to the ECT. The other is a ground to the ECT.
As the temperature of the coolant changes the resistance on the signal wire changes accordingly. The PCM monitors the reading and determines coolant temperature in order to perform essential engine fuel management. When engine coolant is low, sensor resistance is high. The PCM will see a high signal voltage (low temperature). When coolant is warm, the sensor’s resistance is low and the PCM will see a high temperature. The PCM expects to see slow resistance changes on the ECT signal circuit. If it sees a quick change in voltage that isn’t consistent with an engine warming up, this P0116 code will set. Or if it sees a lack of change in ECT signal, this code may set.
There may be no noticeable symptoms if the problem is very intermittent, however the following may occur: MIL (Malfunction Indicator Lamp) illumination Poor drivability Black smoke at tailpipe Poor fuel economy May not idle May exhibit stalling or misfires
Potential causes of the P0116 code include: Missing or stuck-open thermostat Bad ECT sensor Short or open on signal wire Short or open on ground wire Poor connections in wiring