P0116 - Engine Coolant Temperature Sensor Circuit Performance: Notes
Theory of Operation
Engine Coolant Temperature Sensor performance looks at the outputs of three temperature sensors and compares them under cold start conditions. Following a start to run delay time, the outputs of the Ambient, Engine Coolant and Intake Air Temperature Sensors will be compared. If the Intake Air and Ambient Air Temperature Sensors agree and the Engine Coolant Temperature does not agree, the Engine Coolant Temperature Sensor is declared as irrational.
- >>When Monitored:<< Engine off time is greater than 480 minutes and the vehicle has been driven for one minute over 35 mph. Ambient temperature is greater than -64°C (-83°F).
- >>Set Condition:<< Once the vehicle is soaked for a calibrated engine off time and then driven over calibrated speed and load conditions for some calibrated time, the PCM compares the Ambient, Engine Coolant and Intake Air Temperature Sensor values. If Ambient Air and Intake Air Temperature Sensors agree with each other but Engine Coolant Temperature does not agree with them, the Engine Coolant Temperature Sensor is declared as irrational. Two Trip Fault. Three good trips to turn off the MIL.
| Possible Causes |
|---|
| EXCESSIVE RESISTANCE IN THE (K2) ECT SIGNAL CIRCUIT |
| EXCESSIVE RESISTANCE IN THE (K900) SENSOR GROUND CIRCUIT |
| ENGINE COOLANT TEMPERATURE (ECT) SENSOR |
| POWERTRAIN CONTROL MODULE (PCM) |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to Pre-Diagnostic Troubleshooting Procedure .