• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
---|---|---|---|---|---|
ECT Sensor Signal | P0117 | P0118 | P0118 | P0118 | P0116, P0128 |
Low Reference | -- | P0118 | P0118 | P0118 | P0128 |
Circuit | Normal Range | Short to Ground | Open | Short to Voltage |
---|---|---|---|---|
ECT Sensor Signal | -39°C to +120°C (-38°F to +248°F) | 150°C (303°F) | -40°C (-40°F) | -40°C (-40°F) |
Low Reference | -- | -- | -40°C (-40°F) | -40°C (-40°F) |
The engine coolant temperature (ECT) sensor is a variable resistor that measures the temperature of the engine coolant. The control module supplies 5 volts to the signal circuit and a ground for the ECT low reference circuit. When the ECT is low, the sensor resistance is high. When the ECT is high, the sensor resistance is low. The control module uses this High Side Coolant Rationality test to determine if the ECT input is skewed high. The internal clock of the control module will record the amount of time the ignition is OFF. At restart, the control module will compare the temperature difference between the ECT and the intake air temperature (IAT). Before failing this test, the control module will perform a calculation to determine the presence of an engine block heater. If the control module detects that the temperature difference between the ECT and the IAT is not within the calibrated range after the ignition OFF time, DTC P0116 sets.
• | DTCs P0112, P0113, P0117, P0118, P0502, P0503, P0601, P0602, P0604, P0606, P2610 are not set. |
• | The ignition is ON. |
• | The IAT parameter is more than 15°C (59°F). |
• | The Fuel Level Sensor parameter is more than 10 percent. |
• | The vehicle has a minimum ignition OFF time of 8 hours. |
• | This diagnostic runs once per ignition cycle when the above conditions are met. |
• | The control module detects a temperature difference between the ECT sensor and the IAT sensor of more than 100°C (180°F) at start up. |
OR |
• | The control module detects a temperature difference between the ECT sensor and the IAT sensor of more than 15°C (27°F) and the time elapsed cranking the engine without starting is more than 5 seconds. |
OR |
• | The control module detects a temperature difference between the ECT sensor and the IAT sensor of more than 15°C (27°F). The vehicle must then be driven for 5 minutes over 40 km/h (25 mph). If the IAT sensor temperature decreases more than 5°C (9°F), an engine block heater was detected and the test is aborted. If the IAT sensor temperature does not decrease, an engine block heater was not detected and DTC P0116 will set. |
DTC P0116 is a type B DTCs.
DTC P0116 is a type B DTCs.
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Caution: Under pressure, the temperature of the solution in the radiator can be considerably higher, without boiling. Removing the radiator cap while the engine is hot (pressure is high), will cause the solution to boil instantaneously, with explosive force. The solution will spew out over the engine, fenders, and the person removing the cap. Serious bodily injury may result. Flammable antifreeze, such as alcohol, is not recommended for use at any time. Flammable antifreeze could cause a serious fire.
Important: A critical analysis of the operation of the thermostat is necessary to properly diagnose these DTCs.
Important: All electrical components and accessories must be turned OFF and allowed to power down.
⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM. |
⇒ | If greater than the specified range, test the signal circuit terminal B for a short to ground. If the circuit tests normal, replace the ECM. |
⇒ | If less than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM. |
Measure and record the resistance of the ECT sensor at various ambient temperatures, then compare those measurements to the Temperature vs Resistance table. Refer to Temperature Versus Resistance .
• | Control Module References for PCM replacement, setup, and programming |