P0117

DTC P0115 ENGINE COOLANT TEMPERATURE CIRCUIT
DTC P0117 ENGINE COOLANT TEMPERATURE CIRCUIT LOW INPUT
DTC P0118 ENGINE COOLANT TEMPERATURE CIRCUIT HIGH INPUT

CIRCUIT DESCRIPTION

DTC Detection Condition:

A thermistor is built in the Engine Coolant Temperature (ECT) sensor and changes the resistance value according to the engine coolant temperature.

The structure of the sensor and connection to the ECM is the same the Intake Air Temperature (IAT) sensor.

HINT: If the ECM detects the DTC "P0115, P0117 or P0118", it operates the fail-safe function in which the ECT is assumed to be 80 degrees C (176 degrees F).

HINT: After confirming DTC P0115, P0117 or P0118, confirm the engine coolant temperature using the menu "DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL" on the hand-held tester.

MONITOR DESCRIPTION

Monitor Strategy:

Typical Enabling Conditions:

Typical Malfunction Thresholds:

Component Operating Range:

The ECT sensor is used to monitor the engine coolant temperature. The ECT sensor has a thermistor that varies its resistance depending on the temperature of the engine coolant. When the coolant temperature is low, the resistance in the thermistor increases. When the temperature is high, the resistance drops. The variations in resistance are reflected in the voltage output from the sensor. The ECM monitors the sensor voltage and uses this value to calculate the engine coolant temperature. When the sensor output voltage deviates from the normal operating range, the ECM interprets this as a fault in the ECT sensor and sets a DTC.

Example: When the ECM calculates that the ECT is -40 degrees C (-40 degrees F) or more than 140 degrees C (284 degrees F) and if either condition continues for 0.5 seconds or more, the ECM will set a DTC. This monitor runs 0.5 seconds after the ignition switch is turned ON.

Wiring Diagram:

Step 1:

Step 2-3:

Step 4-5:

INSPECTION PROCEDURE

HINT:
- If DTCs related to different systems that have terminal E2 as the ground terminal are output simultaneously, terminal E2 may have an open circuit.
- Read freeze frame data using the hand-held tester. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air-fuel ratio was LEAN or RICH, and other data from the time the malfunction occurred.