P0117
DTC P0117 Engine Coolant Temperature Circuit Low InputCIRCUIT DESCRIPTION
DTC Detection Condition:
A thermistor is built into the engine coolant temperature sensor, and its resistance value varies according to the engine coolant temperature.
The structure of the sensor and its connection to the ECM are the same as those of the intake air temperature sensor.
HINT: If the ECM detects DTC P0115, P0117 or P0118, the ECM enters fail-safe mode in which the engine coolant temperature is assumed to be 80 °C (176 °F).
HINT: When DTC P0115, P0117 or P0118 is detected, check the engine coolant temperature by selecting DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / COOLANT TEMP on the hand-held tester or the OBD II scan tool.
MONITOR DESCRIPTION
Monitor Strategy:
Typical Enabling Conditions:
Typical Malfunction Thresholds:
Component Operating Range:
The engine coolant temperature (ECT) sensor is used to monitor the engine coolant temperature. The ECT sensor has a thermistor with a resistance that varies according to 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. These 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 determines that there is a malfunction in the ECT sensor and sets the DTC.
Example:
If the ECM calculates that the ECT is -40 °C (-40 °F) (P0118) or more than 140 °C (284 °F) (P0117) and if either condition continues for 0.5 seconds or more, the ECM sets the DTC.
If causes of a malfunction are not eliminated by repairs, a DTC is set 0.5 seconds after the engine is started.
Wiring Diagram:
INSPECTION PROCEDURE
Step 1:
Step 1(Continued) - 2:
Step 3:
Step 4 - 5:
HINT:
- If different 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 or the OBD II scan tool. Freeze frame data record the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, 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.
CHECK FOR INTERMITTENT PROBLEMS
HINT:
Hand-held tester only:
Inspect the vehicle's ECM using check mode. Intermittent problems are easier to detect with the hand-held tester when the ECM is in check mode. In check mode, the ECM uses 1trip detection logic, which is more sensitive to malfunctions than normal mode (default) that uses 2trip detection logic.
a. Clear DTCs.
b. Switch the ECM from normal mode to check mode using a hand-held tester.
c. Perform a simulation test.
d. Check and wiggle the harness(es), the connector(s) and terminal(s).