DTC P0115 Engine Coolant Temperature Circuit; DTC P0117 Engine Coolant Temperature Circuit Low Input; DTC P0118 Engine Coolant Temperature Circuit High Input: Description
WARNING: This page is about a different car, the 2007 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.
A thermistor is built into 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 as 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°C (176°F).
DTC DETECTION CONDITION CHART
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0115 | Open or short in ECT sensor circuit for 0.5 seconds (1 trip detection logic) |
|
| P0117 | Short in ECT sensor circuit for 0.5 seconds (1 trip detection logic) |
|
| P0118 | Open in ECT sensor circuit for 0.5 seconds (1 trip detection logic) |
|
HINT:
Confirm the ECT using the intelligent tester. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / COOLANT TEMP.
TEMPERATURE DISPLAYED MALFUNCTION REFERENCE CHART
| Temperature Displayed | Malfunction |
|---|---|
| -40°C (-40°F) | Open circuit |
| 140°C (284°F) or more | Short circuit |