Circuit Description
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 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 REFERENCE TABLE
| DTC No. | Proceed to | DTC Detection Condition | Trouble Area |
|---|---|---|---|
| P0115 | Step 1 | Open or short in ECT sensor circuit for 0.5 seconds |
|
| P0117 | Step 4 | Short in ECT sensor circuit for 0.5 seconds |
|
| P0118 | Step 2 | Open in ECT sensor circuit for 0.5 seconds |
|
HINT:
After confirming DTC P0115, P0117 or P0118, use the hand-held tester or the OBD II scan tool to confirm the ECT from the ALL menu (to reach the ALL menu: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL).
ENGINE COOLANT TEMPERATURE - REFERENCE TABLE
| Temperature Displayed | Malfunction |
|---|---|
| -40°C (-40°F) | Open circuit |
| 140°C (284°F) or more | Short circuit |