Troubleshooting

DTC P0118 ENGINE COOLANT TEMPERATURE CIRCUIT HIGH INPUT

CIRCUIT DESCRIPTION

DTC Detecting Condition:

A thermistor built into the engine coolant temperature sensor 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 those of the intake air temperature sensor.

If the ECM detects the DTC P0115, P0117 or P0118, it operates the fail-safe functions in which the engine coolant temperature is assumed to be 80 °C (176 °F).






HINT: After confirming DTC P0115, P0117 or P0118, use the hand-held tester or the OBD II scan tool to check the engine coolant temperature from the DIAGNOSIS/ENHANCED OBD II/DATA LIST/ALL DATA.

Wiring Diagram:

Step 1:

Step 2:

Step 3:

Step 4:

Step 5:

INSPECTION PROCEDURE

HINT:
- If different DTCs that are related to different Systems are output simultaneously while terminal E2 is used as a ground terminal, terminal E2 may be open.
- Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time of the malfunction.

CHECK FOR INTERMITTENT PROBLEMS

hand-held tester only:
By putting the vehicle's ECM in the check mode, 1 trip detection logic is possible instead of 2 trip detection logic and sensitivity to detect open circuits is increased. This makes it easier to detect intermittent problems.

1. Clear the DTC.
2. Set the check mode.
3. Perform a simulation test.
4. Check the connector and terminal.
5. Handle the connector.