Code No. P0118: Engine Coolant Temperature Sensor Circuit High Input




OPERATION




FUNCTION




TROUBLE JUDGEMENT


Check Conditions
Judgement Criterion

FAIL-SAFE AND BACKUP FUNCTION




PROBABLE CAUSES




DIAGNOSIS PROCEDURE


STEP 1. M.U.T.-III data list



  • Item 6: Engine coolant temperature sensor
OK:
    Engine cold state: At ambient temperature (atmospheric temperature) or equivalent.
    Engine hot state: At 80 - 120°C

Q. Is the check result normal?

Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
Go to Step 2.

STEP 2. Check engine coolant temperature sensor itself.



  • Engine coolant temperature sensor connector check.
  • Engine coolant temperature sensor check (Refer to ).

Q. Is the check result normal?

Go to Step 3.
Repair or replace the connector, or replace the engine coolant temperature sensor.

STEP 3. Perform voltage measurement at engine coolant temperature sensor connector.



  • Disconnect connector, and measure at harness side.
  • Power supply mode of electric motor switch: ACC
  • Voltage between terminal engine-ECU WTS line and body earth.
OK: 4.5 - 4.9 V

Q. Is the check result normal?

Go to Step 6.
Go to Step 4.

STEP 4. Check harness between engine coolant temperature sensor connector terminal and engine-ECU connector terminal WTS.



  • Check output line for open circuit.

Q. Is the check result normal?

Go to Step 5.
Repair or replace the connector, or repair the damaged harness wire.

STEP 5. M.U.T.-III data list



  • Item 6: Engine coolant temperature sensor
OK:
    Engine cold state: At ambient temperature (atmospheric temperature) or equivalent.
    Engine hot state: At 80 - 120 °C

Q. Is the check result normal?

Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
Replace the engine-ECU.

STEP 6. Perform resistance measurement at engine coolant temperature sensor connector.



  • Disconnect connector, and measure at harness side.
  • Resistance between terminal engine-ECU WTSE line and body earth.
OK: Continuity (2 Ω or less)

Q. Is the check result normal?

Go to Step 8.
Go to Step 7.

STEP 7. Check harness between engine coolant temperature sensor connector terminal and engine-ECU connector terminal WTSE.



  • Check earthing line for open circuit and damage.

Q. Is the check result normal?

Go to Step 5.
Repair or replace the connector, or repair the damaged harness wire.

STEP 8. Check harness between engine coolant temperature sensor connector terminal and engine-ECU connector terminal WTS.



  • Check output line for damage.

Q. Is the check result normal?

Go to Step 5.
Repair or replace the connector, or repair the damaged harness wire.