DTC P0118 [WL-C, WE-C (Australian, European (L.H.D. U.K.) specs.)]


id0102c4804100

DTC P0118

Engine coolant temperature (ECT) sensor circuit high input

DETECTION CONDITION
•  The PCM monitors the input signal from the ECT sensor. If the voltage from the ECT sensor is more than 4.91 V for 1.0 s, the PCM determines that there is a malfunction in the ECT sensor circuit.
POSSIBLE CAUSE
•  ECT sensor malfunction
•  Connector or terminal malfunction
•  Open circuit in wiring harness between ECT sensor terminal B and PCM terminal 167
•  Short to power supply in wiring harness between ECT sensor terminal B and PCM terminal 167
•  Open circuit in wiring harness between ECT sensor terminal A and PCM terminal 156
•  PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

1
VERIFY FREEZE FRAME DATA HAS BEEN RECORDED
•  Has FREEZE FRAME DATA been recorded?
Yes
Go to the next step.
No
Record the FREEZE FRAME DATA on the repair order, then go to the next step.
2
VERIFY RELATED SERVICE INFORMATION AVAILABILITY
•  Verify related service information availability.
•  Is any related service information available?
Yes
Perform repair or diagnosis according to the available service information.
•  If the vehicle is not repaired, go to the next step.
No
Go to the next step.
3
VERIFY CURRENT SIGNAL STATUS: IS CONCERN INTERMITTENT OR CONSTANT?
•  Connect the M-MDS to the DLC-2.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Start the engine.
•  Is the same DTC present?
Yes
Go to the next step.
No
Intermittent concern exists.
Perform the “INTERMITTENT CONCERN TROUBLESHOOTING”.
4
INSPECT ECT SENSOR/ WATER TEMPERATURE SENDER UNIT CONNECTOR FOR POOR CONNECTION
•  Turn the engine switch off.
•  Disconnect the ECT sensor/ water temperature sender unit connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the terminal, then go to Step 9.
No
Go to the next step.
5
INSPECT ECT SENSOR SIGNAL CIRCUIT FOR SHORT TO POWER SUPPLY
•  Turn the engine switch to the ON position (Engine off).
•  Measure the voltage between ECT sensor terminal B (wiring harness-side) and body ground.
•  Is the voltage more than 4.91 V?
Yes
Repair or replace the wiring harness for a possible short to power supply, then go to Step 9.
No
Go to the next step.
6
INSPECT ECT SENSOR
•  Is there any malfunction?
Yes
Replace the ECT sensor, then go to Step 9.
No
Go to the next step.
7
INSPECT PCM CONNECTOR FOR POOR CONNECTION
•  Turn the engine switch off.
•  Disconnect the PCM connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the terminal, then go to Step 9.
No
Go to the next step.
8
INSPECT ECT SENSOR CIRCUIT FOR OPEN CIRCUIT
•  Turn the engine switch off.
•  Inspect for continuity between the following terminals:
―  ECT sensor terminal B (wiring harness-side) and PCM terminal 167 (wiring harness-side)
―  ECT sensor terminal A (wiring harness-side) and PCM terminal 156 (wiring harness-side)
•  Is there continuity?
Yes
Go to the next step.
No
Repair or replace the wiring harness for a possible open circuit, then go to the next step.
9
VERIFY TROUBLESHOOTING OF DTC P0118 COMPLETED
•  Turn the engine switch off.
•  Make sure to reconnect all disconnected connectors.
•  Turn the engine switch to the ON position (Engine off).
•  Clear the DTC from the PCM memory using the M-MDS.
•  Run the vehicle under the FREEZE FRAME DATA stored condition.
•  Is the same DTC present?
Yes
Replace the PCM, then go to the next step.
No
Go to the next step.
10
VERIFY AFTER REPAIR PROCEDURE
•  Perform the “After Repair Procedure“.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
No
DTC troubleshooting completed.