P0118

DTC P0118: Engine Coolant Temp. (ECT) Circuit High Input

Wiring Diagram










DTC Detecting Condition and Trouble Area






DTC Confirmation Procedure

NOTE:

Check to make sure that the following conditions are satisfied when using this DTC confirmation procedure.

- Intake air temp.: -14 °C, 6.8 °F or higher
- Altitude (barometric pressure): 2020 m, 6650 ft or less (540 mmHg, 72 kPa or more)

1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and run it for 30 sec. or more.
4) Check DTC and pending DTC.

DTC Troubleshooting

NOTE:

When this DTC and P1705 are stored together, also clear DTC stored in TCM after completion of repair.

1.
Was "Engine System Check" performed?
YES
Go to Step 2.
NO
Go to Engine System Check Engine System Check.

2. ECT sensor and its circuit check.

Connect scan tool with ignition switch turned OFF.
Turn ignition switch ON.
Check engine coolant temp. displayed on scan tool.

Is -40 °C (-40 °F) indicated?
YES
Go to Step 3.
NO
Intermittent trouble.
Check for intermittent referring to Intermittent and Poor Connection Inspection.

3. Check ECT voltage.

Disconnect connector from ECT sensor with ignition switch turned OFF.
Check proper connection to ECT sensor at "LT GRN" and "ORN" wire terminals.
If OK, then turn ON ignition switch, check voltage between "LT GRN" wire terminal in ECT sensor harness connector and vehicle body ground.






Is voltage about 4 - 6 V at each terminal?
YES
Go to Step 6.
NO
Go to Step 4.

4. Check ECM voltage.

Disconnect connectors from ECM with ignition switch turned OFF.
Remove ECM from vehicle body and connect connectors to ECM.
Check proper connection of connector at "C46-16" terminals.
If OK, then turn ON ignition switch, check voltage between "C46-12" terminal wire and vehicle body ground.

Is voltage about 4 - 6 V at each terminal?
YES
"LT GRN" wire open circuit.
If wire and connection are OK, go to Step 5.
NO
Go to Step 5.

5. Check ECT sensor harness voltage.

Disconnect connector from ECM with ignition switch turned OFF.
Turn ON ignition switch.
Check voltage between "LT GRN" wire terminal in ECT sensor harness connector and vehicle body ground.

Is voltage about 0 V at each terminal?
YES
Go to Step 6.
NO
"LT GRN" wire shorted to other circuits.
If wire are OK, substitute a known-good ECM and recheck.

6. Check ECT sensor harness resistance.

Measure resistance between "C46-12" terminal and "LT GRN" wire terminal in ECT sensor connector with ignition switch turn OFF.

Is resistance below 5 ohms?
YES
Go to Step 7.
NO
"LT GRN" wire in high resistance circuit.

7. Check ECT sensor ground circuit.

Connect connector to ECM.
Check proper connection of ECT sensor at "ORN" wire terminal.
Measure resistance between "ORN" wire terminal in ECT sensor connector and vehicle body ground.

Is resistance below 10 ohms?
YES
Go to Step 9.
NO
Go to Step 8.

8. Check ECT sensor ground circuit.

Measure resistance between "C46-27" terminal and vehicle body ground.

Is resistance below 5 ohms?
YES
"ORN" wire open circuit or high resistance circuit.
Poor "C46-27" connection.
NO
Faulty ECM ground circuit.
If circuit are OK, substitute a known-good ECM and recheck.

9. Check ECT sensor.

Check ECT sensor according to Engine Coolant Temperature (ECT) Sensor Inspection Engine Coolant Temperature (ECT) Sensor Inspection.

Is it good condition?
YES
Substitute a known-good ECM and recheck.
NO
Replace ECT sensor.