1. DTC P0118 description
The engine coolant temperature sensor is installed near the thermostat housing. The engine coolant temperature sensor is a variable resistor and measures the temperature of the engine coolant. This sensor has a signal circuit and a low reference circuit. The ECM supplies 5 V to the signal circuit, and connects the ground to the low reference circuit. The sensor resistance is high when the engine coolant temperature is low, and the sensor resistance decreases as the engine coolant temperature increases. The ECM detects a high voltage when the sensor resistance is high, and a low voltage when the sensor resistance is low. If the ECM detects an excessively high signal voltage, the DTC is set.
2. Condition for setting DTC P0118
Condition for running the DTC
- The battery voltage is 9 to 16 V.
- The ignition switch is ON.
- The engine runtime is 3 minutes or more.
- DTC P060B is not set.
Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) DTC P060B (Flash Code 36) Internal Control Module A/D Processing Performance".
Condition for setting the DTC
- The ECM detects that the engine coolant temperature sensor signal voltage is 4.85 V or more for 3.2 seconds.
3. Action taken when DTC P0118 sets
- Euro4: The ECM illuminates the MIL. Refer to Action taken when DTC sets - Type A (Euro4).
- Except Euro4: The ECM illuminates the check engine warning light. Refer to Action taken when DTC sets - Type A (Except Euro4).
Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) DTC type definitions".
- The ECM assumes a default engine coolant temperature value.
- The ECM limits the fuel injection quantity.
- The ECM inhibits pre-injection.
- The ECM inhibits the EGR control.
- The ECM limits the fuel rail pressure.
- The ECM inhibits the cruise control.
4. Condition for clearing DTC P0118
- Euro4: Refer to Condition for clearing the MIL/DTC - Type A or Type B (Euro4).
- Except Euro4: Refer to Condition for clearing the check engine warning light/DTC - Type A or Type B (Except Euro4).
Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) DTC type definitions".