1. DTC P0112 description
The IAT sensor is installed between the air cleaner and the turbocharger and is integrated with the MAF sensor. The IAT sensor is a variable resistor and measures the temperature of the air flowing into the engine. This sensor has a signal circuit and a low reference circuit. The ECM supplies 5 V to the signal circuit and ground to the low reference circuit. When the IAT sensor is cold, the resistance of the sensor is high. As the air temperature rises, the sensor resistance decreases. The ECM detects a high voltage when the sensor resistance is high. The ECM detects a low voltage when the sensor resistance is low. If the ECM detects an excessively low or high signal voltage, the DTC is set.
2. Condition for setting DTC P0112
Condition for running the DTC
- The battery voltage is 9 to 16 V.
- The ignition voltage is 9 to 16 V.
- The ignition switch is ON.
- 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 IAT sensor signal voltage is 0.1 V or less for 3.2 seconds.
3. Action taken when DTC P0112 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 IAT value.
- The ECM limits the fuel injection quantity.
- The ECM inhibits pre-injection.
- The ECM inhibits the EGR control.
- The ECM inhibits the cruise control.
4. Condition for clearing DTC P0112
- 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".