1. DTC P0238 description
The boost pressure sensor is installed to the air duct, and is integrated with the CAC temperature sensor. The boost pressure sensor changes the signal voltage in accordance with changes in air pressure in the air intake pipe. The sensor has the following circuits.
- 5 V reference circuit
- Low reference circuit
- Boost pressure sensor signal circuit
The boost pressure sensor transmits signals related to air pressure changes within the air intake pipe to the ECM via the signal circuit. The ECM detects a low signal voltage in low boost pressure, such as when the engine is under low load. The ECM detects a high signal voltage in high boost pressure, such as when the engine is under high load. If the ECM detects an excessively high signal voltage, the DTC is set.
2. Condition for setting DTC P0238
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 boost pressure sensor signal voltage is 4.9 V or more for 2.6 seconds.
3. Action taken when DTC P0238 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 boost pressure 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 P0238
- 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".