DTC P0238 (Flash Code 32) Turbocharger Boost Sensor Circuit High (RZ4E-TC)

1. Engine control system check

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) Diagnostic system check-engine controls".

2. Boost pressure sensor signal voltage check

1) Connect the scan tool.

2) Turn OFF the ignition switch for 30 seconds or more.

3) Start the engine.

4) Observe the Boost Pressure Sensor parameter on the scan tool. Is the Boost Pressure Sensor parameter more than or equal to the specified value?

Value: 4.9 V

Yes

=>Go to Prioritized DTC and boost pressure sensor signal voltage check.

Go to Intermittent conditions of engine.

Refer to "202.Engine 15D.Symptom(RZ4E-TC) intermittent conditions of engine".

3. Prioritized DTC and boost pressure sensor signal voltage check

1) Observe the DTC information with a scan tool for DTC P1655 being set at the same time.

2) Turn OFF the ignition switch.

3) Disconnect the boost pressure and CAC temperature sensor harness connector (E51).

Refer to "RHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "LHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

4) Turn ON the ignition switch.

5) Observe the Boost Pressure Sensor parameter on the scan tool.

Value: 0.1 V

The reading is more than the specified value.

=>Go to Inspection for short to power supply in boost pressure sensor signal circuit.

The reading is less than or equal to the specified value and DTC P1655 is set.

Go to DTC P1655 diagnosis.

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) DTC P1655 (Flash Code 59) Sensor Reference Voltage 4 Circuit".

The reading is less than or equal to the specified value and DTC P1655 is not set.

=>Go to Boost pressure sensor low reference circuit inspection using test lamp.

4. Boost pressure sensor low reference circuit inspection using test lamp

1) Connect a test lamp between the boost pressure sensor low reference circuit (pin 2 of E51) and the battery power supply. Does the test lamp illuminate?

Refer to "RHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "LHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

=>Go to Boost pressure and CAC temperature sensor harness connector inspection.

=>Go to Inspection for open circuit in boost pressure sensor low reference circuit.

5. Inspection for short to power supply in boost pressure sensor signal circuit

1) Inspect the boost pressure sensor signal circuit between the ECM (pin 10 of E4) and the boost pressure and CAC temperature sensor (pin 1 of E51) for the following. Is the result normal?

Short to the battery power supply circuit or short to the ignition power supply circuit
Short to the 5 V reference circuit

Note

The boost pressure sensor may be damaged if the sensor signal circuit is shorted to the power supply.

Refer to "RHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "LHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

=>Go to ECM replacement.

Repair the circuit as necessary.

=>Go to Repair verification.

6. Inspection for open circuit in boost pressure sensor low reference circuit

1) Inspect the boost pressure sensor low reference circuit between the ECM (pin 28 of E4) and the boost pressure and CAC temperature sensor (pin 2 of E51) for an open circuit or high resistance. Is the result normal?

Note

The boost pressure sensor shares the low reference circuit with other sensors. A malfunction in the low reference circuit may set DTCs on sensors that share this circuit.

Refer to "RHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "LHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

=>Go to ECM harness connector inspection.

Repair the circuit as necessary.

=>Go to Repair verification.

7. Boost pressure and CAC temperature sensor harness connector inspection

1) Inspect for poor connections at the boost pressure and CAC temperature sensor harness connector (pin 2 of E51). Is the connection status normal?

Refer to "RHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "LHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

Replace the boost pressure and CAC temperature sensor.

Refer to "1.Engine 1Z.Engine Electrical Control(RZ4E-TC) boost pressure and CAC temperature sensor removal".

Refer to "1.Engine 1Z.Engine Electrical Control(RZ4E-TC) boost pressure and CAC temperature sensor installation".

=>Go to Repair verification.

Repair the connections as necessary.

=>Go to Repair verification.

8. ECM harness connector inspection

1) Inspect for poor connections at the ECM harness connector (pin 28 of E4). Is the connection status normal?

Refer to "RHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "LHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

=>Go to ECM replacement.

Repair the connections as necessary.

=>Go to Repair verification.

9. ECM replacement

Note

Perform programming after replacing the ECM.

Refer to "1.Engine 1Z.Engine Electrical Control(RZ4E-TC) ECM removal".

Refer to "1.Engine 1Z.Engine Electrical Control(RZ4E-TC) ECM installation".

Refer to "1.Engine 1Z.Engine Electrical Control(RZ4E-TC) ECM setting".

Procedure completion

=>Go to Repair verification.

10. Repair verification

1) Clear the DTC with a scan tool.

2) Turn OFF the ignition switch for 30 seconds or more.

3) Start the engine.

4) Operate the vehicle under the conditions for running the DTC.

5) Observe the DTC information with a scan tool.