DTC P0405 (Flash Code 44) EGR Sensor Circuit Low (RZ4E-TC)

1. Engine control system check

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

2. Prioritized DTC check

1) Connect the scan tool.

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

3) Start the engine.

4) Observe the DTC information with a scan tool. Is DTC P1655 set at the same time?

Yes

Go to DTC P1655 diagnosis.

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

=>Go to EGR position sensor signal voltage check.

3. EGR position sensor signal voltage check

1) Observe the Exhaust Gas Recirculation (EGR) Valve Position parameter on the scan tool. Is the Exhaust Gas Recirculation (EGR) Valve Position parameter less than or equal to the specified value?

Value: 0.1 V

Yes

=>Go to EGR position sensor 5 V reference voltage check.

Go to Intermittent conditions of engine.

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

4. EGR position sensor 5 V reference voltage check

1) Turn OFF the ignition switch.

2) Disconnect the EGR valve harness connector (E49).

3) Turn ON the ignition switch.

4) Measure the voltage between the EGR position sensor 5 V reference circuit (pin 1 of E49) and the body ground with a DMM. Is the voltage more than or equal to the specified value?

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.).

Value: 4.5 V

Yes

=>Go to EGR position sensor signal voltage check using fused jumper wire.

=>Go to Inspection for open circuit in EGR position sensor 5 V reference circuit.

5. EGR position sensor signal voltage check using fused jumper wire

1) Connect a fused jumper wire between the EGR position sensor 5 V reference circuit and the signal circuit (pins 1 and 3 of E49).

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.).

2) Observe the Exhaust Gas Recirculation (EGR) Valve Position parameter on the scan tool. Is the Exhaust Gas Recirculation (EGR) Valve Position parameter more than or equal to the specified value?

Value: 4.5 V

Yes

=>Go to EGR valve harness connector inspection.

=>Go to Inspection for open circuit and short circuit in EGR position sensor signal circuit.

6. Inspection for open circuit in EGR position sensor 5 V reference circuit

1) Inspect the position sensor 5 V reference circuit between the ECM (pin 14 of E4) and the EGR valve (pin 1 of E49) for an open circuit or high resistance. Is the result normal?

Caution

The EGR position sensor shares the 5 V reference circuit with other sensors. A malfunction in the 5 V 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. Inspection for open circuit and short circuit in EGR position sensor signal circuit

1) Inspect the position sensor signal circuit between the ECM (pin 11 of E4) and the EGR valve (pin 3 of E49) for the following. Is the result normal?

Open circuit
Short to ground
Short to the low reference circuit
High resistance

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.

8. EGR valve harness connector inspection

1) Inspect for poor connections at the EGR valve harness connector (pins 1 and 3 of E49). 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 EGR valve.

Refer to "1.Engine 1H.Aux. Emission Control Devices(RZ4E-TC) EGR removal".

Refer to "1.Engine 1H.Aux. Emission Control Devices(RZ4E-TC) EGR installation".

=>Go to Repair verification.

Repair the connections as necessary.

=>Go to Repair verification.

9. ECM harness connector inspection

1) Inspect for poor connections at the ECM harness connector (pins 11 and 14 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.

10. 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.

11. 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.