1. DTC P0406 description
The EGR position sensor is installed inside the EGR valve together with the EGR motor. The EGR position sensor changes the signal voltage in accordance with the EGR valve opening position. The sensor has the following circuits.
- 5 V reference circuit
- Low reference circuit
- EGR position sensor signal circuit
The EGR position sensor sends signals related to EGR valve position changes to the ECM via the signal circuit. If the ECM detects an excessively high signal voltage, the DTC is set.
2. Condition for setting DTC P0406
Condition for running the DTC
- The battery voltage is 9 to 16 V.
- 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 EGR position sensor signal voltage is 4.9 V or more for 3.2 seconds.
3. Action taken when DTC P0406 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 inhibits pre-injection.
- The ECM limits the fuel rail pressure.
- The ECM inhibits the cruise control.
4. Condition for clearing DTC P0406
- 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".