DTC P0406

DTC P0406: EGR Valve Position Sensor Circuit High Voltage

General Description

Courtesy of HONDA, U.S.A., INC.

The powertrain control module (PCM) controls the exhaust gas recirculation (EGR) valve opening. The system includes the EGR actuator, the EGR valve, the EGR valve position sensor, and the PCM. The EGR valve position sensor is a semiconductor type, and it is attached to the EGR valve and shaft to determine EGR valve position. The EGR valve position signal from the EGR valve position sensor is transmitted to the PCM for target position feedback control. If the EGR valve position sensor output voltage is a specified value, the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type

Execution	Continuous
Sequence	None
Duration	2 seconds or more
DTC Type	Two drive cycles, MIL on

Enable Conditions

Condition
State of the engine	Running

Malfunction Threshold

The EGR valve position sensor output voltage [EGR valve position sensor (EGR Vls)] is 4.89 V or more for at least 2 seconds.

[ ]: HDS Parameter

Possible Cause

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.

EGR valve position sensor failure
EGR valve position sensor EGRL line short to EGR valve position sensor VCC line
PCM internal circuit failure

Diagnosis Details

Conditions for setting the DTC

When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC and the freeze data are stored.

Conditions for clearing the DTC

The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the 12 volt battery.