DTC Troubleshooting: P0406
DTC P0406: EGR Valve Position Sensor Circuit High Voltage
NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P0406 EGR Valve Position Sensor Circuit High Voltage
      

1.
Problem verification:

Problem verification
?1.
Turn the vehicle to the ON mode.

?2.
Check the parameter(s) below with the HDS.
Signal
Threshold
Current conditions
Values
Unit
Values
Unit
EGR valve position sensor (EGR VLS)
More than 4.88
V
    

Do the current condition(s) match the threshold?

     
YES
     
     
     
The failure is duplicated. Go to step 2.
     
NO
     
     
     
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the EGR valve and the PCM. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot.?
2.
Determine possible failure area (EGR valve position sensor, others):

Determine possible failure area (EGR valve position sensor, others)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
EGR valve 5P connector

?3.
Turn the vehicle to the ON mode.

?4.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
EGR valve 5P connector: disconnected
Test point 1
EGR valve 5P connector No. 2
Test point 2
EGR valve 5P connector No. 3


Is there about 5.0 V?

     
YES
     
     
     
     
NO
     
     
     
Go to step 3.
3.
Open wire check (SG2 line):

Open wire check (SG2 line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Jump the SCS line with the HDS.


?3.
Disconnect the following connector.
PCM connector C (51P)

?4.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
EGR valve 5P connector: disconnected
PCM connector C (51P): disconnected
Test point 1
EGR valve 5P connector No. 3
Test point 2
PCM connector C (51P) No. 31


Is there continuity?

     
YES
     
     
     
The SG2 wire is OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck. If DTC P0406 goes away and the PCM was updated, troubleshooting is complete. If DTC P0406 goes away and the PCM was substituted, replace the original PCM.?
     
NO
     
     
     
Repair an open in the SG2 wire between the PCM (C31) and the EGR valve.?