DTC Troubleshooting: P0406
DTC P0406: EGR Valve Position Sensor Circuit High Voltage
NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and 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.
Press the engine start/stop button to select 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.?
2.
Determine possible failure area (EGR valve position sensor, others):

Determine possible failure area (EGR valve position sensor, others)
?1.
Press the engine start/stop button to select the OFF mode.

?2.
Disconnect the following connector.

?3.
Press the engine start/stop button to select the ON mode.

?4.
Measure the voltage between test points 1 and 2.
Test condition
ON mode
EGR 5P connector: disconnected
Test circuit
VCC1, SG1
Test point 1
EGR valve 5P connector No. 2 (PNK)
Test point 2
EGR valve 5P connector No. 3 (BLU)


Is there about 5.0 V?

     
YES
     
     
     
     
NO
     
     
     
Go to step 3.
3.
Open wire check (SG1 line):

Open wire check (SG1 line)
?1.
Press the engine start/stop button to select the OFF mode.

?2.
Jump the SCS line with the HDS.


?3.
Disconnect the following connector.

?4.
Check for continuity between test points 1 and 2.
Test condition
OFF mode
EGR 5P connector: disconnected
PCM connector C (51P): disconnected
Test circuit
SG1
Test point 1
EGR valve 5P connector No. 3 (BLU)
Test point 2
PCM connector C (51P) No. 33 (BLU)


Is there continuity?

     
YES
     
     
     
The SG1 wire is OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM, then do the repair verification.
     
NO
     
     
     
Repair an open in the SG1 wire between the PCM (C33) and the EGR valve, then do the repair verification.
Repair verification:

?1.
Press the engine start/stop button to select the OFF mode.

?2.
Reconnect all connectors.

?3.
Exit the SCS mode with the HDS.


?4.
Press the engine start/stop button to select the ON mode.

?5.
Reset the PCM with the HDS.


?6.
Do the PCM idle learn procedure.

?7.
Check for Pending or Confirmed DTCs with the HDS.
DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P0406 EGR Valve Position Sensor Circuit High Voltage
      


Is DTC P0406 indicated?

     
YES
     
     
     
Check for poor connections or loose terminals at the EGR valve and the PCM. If the PCM was updated, substitute a known-good PCM, then recheck. If the PCM was substituted, go to step 1.
     
NO
     
     
     
Troubleshooting is complete. If the PCM was substituted, replace the original PCM. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.?