DTC Troubleshooting: P0406 (12)
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.
  1. Turn the ignition switch ON (II).
  1. Check the EGR VLS in the DATA LIST with the HDS.
Is 4.88 V or more indicated?
YES -
Go to Step 3 .
NO -
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the EGR valve and the ECM.■
  1. Turn the ignition switch OFF.
  1. Disconnect the EGR valve 6P connector.
  1. Turn the ignition switch ON (II).
  1. Measure voltage between EGR valve 6P connector terminals No. 2 and No. 3.
Is there about 5 V?
YES -
Go to Step 11 .
NO -
Go to Step 7 .
  1. Turn the ignition switch OFF.
  1. Jump the SCS line with the HDS.
  1. Disconnect ECM connector B (44P).
  1. Check for continuity between ECM connector terminal B33 and EGR valve 6P connector terminal No. 2.
Is there continuity?
YES -
Go to Step 18 .
NO -
Repair open in the wire between the EGR valve and the ECM (B33), then go to Step 13 .
  1. Turn the ignition switch OFF.
  1. Reconnect all connectors and the battery.
  1. Turn the ignition switch ON (II).
  1. Reset the ECM with the HDS.
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0406 indicated?
YES -
Check for poor connections or loose terminals at the EGR valve and the ECM, then go to Step 1 .
NO -
Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.■
  1. Reconnect all connectors.
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0406 indicated?
YES -
Check for poor connections or loose terminals at the EGR valve and the ECM. If the ECM was updated, substitute a known-good ECM, then recheck. If the ECM was substituted, go to Step 1 .
NO -
If the ECM was updated, troubleshooting is complete. If the ECM was substituted, replace the original ECM. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.■