1. Measure voltage between ECM/PCM connector terminals A20 and A23.

Is there about 5 V?

YES | - | Repair open in the wire between the EGR valve and the ECM/PCM (A23), then go to Step 10 .
NO | - | Go to Step 14 .

1. Turn the ignition switch OFF.

1. Replace the EGR valve.

1. Turn the ignition switch ON (II).

1. Reset the ECM/PCM with the HDS.

1. Do the ECM/PCM idle learn procedure.

1. Check for Temporary DTCs or DTCs in the DTCs MENU with the HDS.

Are any Temporary DTCs or DTCs indicated?

YES | - | If DTC P0406 is indicated, check for poor connections or loose terminals at the EGR valve and the ECM/PCM, then go to Step 1 . If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.
NO | - | Troubleshooting is complete.■

1. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM.

1. Check for Temporary DTCs or DTCs in the DTCs MENU with the HDS.

Are any Temporary DTCs or DTCs indicated?

YES | - | If DTC P0406 is indicated, check for poor connections or loose terminals at the EGR valve and the ECM/PCM, then go to Step 1 . If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.
NO | - | If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM. ■