1. Disconnect the vacuum hose (A) from the turbocharger boost control solenoid (B), and connect a vacuum pump/gauge (C) to the solenoid.

1. Turn the ignition switch ON (II).

1. Apply vacuum to the hose.

Does the turbocharger boost control diaphragm operate?

YES | - | Replace the turbocharger boost control solenoid, then go to Step 18 .
NO | - | Replace the turbocharger assembly, then go to Step 18 .

1. Reconnect all hoses.

1. Turn the ignition switch ON (II).

1. Reset the ECM with the HDS.

1. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters:
   - ENGINE SPEED
   - VSS

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

Are any Temporary DTCs or DTCs indicated?

YES | - | If DTC P1401 is indicated, check for poor connections or loose terminals at the EGR control solenoid valve, the turbocharger boost control solenoid and the ECM, then go to Step 1 . If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.
NO | - | Go to Step 23 .

1. Monitor the OBD STATUS for DTC P1401 in the DTCs MENU with the HDS.

Does the screen indicate PASSED?

YES | - | Troubleshooting is complete.■
NO | - | If the screen indicates FAILED, check for poor connections or loose terminals at the EGR control solenoid valve, the turbocharger boost control solenoid and the ECM, then go to Step 1 . If the screen indicates NOT COMPLETED, go to Step 21 and recheck.