Circuit Description

The turbocharger (TC) learns the vane positions automatically during each ignition cycle. The engine control module (ECM) performs the turbocharger learn procedure automatically when the enable criteria are met. After each ignition cycle, and before the enable criteria have been met, the ECM will use the previously learned value. If the ECM does not have a previously learn value, it will default to a stored calibrated value. The ECM will use this value until the enable criteria have been met. It will then perform this procedure to learn the new value. If the ECM attempts to perform the learn procedure and fails, DTCs P003A or P2563 may set.

The turbocharger learn procedure must be performed manually or with a Tech 2 when any turbocharger system service has been performed. Certain enable criteria must be met for the ECM to perform this procedure.

The turbocharger learn procedure is required when the following service procedures have been performed:

• TC vane position control solenoid valve replacement
• TC vane position sensor replacement
• ECM replacement
• TC replacement
• Any service that disturbs the TC components