Boost Control Solenoid

Boost Control Solenoid (BOOST):

PURPOSE
The Boost Control Solenoid (BOOST) controls turbocharger boost pressure by regulating the boost signal to the wastegate actuator.

LOCATION
Beneath turbocharger assembly.

OPERATION
Under low to medium speed, the ECA allows full boost if available, and opens the wastegate solenoid valve fully, venting boost pressure to the compressor inlet. This leaves insufficient pressure to move the actuator; the wastegate remains closed and full boost is available.

As load and speed increase, boost pressure reaches its limit and the ECA will gradually close venting of boost pressure to the compressor inlet. This increases pressure to overcome the actuator spring, so the actuator begins to push the wastegate open. This continues until the solenoid valve is closed and the wastegate is fully open.