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A I R M A N A G E M E N T S Y S T E M
OIL DRAIN TO PAN
VGT COIL
OIL TO OPEN
SIDE OF PISTON
OIL TO CLOSE SIDE
OF PISTON
OIL SUPPLY
CAM
FOLLOWER
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70
71
72
VGT Control Valve
• The VGT control valve is commanded by the
PCM, based on engine speed and load. The
magnetic field generated by this signal
moves a shaft in the control valve. This
movement meters engine oil through the
valve to either side of the piston. This design
feature reacts quickly to changes in demand
based on driving conditions. When one side
of the piston is pressurized, the opposite
side is vented.
• Depending on which side of the piston is
pressurized, the vanes either open or close.
A cam follower at the end of the valve
assembly provides feedback to the valve
allowing it to reach a neutral position during
times the vanes are not commanded to
move.
VGTCV Flows
• When the VGTCV is commanded to the full
open position, low or no duty cycle, oil from
the oil supply line is directed to the open
side of the actuator piston.
• Oil on the closed side of the piston is then
directed through the actuator piston, back to
the VGTCV, and then to drain.
• Note: If the VGTCV is disconnected the
valve will default to the open position.
• Once the desired turbocharger vane position
is obtained, the VGTCV goes to a neutral
position and both the open and closed sides
of the actuator piston is blocked off.
• When the VGTCV is commanded to the full
closed position, high duty cycle, oil from the
oil supply line is directed through the actua-
tor piston to the closed side of the piston.
• Oil on the open side of the piston is directed
back to the VGTCV and then to drain.
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