4.25
EFI / Ignition Systems
4
Rev. 1 07/2006
Wastegate Solenoid Pulse Valve Circuit (FST
Only)
The wastegate solenoid pulse valve allows the ECU to control
the amount of boost pressure within the induction system. Boost
control is accomplished by pulsing the valve at different
frequencies depending on the amount of boost pressure within
the induction system. If the ECU determines that the targeted
boost pressure has been obtained, the ECU will trigger the pulse
valve so that a certain level of compressor pressure is routed to
the wastegate actuator. Doing so activates the wastegate so that
a proportion of exhaust gas bypasses the turbine.
In the event that power to the wastegate solenoid is lost, the
solenoid defaults so that all of the compressor pressure is routed
to the wastegate actuator. When this occurs, maximum boost
pressure will be limited to the wastegate’s internal spring pop-
off pressure of 6 - 6.5 lbs. (413 - 448 milliBAR)
The wastegate solenoid is located on the front of the air box next
to the turbocharger.