Charge Air Intake Valve (Where Fitted)
| ITEM | DESCRIPTION |
|---|---|
| 1 | Charge air recirculation solenoid |
| 2 | Charge air shut-off valve connecting rod |
| 3 | Vacuum connection |
| 4 | Vacuum actuator |
| 5 | Charge air outlet connection (to charge air coolers) |
| 6 | Charge air shut-off valve body |
| 7 | Charge air recirculation solenoid body |
| 8 | Charge air intake (from secondary turbocharger) |
| 9 | Charge air recirculation solenoid outlet connection (to primary turbocharger clean air duct) |
The charge air intake valve is attached to a bracket on the front subframe and the cooling pack protector. The ECM uses the valve to control the bi-turbocharger operation of the turbochargers.
The charge air intake valve consists of a recirculation solenoid and a shut-off valve that are connected together by four screws and a gasket. The charge air recirculation solenoid controls the flow of air from the compressor of the secondary turbocharger to the clean air duct of the primary turbocharger. The charge air shut-off valve controls the flow of air from the compressor of the secondary turbocharger to the charge air coolers.
The charge air recirculation solenoid is operated by a power feed from the EJB (Engine Junction Box) and a ground connection with the ECM. When it is de-energized, the charge air recirculation solenoid is closed.
If the charge air recirculation solenoid develops a fault it will default to the closed position. In this position an overspeed of the primary turbocharger will occur. This overspeed is sensed by the MAP (Manifold Absolute Pressure) sensor which detects the increase in pressure. The ECM registers the signals from the MAP sensor and operates the turbochargers in mono-turbo mode with restricted engine torque and DTCs (Diagnostic Trouble Code's) recorded.
The charge air shut-off valve is a flap valve operated by a vacuum actuator. The ECM operates the charge air solenoid to apply and release the vacuum in the actuator, which opens the valve when a vacuum is present. When the shut-off valve is open charge air from the secondary turbocharger flows through the valve to the charge air coolers in common with the air flow from the primary turbocharger.