Turbocharger - Vehicles With INGENIUM I4 2.0L Diesel 240PS Engine

WARNING: This page is about a different variant/trim than selected.

The exhaust gas emitted from the cylinder head flows into the exhaust manifold first. Distribution of the exhaust gas between the High Pressure (HP) Variable Geometry Turbocharger (VGT) and the Low Pressure (LP) turbocharger is controlled by a bypass valve. The operation of the bypass valve is based on engine speed and controlled by the Powertrain Control Module (PCM).

Below 1500 RPM, when the exhaust gas flow rate is low, the bypass valve remains completely closed. The entire exhaust gas flow is diverted into the HP VGT. Boost pressure is controlled by varying the HP VGT vane actuator, this results in a very quick and high boost pressure rise.

The exhaust gas flow that exits the HP VGT is passed over the LP turbocharger. This provides sufficient gas flow to start the LP turbocharger, which becomes primed to deliver boost pressure without any lag.

As the engine speed increases between 1500 and 2800 RPM, the flow capacity of the high pressure stage is increasing as the HP VGT is opened. As the maximum capacity is exceeded, the HP VGT bypass valve is partially opened. This allows more from the exhaust gas to bypass the HP VGT into the LP turbocharger.

At high engine speeds and loads the majority of the exhaust gas is bypassed around the HP VGT into the LP turbocharger through a bypass valve. The bypass valve automatically opens as the LP stage boost pressure exceeds the HP stage boost pressure. The completely open bypass valve allows the full flow of exhaust gas through the LP turbocharger, generating maximum power output.

At maximum engine speeds and loads the LP turbocharger speed is limited by bypassing exhaust gas around the LP turbocharger. At this stage the total boost pressure is regulated by the LP turbocharger wastegate valve.

The air intake to the LP turbocharger receives air from the Exhaust Gas Recirculation (EGR) system. For additional information, refer to: ENGINE EMISSION CONTROL

The intake air is drawn through the LP turbocharger and then passed onto the HP VGT.

As the engine speed rises, more intake air is getting compressed by the LP turbocharger and supplied onto the VGT, which compresses the air further. This increases the boost pressure and charge air density.

At maximum engine speed the increased air pressure opens the passive compressor bypass valve, which prevents air recirculation through the LP turbocharger and is allowing more air flow.