Turbocharger (G2006270): Overview

The TDV6 3.0L diesel engine uses two turbochargers: The Variable Geometry Turbocharger (VGT) which is the primary turbocharger and a fixed vane turbocharger which is the secondary turbocharger. The VGT is fitted to the Bank 2 exhaust manifold and the fixed vane turbocharger is fitted to the Bank 1 exhaust manifold.

Both turbochargers are used in a parallel sequential turbocharging system. This enables the engine to achieve quick throttle response at low engine speeds and efficient use of exhaust gas energy at high engine speeds. The primary turbocharger operates through the entire engine speed range, and is most efficient at engine speeds of up to 2800 RPM while running in mono turbocharger mode. At engine speeds above 2800 RPM under load, the secondary turbocharger comes into operation, with both of the turbochargers running in a parallel bi-turbocharger mode.

The bi-turbocharger system comprises of:

• Variable Geometry Turbocharger (VGT) - Primary turbocharger
• Fixed vane turbocharger - Secondary turbocharger
• Turbine intake shut-off valve (TSOV)
• Charge air intake valve which incorporates the charge air recirculation valve and the charge air shut-off valve

The operation of the bi-turbocharger system is controlled by the Powertrain Control Module (PCM).