The turbocharges are maintained in the fully open position to minimize heat transmission from the exhaust gas to the turbocharges and to reduce the rate of gas flow through the particulate filter. This enables optimum heating of the particulate filter. if the driver demands a higher torque the turbochargers will respond by closing the vanes as required.
The throttle is closed as this assists in increasing the exhaust gas temperature and reducing the rate of exhaust gas flow, both of which increase the speed at which particulate filter is heated.
The exhaust gas recirculation (EGR) valve is closed as the use of EGR lowers exhaust gas temperatures and therefore makes it difficult to achieve the regeneration temperature in the particulate filter.
The glow plugs are sometimes activated to provide additional heat in raising the temperature of the particulate filter. To maintain flow plug serviceability the activation period of the glow plugs is restricted to 40 seconds