118 ENGINE COMPONENT AND LOCATION Manual Regeneration A procedure called "Manual Regeneration" can be used to regenerate the filters while they remain in the vehicle. The VCADS service tool or the Premium Tech Tool (PTT) can be used to perform this function. Discharge Recirculation Valve The Discharge Recirculation Valve (DRV) redirects some of the turbocharger output back through the turbocharger. This results in elevated exhaust temperature. The EECU uses this feature to maintain adequate exhaust temperature in support of active regeneration in the DPF system. Ultra Low Sulfur Diesel Fuel A catalyst works better the higher the temperature up to about 400°C (750°F).
Above this temperature, sulfur can become sulfuric acid. These filtering systems are practical only on vehicles that use ultra low sulfur fuels. It is required that diesel engines operating in conjunction with a DPF system use ultra low sulfur fuel that contains 15 parts per million (ppm), or less, of sulfur. WARNING The exhaust system reaches extremely high temperatures. Ensure that the system components are clear of all combustible materials. Ensure that personnel are aware that the surfaces are extremely hot. Failure to heed this warning may result in severe personal injury and property damage.