BOX™ Aftertreatment Exhaust Flow
BOX (2V2) Aftertreatment Exhaust Flow
Aftertreatment Regeneration Strategy
Passive Regeneration
Passive regeneration occurs during normal operation when the engine is running at higher loads, which increases
exhaust temperatures. This process happens automatically during the normal operation cycle of the vehicle. The
operator will see no difference in vehicle performance or vehicle control.
Active Regeneration
DD13 and DD15
Active regeneration mode is controlled by Detroit Diesel Electronic Controls (DDEC). Two systems are used to
elevate the exhaust gas temperatures: Asymmetric Injection, and the Hydrocarbon (HC) fuel dosing system.
Asymmetric Injection is used to increase exhaust temperatures high enough to start the regeneration process.
Asymmetric Injection is only used on the DD13 and DD15 since these engines no longer have an Intake Throttle
Valve (ITV). Asymmetric Injection is not used for parked regenerations. It can be active in DPF zones 0-3, when
the engine is lightly loaded and above idle speed. Zone 4 has a 25% derate and usually requires a parked
regeneration.
Zone 5 is parked regeneration only due to the engine shut down feature. In DiagnosticLink®, check
“thermomanagement status”mode in the chart function. If it’s three, that indicates Asymmetric Injection is taking
place. Power delivery and fueling should vary seamlessly as driver load demand changes. A difference in engine
sound will be noticed when Asymmetric Injection is active, but is not an indication of issues.
Customer education will be necessary. An increase in vibrations up to 1.5 order of engine speed and 30 Hz can be expected. Noise,Vibration and Harshness (NVH) testing has shown that the engine and cab mounts have a larger impact on “driver touch” vibration reductions than the level of Asymmetric Injection.
Fuel is then injected into the exhaust by the hydrocarbon fuel dosing system. The injected fuel is oxidized in the
Diesel Oxidation Catalyst (DOC), elevating temperatures into the Diesel Particulate Filter (DPF) above passive
mode operating temperatures. At these temperatures, soot is regenerated faster than in the passive regeneration
mode.
The High Exhaust System Temperature (HEST) Lamp, located on the dash display, will only illuminate if
the vehicle speed drops below five miles per hour and the Selective Catalyst Reduction (SCR) outlet temperature
is above 525°C (977°F).”
DD16
Active regeneration mode is controlled by Detroit Diesel Electronic Controls (DDEC). Two systems are used to
elevate the exhaust gas temperatures: the intake throttle valve, and the fuel dosing system. The intake throttle
valve is actuated to increase exhaust temperatures high enough to start the regeneration process.
Fuel is then injected into the exhaust by the fuel dosing system. The injected fuel is oxidized in the Diesel Oxidation Catalyst (DOC), elevating temperatures into the Diesel Particulate Filter (DPF) above passive mode operating
temperatures. At these temperatures, soot is regenerated faster than in the passive regeneration mode.
The High Exhaust System Temperature (HEST) Lamp, located on the dash display, will only illuminate if the vehicle speed
drops below five miles per hour and the Selective Catalyst Reduction (SCR) outlet temperature is above 525°C
(977°F).
High Exhaust System Temperature (HEST) Lamp