3–7
T-378
A manual regeneration can be initiated through the ECM Service tool. Refer to
The three phases of regeneration are explained below:
1. Passive Regeneration
Condition: Engine exhaust temperature is above 662°F (350°C).
Description: During Passive Regeneration, exhaust temperatures are hot enough to start an exothermic
reaction in the DOC without assistance. Only the DOC and DPF are required. Passive Regeneration
saves fuel by extending intervals between Active or Active Assist Regenerations.
2. Active Regeneration
Condition: Engine exhaust temperature is in range of 446° to 662°F (230° to 350°C).
Description: During Active Regeneration, fuel is injected into the exhaust system to raise exhaust tem
-
peratures hot enough to start a reaction in the DOC. Fuel is injected into the upstream pipe by the Doser
and then catalyzed in the DOC, which actively increases the exhaust temperature entering the DPF.
3. Active Assist Regeneration
Condition: Engine exhaust temperature is below 446° (230°C).
Description: During Active Assist Regeneration, the Air Control Valve (ACV) restricts engine air intake,
which changes the air-to-fuel ratio and increases the exhaust temperature entering the DOC. Once the
exhaust temperature reaches the level required for Active Regeneration, the Doser injects fuel into the
upstream pipe.
After regeneration is complete, the exhaust temperature will be allowed to return to its normal state. All
temperature data gets sent to the ECM. The ash that remains in the DPF after regeneration is only a fraction of the
original mass; the reduced mass allows back pressure to return to near non-EES values. However, as ash
continues to accumulate in the DPF, the base back pressure will continue to rise. Refer to Maintenance Schedule,
, to see intervals for cleaning DPF.
3.8 System Specifications
Table 3–1 System Specifications
Component
Specifications
Fuel Pump
12V, 7.5 Amp max draw
1.6 ohms @ room temperature
ECM Service Tool: “D06 Fuel Pump” test mode
Air Control Valve (ACV)
ACV Connector:
Pin 1: 5V
Pin 2: Signal (PWM)
Pin 3: Sensor -
Pin 4: Motor +
Pin 5: Motor -
ECM Service Tool: “Do1 ACV” test mode
Fuel Injector (Doser)
Coil resistance: 12V, 1.2 ohms @ 77°F (25°C)
ECM Service Tool: “DO2 Injector” test mode
Fuel doser current draw is outside the acceptable range of 0.5 -
6.5A for five seconds when energized.
Temperature Sensors:
ESEIT, ESFIT, ESFOT
Range, cont: -40°F to 1382°F (-40°C to 750°C)
Resistance: 230 ohms (RT)
Fail shorted: -148°F (64°C)
Fail opened: >2012°F (1100°C)
