C15 and C18 – Clean Emissions Module Aftertreatment Fuel System


(6) ARD head

(7) Pilot fuel line

(8) Main fuel line

(17) ARD fuel manifold

(18) Electric priming pump

(19) Primary fuel filter

(22) Fuel tank

(23) Pilot fuel connection

(24) Main fuel connection

(25) Main fuel pressure sensor

(26) Pilot fuel pressure sensor

(27) Main fuel solenoid valve

(28) Pilot fuel solenoid valve

(29) ARD manifold fuel filter fitting


Illustration 9 g02438136
(30) Diverter valve

(31) Fuel pressure regulator

Electric priming pump (18) is energized when regeneration is desired. Electric priming pump receives power from the battery. A relay is used to control power to the electric priming pump. The engine ecm sends a signal to the relay when regeneration is desired. When the relay is energized, battery power is sent to the electric priming pump. Electric priming pump pulls fuel from fuel tank (22) through the 10 micron primary fuel filter. Once fuel has exited the pump, the pressure regulator (31) regulates the pressure to 1900 kpa (275 psi). The fuel diverter valve (30) is de-energized during regeneration. When the fuel diverter valve is de-energized, all fuel flow from the electric priming pump is sent to the ARD system. The engine will still be receiving fuel drafted from the fuel tank that bypasses the electric fuel pump when the diverter valve is de-energized. When the fuel diverter valve is energized, all fuel is sent to the engine and no fuel is sent to the ARD system. The fuel diverter valve is energized during engine priming.


Illustration 10 g02436260
Front view

(30) Diverter valve

(32) Fuel flow to engine (diverter valve energized)


Side view

(30) Diverter valve

(33) Fuel flow to CEM (diverter valve de-energized)

Once fuel flow exits the pump housing, the fuel enters the ARD fuel manifold (17) . As fuel enters the ARD fuel manifold, fuel is filtered by a stainless steel sintered filter. This filter can filter down to 40 micron. This filter is designed to collect any debris that may have entered the system during servicing.

As fuel flow continues through the ARD fuel manifold, the fuel takes a parallel flow path. One path goes to the pilot fuel solenoid valve (28) and another path goes to the main fuel solenoid valve (27) . The pilot and main fuel solenoid valves are pulse width modulated solenoid valves controlled by the engine ECM. The pilot fuel solenoid valve is considered the primary fuel valve. Once the pilot fuel solenoid valve is fully open and more fuel is still desired, the main fuel solenoid valve will open. Once the fuel has passed through the pilot and main fuel solenoid valves, the fuel pressures are measured by a sensor for each circuit. When the circuit is operating in closed loop mode, the ECM uses these pressure signals to determine the proper amount of fuel. The amount of fuel is delivered to achieve the desired DPF inlet temperature.

Once the fuel exits the fuel manifold, the fuel enters the ARD head (6) . The ARD head contains a single connection for pilot fuel (23) and a single connection for main fuel (24) . These connection fittings contain 40 micron sintered filter media. These filter fittings provide for protection against debris that may be introduced during servicing. As the fuel continues into the ARD head, the fuel opens two drain check valves. There is a drain check in the pilot fuel passage and the main fuel passage. These drain checks keep fuel trapped between the ARD fuel nozzle and pilot/main fuel valves when the system is not being used.

Next, the fuel enters the fuel nozzle. The fuel nozzle contains two separate passages for pilot fuel and main fuel. The fuel nozzle also contains a heating element. The heating element is used to clean accumulated carbon deposits from the end of the fuel nozzle. The heating element is powered through a solid-state relay mounted on the CEM electronics panel. The engine ECM periodically sends a signal to the relay causing battery voltage to travel to the heating element and energizing the coil. The coil can reach temperatures as high as 550° C (1022° F) to clean off carbon deposits.

In order for the heater cycle to run the following parameters must meet minimum requirements: battery voltage, engine coolant temperature and engine speed. The heated nozzle cycle runs for 60 minutes once the cycle is triggered. Many factors determine when to trigger a heater cycle. The two main factors are time between heater cycles and DPF regeneration completions. The first trigger is when the time between heater cycles has reached 7.5 hours and has successfully completed a DPF regeneration. Another trigger is at 15 hours between heater cycles and a number of tries to complete a DPF regenerations have been attempted. The third trigger is 20 hours between heater cycles. Other factors that have an impact to when the heater cycle will run are, the amount of fuel that has flown through the nozzle and time between DPF Regenerations.


Illustration 12 g02436261
(34) Pilot drain check valve

(35) Main drain check valve

(36) Fuel nozzle

(37) Heating element

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