PIPE 0878508 - Caterpillar

Exhaust AirExhaust air flows from the turbine housing to the ARD body. The exhaust air then flows through the Diesel Oxidation Catalyst (DOC) and the DPF. The exhaust air then exits through the muffler (if equipped).Combustion AirThe air used to supply the ARD head is taken from the turbocharger compressor outlet. The pressure of this air is measured at the inlet to the ARD combustion air valve by the combustion air inlet pressure sensor. The air is then metered by the ARD combustion air valve. The ARD combustion air valve contains a DC motor and analog position sensor. The ARD combustion air valve is commanded via the ARD air valve controller. The ARD air valve controller communicates via J1939 datalink with the engine ECM. The ARD air valve controller sends the air valve position signal to the engine ECM. The engine ecm then sends a desired valve position to the ARD air valve controller. The ARD air valve controller processes the desired valve position command into a % current command to the ARD combustion air valve. The ARD combustion air valve moves the desired amount and the new valve position is transmitted back to the ARD air valve controller.
Illustration 14 g02436316
(13) ARD air valve controller
(14) ARD combustion air valve
(22) Electronic Control Module (ECM)
(43) Desired position command through J1939
(44) Bi-directional current to