Exhaust Gas Recirculation (EGR)

EGR system is controlled by engine control module. The engine control module processes engine speed, air mass, and engine coolant temperature to control EGR. When closed throttle position contact is open and coolant temperature is more than 118°F (48°C), EGR switchover valve receives an activation signal from engine control module. See Figure .

Fig 1: Cruise Control/Idle Speed Control Module Block Diagram (HFM-SFI Equipped Vehicles)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA

Fig 2: Electronic Accelerator Control Module Block Diagram (HFM-SFI Equipped Vehicles)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA

Fig 3: Locating HFM-SFI System Components (S320 - 1 Of 3)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA

Fig 4: Locating HFM-SFI System Components (S320 - 2 Of 3)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA

Fig 5: Locating HFM-SFI System Components (S320 - 3 Of 3)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA