Function of injection system: - ra07216020f10x(0010)

WARNING: This page does not describe the selected car, but rather 42 other vehicles, including the 1999 Mercedes-Benz S600, 1999 Mercedes-Benz S500, 1999 Mercedes-Benz S420, 1999 Mercedes-Benz S320, and 1999 Mercedes-Benz CL600. However, it is still accessible from the selected car via links, so may be relevant.

U. Electronic diesel system (EDS) F. Exhaust gas recirculation (ARF) Engines 602.96, 603.96/97 Turbo

U. Electronic diesel system (EDS)

f) Exhaust gas recirculation (ARF)
Exhaust gas recirculation is initiated as soon as the following conditions are met:
- Coolant temperature between 60°C and 110°C
- Engine speed between idle and 2800/ min or 3500/min on Engine 602.962 from Model Year 1990
- Engine speed up to approx. 3500/min as of Model year 1992, Engines 602.96, 603.96 and 603.971
- Control rod travel less than 9 mm
- Battery voltage 11-14 Volt

Depending on the input signals of the sensors e.g. control rod travel, engine speed etc., the EDS control unit determines the matching quantity of recirculated exhaust gas for each operating state. The vacuum transducer is energized and supplies the corresponding vacuum to the ARF valve.

The ARF quantity is reduced as engine load and speed increase. This means Increase in the control current=increase in ARF quantity.

Reduction in control current=reduction in ARF quantity.

Additionally as of Model Year 1992 : ARF shutoff at 10° before full load by means of microswitch of accelerator control and switchover valve in vacuum line. This reduces smoke emissions during load change in full load direction.

NOTE: Temperature and engine speed are dependent on the control unit version. Refer to test routine for exact data.

Block diagram ARF up to Model Year 1991 (inclusive)

Fig 1: Block Diagram ARF Up To Model Year 1991 (Inclusive)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Block diagram ARF as of Model Year 1992

Fig 2: Block Diagram ARF As Of Model Year 1992

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

The ARF system with vacuum transducer, switchover valve (as of Model Year 1992), ARF valve, air flow sensor and EDS control unit operates as a closed control loop.