Function of engine overload protection (not for engines with P2 control) - ra09006020200x(0200)

Engines 602.96, 603. 96/97 TURBO in Models 124, 126, 140, 201 (Model 463.3 : for deviations see introductory notes) 

A pressure switch is installed in the charge air pipe as an overload protection of the mechanical parts of the engine. In the event that the charge pressure rises to above 1.1 ± 0.15 bar gauge pressure, air is admitted to the ALDA unit through the switchover valve and the fuel quantity is limited to that of a naturally aspirated engine.

Fig 1: Charge Air Pressure - Full Load Graph

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Location of Components 

Fig 2: Identifying Injection Pump, Governor, Fuel Pump And Vacuum Control Valve

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Fig 3: Identifying Engine Overload Protection Switchover Valve

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Fig 4: Identifying Engine Overload Protection Switch

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Pressure, vacuum diagrams (refer to 07.1-0500).

Wiring diagrams (refer to 07.1-0400).