S 350 (140.134) L6-3.5L DSL Turbo (603.971) (1995)
Idle Speed: Description and Operation
Block Diagram, Electronic Idle Speed Control (ELR)
The starter ring gear speed sensor (L3) picks up the engine speed (144 impulses per revolution) and sends it in the form of an AC voltage signal to the
EDS control unit. The EDS control unit processes the rpm signal and performs a nominal/actual value comparison.
As a result, the idle speed is held constant by the electromagnetic actuator regardless of engine load. At coolant temperatures below 60 °C, the idle speed
nominal value is increased according to a preset reference map.