CL 600 (140.076) V12-6.0L (120.982) (1998)
Idle Speed: Description and Operation
ME-SFI Idle Speed Control Function
ENGINE 120.982 /983
B11/10
Right ECT sensor
B37
Pedal value sensor
M16/3
Right EA/CC/ISC actuator
M16/4
Left EA/CC/ISC actuator
N3/11
Left ME control module
N3/12
Right ME control module
CAN
Controller Area Network (databus)
d, e
Idle throttle information
Task
Controlling idle speed in the case of
- different engine loads, e.g. power steering turned to full lock, engaging Drive position, switching on AC compressor
- different mixture, e.g. from activated charcoal canister if purging activated (depending on activated charcoal charge)
Operation
The EA/CC/ISC actuator controls the idle speed by altering the position of the throttle valve. It is actuated by the ME-SFI control module.
The right ME control module (N3/12) operates the throttle valve actuator motor (M16/3m1) in line with the input signals at the right ME control module
(N3/12) and at the same time transmits information via the CAN databus to the left ME control module (N3/11), which thereupon operates the left
throttle valve actuator motor (M16/4m1).
Idle speed information is exchanged between the ME control modules over two cables. If the CAN databus fails, the idle speed is thus regulated.
Heating-up speed
In order to warm up the catalytic converter more rapidly to its operating temperature, engine speed is increased for about
20 seconds to approx. 1110 - 1500 rpm at coolant temperatures of
< 40 °C each time the engine is started with the selector lever in position P/N. When a Drive position is engaged, engine speed is immediately controlled
to a lower value.