CL 550 4MATIC (216.386) V8-5.5L (273.961) (2009)
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EIS [EZS] control unit (N73)
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Start enable request (drive authorization system)
Fuel pump control unit (N118)
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Diagnosis requests
Design
The housing for the ME-SFI [ME] control unit is made out of diecast aluminum and the cover is made out of corrosion-proof sheet steel. The ME-SFI
[ME] control unit is protected against water and dusts. The housing contains the 32-bit measuring and control electronics for the engine control.
Voltage supply
The ME-SFI [ME] control unit is "circuit 30 secured" and also supplied with voltage for ignition ON by "circuit 87 M4".
It is fitted in the operating voltage range with short-circuit protection as well as reversed polarity protection.
Voltage is supplied through several pins connected in parallel to relieve the electrical connectors.
Ground connection
The "circuit 31" ground link consists of several ground lines from electronic ground (LH footwell) ( W34/1).
Computer run-on
If the ME-SFI [ME] control unit receives the signal "circuit 15 OFF" a processor run-on of approx. 5 seconds is started.
However, it may also last for several minutes due to various functions (for example, on-board diagnosis (OBD), drive authorization system (DAS),
thermal management).
Assembly operations
Ensure before unplugging the plug on the ME-SFI [ME] control unit that the ignition is switched off and computer run-on has ended. This is to prevent
damage to the ME-SFI [ME] control unit and save errors in the control units linked to the CAN.
Variants
The engine control variants, such as country and exhaust gas variants, are activated with the Diagnosis Assistance System (DAS) using the variant coding
function.
Replacement of the ME-SFI [ME] control unit is not necessary.
