LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Mercedes Benz >> 2018 >> S450 Base >> Repair and Diagnosis (Single Page) >> Electrical >> Charging Systems >> Electrical System, Equipment & Instruments - 222 Chassis (02 Of 10) >> Basic Knowledge >> Component Description For DC/DC Converter Control Unit >> Component Description For DC/DC Converter Control Unit - GF54.10-P-3006LFH
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Component Description For DC/DC Converter Control Unit - GF54.10-P-3006LFH

Model 222.163 with engine 276 

Model 222.173 with engine 276 

G15400643Courtesy of MERCEDES-BENZ USA

Shown: Model 222.163 

The DC/DC converter is located in the trunk under the load compartment cover.

Design of DC/DC converter control unit 

G15400644Courtesy of MERCEDES-BENZ USA

Task 

General 

The DC/DC converter control unit enables energy to be exchanged between the high voltage on-board electrical system and the 12 V onboard electrical system, by transforming the high voltage direct voltage (primary voltage) into 12 V direct voltage (secondary voltage).

IMPORTANT Interlock circuit

The interlock circuit is used as contact protection to protect people against inadvertent contact with high-voltage components. The interlock is an anticipatory contact which opens a little before the high-voltage connection when opening a high-voltage connection. In this way timely discharging of the high voltage intermediate circuit is achieved by the control units of the high-voltage components.

In order to do this, a 12 V/88 Hz interlock signal is looped through all high voltage on-board electrical system assembly parts that can be removed or opened. To do this there is an electrical bridge in each removable high-voltage connection which interrupts the interlock circuit during removal of the high-voltage connection. The interlock circuit is also led switched in a series over the 12 V control units plug connection of the high-voltage components.

CAN network 

The charger is connected to the vehicle CAN network via the hybrid CAN (CAN L) and exchanges data with other control units.

Input and output signals 

Input factors and output factors for the following components are read in and output over direct lines by the DC/DC converter control unit:

Input factors over a direct line Initial parameters over a direct line Supplemental information
Circuit 15 - -
Circuit 30c (crash signal from rear pre-fuse box (F33) - -
Circuit 30 - -
Circuit 31 - -
Interlock circuit Interlock circuit -

The following components are connected to the DC/DC converter control unit through power connections:

Output connections + Output connections - Supplemental information
Battery management system control unit high-voltage connection (N82/2) Battery management system control unit high-voltage connection (N82/2) -

Input factors and output factors for the following control units are sent or received by the DC/DC converter control unit over the CAN:

Input factors via hybrid CAN (CAN L) Output factors via hybrid CAN (CAN L) Supplemental information
Battery management system control unit (N82/2) Battery management system control unit (N82/2) -
Charger (N83/5) Charger (N83/5) -
Powertrain control unit (N127) Powertrain control unit (N127) Contains signals of further control units which are connected via the CAN network.
Power electronics control unit (N129/1) Power electronics control unit (N129/1) -
  Wiring diagram for DC/DC converter control unit   PE54.10-P-2105-97SEA