Energy Management, Function - GF54.10-P-0003GN
MODEL 166 as of model year 2016
MODEL 292
Block diagram, except model 166.063
Block diagram of model 166.063
Function requirements, general
- Terminal 30 ON
Energy management, general
Energy management manages the provision (supply) and consumption (management) of electrical energy with the aim of ensuring the startability of the engine and a stable supply to all electrical consumers.
Energy management specifies the 12 V on-board electrical system only. On hybrid vehicles (model 166.063) the correlation between the high and the 12-V on-board electrical system is also described. A comprehensive description of the high-voltage on-board electrical system is provided in the function description for the "Hybrid drive system".
The following components are involved in energy management:
- Battery sensor (monitoring of on-board electrical system battery charge level (G1))
- On-board electrical system battery (energy storage and supply when the engine is off)
- Additional battery (G1/7) (without CODE B03 (ECO start/stop function) and without CODE ME05 (HYBRID DRIVE 80KW-VARIANT (INCLUDING PLUGIN))) ("shift by wire" power supply when engine OFF)
- ECO start/stop function additional battery (G1/13) (with CODE B03 (ECO start/stop function) and CODE ME05 (HYBRID DRIVE 80KW-VARIANT (INCLUDING PLUGIN))) ("shift by wire" power supply when engine OFF and on-board electrical system power supply with automatic engine start)
- Voltage dip limiter (series resistor) at the positive terminal of the on-board electrical system battery (reduction in starting voltage dip) (with CODE 4U7 (Start/stop voltage dip fuse) and without CODE ME05 (HYBRID DRIVE 80KW-VARIANT (INCLUDING PLUGIN)))
- Alternator (energy generation)
- CDI control unit (on diesel engine) or ME-SFI control unit (on gasoline engine) (alternator management)
- SAM control unit (energy management master control unit) (with CODE B03 (ECO start/stop function))
- Power electronics control unit (with CODE ME05 (HYBRID DRIVE 80KW-VARIANT (INCLUDING PLUGIN))) (energy transfer from the high-voltage power supply for vehicle operation, energy transfer from the low-voltage network for charging the high-voltage battery)
Model 166.063
Because of the drive technology involved, hybrid vehicles are equipped with a high-voltage on-board electrical system.
The energy management module in the ME-SFI [ME] control unit regulates the energy flows in the high-voltage on-board electrical system along with the voltage conversion and energy exchange from and to the 12 V on-board electrical system.
To this end, the ME-SFI [ME] control unit communicates via the engine CAN, powertrain control unit, and hybrid CAN with the power electronics control unit and via the drive train LIN with the alternator. The 12 V on-board electrical system is supplied with energy primarily from the high-voltage on-board electrical system ("buck mode"). When the engine is off or in boost mode, the 12 V on-board electrical system is supplied with energy stored in the high-voltage battery and, when the vehicle is in operation, with energy generated by the electrical machine. If the energy made available by the power electronics control unit does not meet the existing energy requirements, the alternator will be switched on.
When outside temperatures are extremely low, the 12 V on-board electrical system is supplied with energy from the high-voltage on-board electrical system in order to safeguard the engine's starting capability ("boost mode").
- High-voltage battery module (energy storage and supply at engine OFF)
- Electric machine (high voltage on-board electrical system power generation)
- ME-SFI [ME] control unit (Energy management and alternator management)
- Battery management system control unit (monitoring of high-voltage battery charge level)
- Power electronics control unit (energy transfer from high-voltage, 12 V on-board electrical system and vice versa)
Energy management consists of the following subsystems:
- On-board electrical system management
- Major assemblies coordinator
On-board electrical system management
The on-board electrical system management monitors on-board power supply utilization and actively intervenes in the energy balance (e.g. consumer shutoff). The aim is to ensure the starting ability of the engine and a stable power supply to all electrical consumers.
The transport mode is activated in the production plant at the end of the production process, and it sets the overall vehicle into a defined special condition.
With targeted interventions in individual electronics systems the following is achieved:
- Reduction of shipping damage and accidents
- Best-possible charging of on-board electrical system battery through optimized energy management
- Avoidance of damage to and contamination of the vehicle interior as well as theft of loose parts from the vehicle interior
- Discontinuation of transport protection seal
The transport mode remains active on its way from the production plant to the dealers and company-owned sales and service outlets around the world up to the so-called delivery inspection and the final handover to the end customers.
The transport mode is automatically deactivated from a total distance traveled of more than 350 km whereupon it cannot be activated again. Up to this limit, the transport mode can be deactivated using the diagnostic system or key combinations at any given time and activated with the diagnostic system again. The fault memory is not actively deleted when the key combination is used for deactivation. This means that the "Transport mode active" fault entry remains stored. This must be deleted using the diagnostic system when the vehicle is inspected for the first time.
To support the processes in Sales and Logistics the vehicle's currently possible residual service life and, if necessary, appropriate care instructions for the on-board electrical system battery are shown on the multifunction display of the instrument cluster when the transport mode is active.
The on-board electrical system battery condition continuously determined by the on-board electrical system management is rendered fully transparent at any given time without the use of any additional measuring instruments during the vehicle delivery period. This display provides the operating personnel with specific instructions on what to do to guarantee a high delivery quality with regard to the on-board electrical system battery. The individual transport mode functionalities are split up for numerous individual systems. The core here is the central control of the transport mode by the on-board electrical system management. According to the on-board electrical system management specifications, targeted interventions (function restrictions or changes) are carried out in individual electronics systems.
The following function limits or modifications are implemented during the transport mode:
- Limitation of vehicle speed to 40 km/h
- Electric locking of front passenger and rear doors as well as liftgate
- Blocking roof opening function (with CODE 413 (Panoramic sliding sunroof))
- Monitoring of circuit 15 at standstill and acoustic feedback, when the vehicle is at a standstill for t > 10 s with the ignition switched on and the engine switched off
- Optimized quiescent current management, when the vehicle is parked for an extended period (e.g. transportation by ship)
- Limit exterior light functions
- Implement display on instrument cluster
- Adjust fault memory handling
The following tasks are implemented by the on-board electrical system management:
- Set specific consumer shutoff stages
- Optimized charging for on-board electrical system battery and additional battery:
- Activate fast battery charging
- Deactivate alternator management
- Deactivation of engine start/stop function (with CODE B03 (ECO start/stop function))
- Early opening of no-load current switch
- Limiting the reasons for closing circuit 30g relay
Display of the different "transport mode" system states in the multifunction display of the instrument cluster
Major assemblies coordinator
The major assembly coordinator is integrated into the CDI control unit or the ME-SFI [ME] control unit and forms the interface between the on-board electrical system management and the alternator. The CDI control unit or the ME-SFI control unit communicates with the alternator over the drive train LIN. The major assembly coordinator regulates the alternator's power output according to the on-board electrical system management specifications taking engine load into consideration.
The recording and evaluation of the relevant variables for this are conducted by the following components:
- SAM control unit
- CDI control unit or ME-SFI control unit
- Alternator
Energy management contains the following subfunctions, which are described in separate documents:
- Engine on energy management, function
- Engine off energy management, function
- Energy management for engine start/stop function (with CODE B03 (ECO start/stop function))
- DC/AC converter function (with CODE U80 (115 V socket))
The "energy management for engine start/stop function" subfunction is viewed from an energy management perspective. Information on the subfunction "Engine management for start/stop function" is documented in the function description "Common rail diesel injection (CDI), function" (with diesel engine) or "Gasoline injection and ignition system with direct injection, function" (with gasoline engine).
| Engine on energy management, function | GF54.10-P-1060GN | ||
| Engine off energy management, function | GF54.10-P-1050GN | ||
| ECO start/stop function energy management, function | MODEL 166 as of model year 2016 with CODE B03 (ECO start/stop function) MODEL 292 with CODE B03 (ECO start/stop function) |
GF54.10-P-1040GN | |
| DC/AC converter function | MODEL 166 as of model year 2016 with CODE U80 (115 V socket) MODEL 292 with CODE U80 (115 V socket) |
GF54.10-P-2005GN | |
| Overview of energy management system components | GF54.10-P-9990GN |