GF54.10-P-2002RIT Consumer Shutoff Function
GF54.10-P-2002RIT Consumer Shutoff Function
- with CODE (P99) Special model "AMG Black Series"
General function requirements
^ C. 30 ON
Consumer shutoff, general
In order to prevent complete discharge of the on-board electrical system battery (G1) in all driving cycles, the on-board electrical system voltage is continuously monitored and evaluated by the vehicle power supply control unit (N82/1). The operating rate of the alternator (G2) is also monitored.
As soon as the alternator is no longer able to provide the requested electrical output, the consumer shutoff function is activated. The consumer shutoff function is also referred to as dynamic load management.
The on-board electrical load is reduced by cutting back convenience functions. This avoids a negative charge balance and ensures that starting ability is preserved.
The consumer shutoff function is canceled when the alternator is again able to provide the requested electrical output to stabilize the on-board electrical system voltage.
The requests for consumer shutoff are issued by the vehicle power supply control unit in succession via the interior CAN (CAN B).
The following control units are thus requested to shut off or reduce the consumption of consumers:
- Instrument cluster (A1)
- PSE controller unit with combined functions (A37)
- COMAND operating, display and controller unit (A40/3)
- Rear SAM control unit (N10/8)
- Driver-side SAM control unit (N10/10)
- Right SAM control unit (N10/11)
- AAC [KLA] control and operating unit (N22)
- Left front seat adjustment control unit with memory (N32/1) (with code (494) USA version)
- Right front seat adjustment control unit with memory (N32/2) (with code (494) USA version)
- Left door control unit (N69/1)
- Right door control unit (N69/2)
- Keyless-Go control unit (N69/5) (with code (889) Keyless-Go)
- Overhead control panel control unit (N70)
- EIS [EZS] control unit (N73)
- Central gateway control unit (N93)
The EIS [EZS] control unit forwards this request via the engine compartment CAN (CAN C) to the ME-SFI [ME] control unit (N3/10).
The central gateway control unit forwards this request over the engine compartment CAN to the ESP, SPS [PML] and BAS control unit (N47-5).
The consumer shutoff function sequence consists of the following subfunctions:
^ Consumer shutoff with engine running function sequence (emergency mode)
^ Consumer shutoff with engine OFF function sequence (emergency starting mode)
^ Consumer cut-in function sequence
Additional function requirements for consumer shutoff with engine running (emergency mode)
^ Circuit 61 ON
The status of circuit 61 is placed on the interior CAN by the passenger-side SAM control unit.
Consumer shutoff with engine running function sequence (emergency mode)
Consumer shutoff in emergency mode is subdivided into the following three stages:
- Shutoff stage 1: U < 10.6 V at the on-board electrical system battery
- Shutoff stage 2: U < 10.2 V at the on-board electrical system battery
In shutoff stage 1, the following functions are shut off depending on the vehicle equipment:
- Wiper park position heater (R2/10)
- Steering column tube adjustment
- Heated rear window (R1)
- Interior illumination
- Ventilation control of air conditioning system
The following components are actuated at reduced power output:
- Blower motor (A32m1) with P < 69 %
- Telematics (current limited to I = 11 A)
Corresponding fault messages are issued by the battery symbol lighting up in the left multifunction display (A1p13) and by display of the text "Electrical consumers shut off." in the right multifunction display (A1p15).
The following consumers are additionally switched off during shutoff stage 2:
- Mirror heater (M21/1r1 and M21/2r1)
- Inside rearview mirror unit (A67)
The following component is actuated at reduced power output in shutoff stage 2:
- Blower motor with P < 53 %
The fault messages in the multifunction displays of the instrument cluster remain unchanged.
Additional function requirements for consumer shutoff with engine OFF (emergency starting mode)
^ Circuit 15C ON
^ Circuit 61 OFF
The circuit status of circuit 15 is made available by the EIS [EZS] control unit on the interior CAN.
The status of circuit 61 is placed on the interior CAN by the passenger-side SAM control unit.
Consumer shutoff with engine OFF function sequence (emergency starting mode)
If the on-board electrical system voltage drops to a value of U < 10.8 V, the consumer shutoff is activated when the circuit status changes from circuit 15C ON to circuit 15R ON after a waiting period of t = 30 s. In emergency starting mode the consumers of shutoff stages 1 and 2 are switched off.
Consumer cut-in function sequence
When the voltage of the on-board electrical system battery ha stabilized at U > 12.5 V, the consumer shutoff is canceled after a delay.
