Deep Discharge Protection, Basic Function - GF54.10-P-1012A
Model All (4xWD)
Model All (CAR)
Overview
This document contains information on:
- General
- Function
- Hardware reset
- Quiescent current shutoff (except vehicles with interior protection)
- Idle state
General
Deep discharge protection prevents excessive discharging of the on-board electrical system battery when the vehicle is parked (rest phase). This ensures that vehicle mobility is retained over a long period of time or at increased no-load currents. Hardware resets mean that increases in quiescent currents caused by faulty components are minimized.
Function
Hardware reset
If the energy management detects an increased quiescent current, it attempts to reset the reason causing it by disconnecting the on-board electrical system battery from the on-board electrical system. All consumers on circuit 30t are disconnected from the power supply. After a defined period of time, the on-board electrical system battery is connected again to the on-board electrical system. All consumers on circuit 30t are then supplied with voltage again. If the required affect is not achieved a hardware reset is repeated a maximum of two times. If the quiescent current is still too high, the on-board electrical system battery remains connected to the onboard electrical system. The effect of the increased quiescent current is to discharge the on-board electrical system battery.
The following events prevent a hardware reset:
- Head unit was activated by the user
- Circuit 15R ON or higher
- Hazard warning flasher function active
- Anti-theft alarm system alarm active (vehicles with ATA)
- Panic alarm active (vehicles with panic alarm function)
- External charging
- Parking lights function active
- Climate control active
- Evaporator drying active
- Quiescent current measurement active
- Residual heat utilization active
- Recharging process through DC/DC converter (vehicles with 48 V technology, hybrid vehicles and electric vehicles)
- Production or transport mode active
Quiescent current shutoff (except vehicles with interior protection)
The quiescent current shutoff prevents deep discharge of the on-board electrical system battery. If the charge level of the on-board electrical system battery drops below 40 %, the energy management disconnects the on-board electrical system battery from the on-board electrical system. Before this, the energy management sends a signal over networking as advance notice of the shutoff. This signal is relevant for all control units that are supplied with voltage via circuit 30t. All consumers on circuit 30t are disconnected from the power supply. The on-board electrical system battery then remains permanently disconnected from the on-board electrical system.
The following events prevent the on-board electrical system battery being disconnected from the on-board electrical system:
- Change in circuit status (circuit 15R ON or circuit 15 ON)
- Hazard warning flasher function active
- Anti-theft alarm system alarm active (vehicles with ATA)
- Panic alarm active (vehicles with panic alarm function)
- External charging
- Quiescent current measurement active
In vehicles with electromechanical brake booster, the brake control system also prevents disconnection of the on-board electrical system battery by means of an electric lock.
Increased quiescent currents owing to active applications or functions (e.g. evaporator drying, run-on times, stationary heater, seat adjustment, display calibration) are permitted and do not lead to the on-board electrical system battery being disconnected from the on-board electrical system.
The on-board electrical system battery is switched on again when one of the following events occurs:
- Unlocking of vehicle through central locking system
- Change in circuit status (circuit 15R ON or circuit 15 ON)
- Diagnosis requests
Idle state
The quiescent state is activated via the multimedia system. All electrical consumers that are supplied with voltage through circuit 30t are switched off 5 minutes after the ignition is switched off. The multimedia display then shows the remaining service life in weeks and the current charge level of the on-board electrical system battery. If the quiescent state cannot be started, the message "Function not available!" appears (the charge level of the on-board electrical system battery does not permit the function). When in quiescent state, the vehicle can be parked for am extended period without any energy loss. The on-board electrical system battery is preserved. The interior protection (vehicles with interior protection) is then not active. Connections to online services are also not possible. If the displayed remaining service life is exceeded, the on-board electrical system battery may need to be charged. The quiescent state is deactivated by switching on circuit 15.
| Function schematics | |||
| Quiescent current management, function schematic | Model 118, 177, 243, 247 Model 167, 293 Model 213, 238, 257, 290 as of model year 2021 | PE54.10-P-2502-97A | |
| Model 223 | PE54.10-P-2502-97B | ||
| Model 192, 206, 214, 232, 236, 254 | PE54.10-P-2502-97C | ||
| Model 294, 295, 296, 297 | PE54.10-P-2502-97D | ||
| Model 464 | PE54.10-P-2502-97E | ||
| Additional basic functions | |||
| Battery sensor, basic function | GF54.10-P-2009A | ||
| On-board electrical system battery, basic function | GF54.10-P-2011A | ||
| Basic function of signal acquisition and actuation module | Model 118, 177, 243, 247, 464 | GF54.21-P-9895A | |
| Basic function of signal acquisition and actuation module at front | Model 167, 192, 206, 214, 223, 232, 254, 293, 294, 295, 296, 297 Model 213, 238, 257, 290 as of model year 2021 |
GF54.21-P-9896A | |
| Electronic ignition lock control unit, basic function | GF80.57-P-9890A |