Engine On Energy Management, Function - GF54.10-P-1060GW
Model 463
as of Model year 2013
Function requirements, general
- Signal "engine running" set
Model 463 (except 463.342) as of Model year 2013 up to Model year 2019
Model 463.342
as of Model year 2013
The CDI control unit (N3/9) (diesel engine) or the ME-SFI [ME] control unit (N3/10) (gasoline engine) sends the "Engine running" or the "Drive train operational" signal over the chassis CAN 1 (CAN E1), electronic ignition lock control unit (N73) and the interior CAN (CAN B) to the SAM control unit (N10).
On vehicles with engine 176, the ME-SFI control unit sends the "engine running" or "Drive train operational" signal via the drive train CAN (CAN C), powertrain control unit (N127), chassis CAN 1, electronic ignition lock control unit and interior CAN to the SAM control unit.
Model 463 (except 463.342) as of Model year 2019
The CDI control unit (diesel engine) or the ME-SFI [ME] control unit (gasoline engine) sends the "Engine running" signal over the drive train CAN (CAN C1), powertrain control unit, suspension FlexRay (Flex E), electronic ignition lock control unit and the interior CAN to the front SAM control unit (N10/6).
Engine on energy management, general
Engine on energy management ensures the stability of the on-board electrical system as well as an even charge balance in the on-board electrical system battery (G1).
If lots of electrical consumers are operated simultaneously, overload situations may occur, which have to then be buffered by the on-board electrical system battery. If such an overload situation lasts for an extended period or if the charging capacity of the on-board electrical system battery is low, a negative charge/discharge ratio could arise. In such an instance, the mobility and the stable supply of all electrical consumers can no longer be assured. In situations where the on-board electrical system is overloaded for prolonged periods, the engine ON energy management increases the power output of the alternator (G2).
The energy management also reduces the comfort consumers to enable an equalized charge balance for the on-board electrical system battery to be achieved.
Energy management for driving encompasses the following sub-functions:
- Voltage provision
- Dynamic idle speed control
- Consumer reduction (deactivation of comfort functions)
- Power supply via additional battery (G1/7) (up to production date April 2nd, 2018 or Model 463.342, except code MJ7 (ECO start/stop function))
The no-load current shutoff can also be triggered manually via a corresponding menu in the head unit (rest mode). In this case, all electrical consumers that are supplied with voltage via circuit 30t are switched off 15 min after the ignition is switched off. The remaining service life in weeks is then shown in the Audio/COMAND display (A40/8). If the rest mode cannot be started due to an active fault, the message "Function not available!" appears. If the rest mode cannot be started due to the charge level of the battery, the message "Charge level too low for rest mode" appears.
The head unit sends the "Activate rest mode" request via the user interface CAN, electronic ignition lock control unit and interior CAN to the front SAM control unit, which then starts the no-load current shutoff. The front SAM control unit then sends information for displaying the remaining service life or for outputting the message via the interior CAN, electronic ignition lock control unit and user interface CAN to the head unit. The head unit then actuates the display in the Audio/COMAND display via the high-speed video link signal line.
Model 463 (except 463.342) with transmission 725 as of Model year 2019
To enable selector lever position "P" to also be engaged when the onboard electrical system is overloaded, the electronic ignition lock control unit is also supplied with voltage through the park pawl capacitor (C8).
Voltage provision
The voltage provision function comprises the following sub-functions:
- Determination of charge level of on-board electrical system battery
- Charge on-board electrical system battery
- Alternator regulation (alternator management)
Determination of charge level of on-board electrical system battery
The state of the on-board electrical system battery is recorded by the battery sensor (B95). This calculates corresponding parameters on the voltage, current and temperature measurements on the on-board electrical system battery. The charge level of the on-board electrical system battery is the ratio of the current charge to the maximum storable charge. This is based on the calculation of the internal resistance of the on-board electrical system battery. This, along with the battery capacity, is then used to compute the charge stored in the on-board electrical system battery.
For vehicles as of production date April 3rd, 2018 except Model 463.342 the following applies:
The front SAM control unit reads in the data of the battery sensor over the battery sensor LIN (LIN B15), it also measures the voltages at circuit 30 and circuit 30t and calculates the specified alternator voltage required to provide the requested energy.
For vehicles up to production date April 2nd, 2018 or Model 463.342 the following applies: The SAM control unit reads in the calculated data of the battery sensor over the battery sensor LIN, it also measures the voltages at circuit 30 and circuit 30g and calculates the specified alternator voltage required to provide the requested energy.
Model 463.242
as of Model year 2013
The additional battery (G1/3) is installed in addition to the on-board electrical system battery. This makes it possible to start the engine when the on-board electrical system battery is discharged (emergency engine start). The additional battery is switched on during engine start at the same time as the on-board electrical system battery. It is thus possible to find out the charge level of the additional battery and to charge the additional battery, if necessary.
Charge on-board electrical system battery
Charging of the on-board electrical system battery requires that the specified voltage be determined. The specified voltage is the voltage that must be present at the terminals of the on-board electrical system battery in order to charge the on-board electrical system battery in an optimum manner. Depending on various factors, the specified voltage is determined using the alternator management or using the temperature-dependent charging characteristic. After the engine is started, quick charging is performed first at high voltage until the charge level of the on-board electrical system battery is recognized as being sufficient.
Rapid charging occurs with a charging voltage of 15V and can last from 20 s to 1 h.
Following this, a temperature-dependent characteristic or the alternator management function is used.
The alternator management system includes lowering the charging voltage to 12.8V and the possibility of regenerative braking when the engine is in deceleration mode. When the alternator management system is active, one of the front doors is opened and the vehicle speed is 0 km/h, the alternator management system switches into the jump start or workshop mode. At the same time, the alternator voltage is increased constantly to 14.3 V. This jump start or workshop mode is not canceled until the vehicle speed is higher than 0 km/h. An emergency shutoff is activated when driving down long hills in order to avoid overcharging of the on-board electrical system battery resulting from long periods of deceleration fuel shutoff. This emergency shutoff deactivates regenerative braking in cases of high voltage combined with low power consumption. If the on-board electrical system battery becomes fully charged (for example after driving in the cold or long downhill travel), the voltage is lowered further to return the battery to its optimum charge level of 80%.
Voltage provision
Quick charging:
- Voltage up to 15 V
- Once after terminal 50 ON
- Optimized charging of on-board electrical system battery, incl. during short trips
- Duration 20 s to 1 h
- Rapid charging ends when charge of on-board electrical system battery is ≥ 80 %
- No quick charging when towing a trailer
- No quick charging when the on-board electrical system battery is too warm
Temperature-based charging:
- Quick charging ended, alternator management not possible
- Voltage range 13.5 to 15 V
- Linear charging characteristic (temperature-dependent)
- Temperature of on-board electrical system battery < 10 °C
- Outside temperature< 0 °C
Transition to alternator management:
- Quick charging ended
- Stable engine operation
- Temperature of on-board electrical system battery > 10 °C
- Outside temperature> 0 °C
- Charge level of on-board electrical system battery > 70 %
- No trailer operation
Alternator management:
- Voltage 12.8 V, with some exterior lamp functions 13.5 V
- Charge level of on-board electrical system battery ≥ 80 %
- Reduced consumer power consumption
- With air conditioning ON and high blower setting 14.3 V
Transition to charging in deceleration mode:
- Stable engine operation
- CDI control unit or ME [ME-SFI] control unit detects deceleration mode
Charging in deceleration mode:
- Voltage up to 15 V
- Activated by CDI control unit or ME [ME-SFI] control unit
- On-board electrical system battery charged when "free" energy is available
Alternator regulation (alternator management)
Alternator regulation (alternator management):
- Takes place in the CDI control unit or ME-SFI [ME] control unit
- Sets the specified voltage of the energy management
- Switches to regenerative braking voltage in deceleration mode
- Sets a lower voltage in exceptional cases (e.g. stall prevention, cold start at high altitude, catalytic converter heating)
The alternator control actuates the alternator's power output. The CDI control unit or the ME-SFI control unit communicates with the alternator via the drive train LIN (LIN C1) and evaluates the alternator operating rate.
For vehicles as of 03 04 2018 except Model 463 342 the following applies:
The CDI control unit or the ME-SFI [ME] control unit sends information on alternator capacity over the drive train CAN, powertrain control unit, chassis FlexRay, electronic ignition lock control unit and the interior CAN to the front SAM control unit.
The state of the on-board electrical system battery is recorded by the battery sensor. The battery sensor sends corresponding parameters for the on-board electrical system battery over the battery sensor-LIN to the front SAM control unit. The front SAM control unit evaluates all of the relevant information and calculates the specified voltage required for the alternator. The front SAM control unit then sends this value to the CDI control unit or the ME-SFI control unit via interior CAN, electronic ignition lock control unit, chassis FlexRay, powertrain control unit and drive train CAN. The CDI control unit or the ME-SFI [ME] control unit evaluates this, taking additional input factors (e.g. A/C ON) into consideration, and calculates the ideal specified voltage for the alternator. The CDI control unit or the ME-SFI [ME] control unit then calculates the alternator specified voltage via drive train LIN to the alternator, which then sets it. In addition, the CDI control unit or ME-SFI [ME] control unit checks the input factors for plausibility in order to rule out any overcharging or faulty charging of the on-board electrical system battery.
The CDI control unit or the ME-SFI control unit compares the optimum specified voltage for the alternator with the actual alternator power and is thus able to determine the energy state of the on-board electrical system. The continuous comparison of these two values and the corresponding corrections are designated as power management. As soon as it becomes apparent that the on-board electrical system voltage is not high enough, the power management is gradually reduced. The alternator can then make its full output available.
The energy management in the CDI control unit or in the ME-SFI [ME] control unit adopts the alternator specified voltage values for the front SAM control unit as a guideline value only, because certain vehicle conditions, e.g. engine comfort, idle stability, engine start, irregular engine operation have to be taken into consideration. Therefore, the actual specified voltage of the alternator is obtained from the alternator specified voltages sent by the front SAM control unit, superimposed by power management corrections.
If a fault is found on the battery sensor, the energy management switches to a fixed voltage of 14.3 V. This behavior can also be activated using a diagnosis service in order to check the alternator, for example.
For vehicles up to production date April 2nd, 2018 or Model 463.342 the following applies:
The CDI control unit (engine 642) or the ME-SFI control unit (engine 157, 273) then sends information about the alternator operating rate via chassis CAN 1, the electronic ignition lock control unit and interior CAN to the SAM control unit.
On vehicles with engine 176, the ME-SFI control unit sends information about the alternator operating rate via the engine CAN (CAN C1), powertrain control unit, chassis CAN 1, electronic ignition lock control unit and interior CAN to the SAM control unit.
The state of the on-board electrical system battery is recorded by the battery sensor. It sends corresponding parameters via battery sensor LIN to the SAM control unit. The SAM control unit evaluates all of the relevant information and calculates the specified voltage required for the alternator.
The SAM control unit then sends this value via the interior CAN, electronic ignition lock control unit and chassis CAN 1 to the CDI control unit (engine 642) or to the ME-SFI control unit (engine 157, 273).
On vehicles with engine 176, the SAM control unit sends this value via the interior CAN, electronic ignition lock control unit, chassis CAN 1, powertrain control unit and engine CAN to the ME-SFI control unit.
The CDI control unit or the ME-SFI [ME] control unit evaluates this, taking additional input factors (e.g. A/C ON) into consideration, and calculates the ideal specified voltage for the alternator. The CDI control unit or the ME-SFI control unit then requests the calculated specified voltage via the drive train LIN at the alternator; the alternator then sets this voltage. In addition, the CDI control unit or ME-SFI control unit checks the input factors for plausibility in order to rule out any overcharging or faulty charging of the on-board electrical system battery.
The CDI control unit or the ME-SFI control unit compares the optimum specified voltage for the alternator with the actual alternator power and is thus able to determine the energy state of the on-board electrical system. The continuous comparison of these two values and the corresponding corrections are designated as power management. As soon as it becomes apparent that the on-board electrical system voltage is not high enough, the power management is gradually reduced. The alternator can then make its full output available.
The energy management in the CDI control unit or in the ME-SFI control unit adopts the alternator specified voltage values for the SAM control unit as a guideline values only, because certain driving conditions, e.g. engine comfort, idle stability, engine start, irregular engine operation have to be taken into consideration. The actual specified voltage of the alternator is therefore obtained by taking both the specified voltages sent by the SAM control and that of the energy management into account.
If a fault is found in the battery sensor, the energy management function switches to a fixed voltage of U = 14.3 V. This behavior can also be activated using a diagnosis service in order to check the alternator, for example.
Dynamic idle speed control
Dynamic idle speed control sets the engine's idle speed such that no current needs to be drawn from the on-board electrical system battery when the vehicle is idling. The idle speed is increased for a higher consumer load. The idle speed is increased as a preventive measure.
In other words, the system does not respond to a lack of electrical energy, but rather sets the required idle speed based on the present load.
The following factors are used for dynamic idle speed control computations:
- Alternator excitation current
- Alternator operating rate
- On-board electrical system battery voltage
- On-board electrical system battery current
- State of on-board electrical system battery
- Engine speed
- Consumer reduction shutoff stage
- Engine start
The CDI control unit or the ME-SFI control unit communicates with the alternator via the drive train LIN and evaluates the alternator operating rate.
For vehicles as of 03 04 2018 except Model 463 342 the following applies:
The CDI control unit or the ME-SFI [ME] control unit sends the "Engine running" signal and information on alternator capacity via drive train CAN, powertrain control unit, chassis FlexRay, electronic ignition lock control unit and the interior CAN to the front SAM control unit.
The state, voltage and current of the on-board electrical system battery are detected by the battery sensor. The battery sensor sends corresponding parameters for the on-board electrical system battery over the battery sensor-LIN to the front SAM control unit. The front SAM control unit evaluates all relevant information and computes the energy required. If the energy requirement cannot be covered by the alternator management, the idle speed is increased. The maximum possible excitation current is calculated from the current excitation current and the alternator utilization. The maximum possible excitation current is used to calculate the maximum possible alternator current at different idle speeds. The front SAM control unit sends corresponding requests over the interior CAN, electronic ignition lock control unit, chassis FlexRay, powertrain control unit and drive train CAN to the CDI control unit or the ME-SFI [ME] control unit, which then raises the idle speed accordingly.
The idle speed increase is reversed under the following circumstances:
- Engine off or alternator defective
- Simultaneous occurrence of the following conditions:
- Consumer reduction not active
- Consumer load no longer high
For vehicles up to 02 04 2018 or Model 463 342 the following applies:
The CDI control unit (engine 642) or the ME-SFI control unit (engine 157, 273) then sends information about the alternator operating rate via chassis CAN 1, the electronic ignition lock control unit and interior CAN to the SAM control unit.
On vehicles with engine 176, the ME-SFI control unit sends information about the alternator operating rate via the engine CAN, powertrain control unit, chassis CAN 1, electronic ignition lock control unit and interior CAN to the SAM control unit.
The state, voltage and current of the on-board electrical system battery are detected by the battery sensor. It sends corresponding parameters via battery sensor LIN to the SAM control unit. The SAM control unit evaluates all relevant information and computes the required alternator current. The maximum possible excitation current is calculated from the current excitation current and the alternator utilization. The maximum possible excitation current is used to calculate the maximum possible alternator current at different idle speeds.
The SAM control unit sends corresponding requests via the interior CAN, electronic ignition lock control unit and chassis CAN 1 to the CDI control unit (engine 642) or to the ME-SFI control unit (engine 157, 273).
On vehicles with engine 176, the SAM control unit sends corresponding requests via the interior CAN, electronic ignition lock control unit, chassis CAN 1, powertrain control unit and engine CAN to the ME-SFI control unit.
The CDI control unit or the ME-SFI control unit increases the idle speed accordingly.
The idle speed is reversed under the following circumstances:
- Engine off or alternator defective
- Simultaneous occurrence of the following conditions:
- Consumer reduction not active
- Consumer load no longer high
Consumer reduction (deactivation of comfort functions)
If the alternator can no longer provide the required electrical power, the load on the on-board electrical system is reduced by cutting back comfort functions. This serves to avoid any significantly negative charge balance for the on-board electrical system battery. This in turn retains the engine's starting capability. The comfort functions are reactivated when the required electrical power to stabilize the on-board electrical system voltage is available again.
The function for cutting back comfort functions is activated when the on-board electrical system voltage drops below U = 12.2 V. The first consumer's power consumption is reduced at t = 20 s following engine start. If the cutback conditions remain unchanged, the power consumption of one further consumer will be reduced every following second.
For vehicles as of 03 04 2018 except Model 463 342 the following applies:
The front left reversible emergency tensioning retractor (A76) and the front right reversible emergency tensioning retractor (A76/1) have very high starting and operating currents. The power consumption of some high power consumers is therefore reduced or the consumers shut off altogether as quickly as possible for approx. 2 s when the reversible emergency tensioning retractors are triggered in order to reduce the load on the on-board electrical system.
The front SAM control unit transmits the request to limit the power output of or switch off consumers via the interior CAN to the relevant control units, that are connected to the interior CAN, and via the interior CAN, electronic ignition lock control unit, suspension FlexRay, powertrain control unit and drive CAN to the CDI or ME-SFI control unit. Furthermore, it sends the request via the interior CAN, electronic ignition lock control unit and user interface CAN (CAN HMI) to the head unit (A26/17).
The "De-icing" shut-off sequence (≤ 10 min) is included in the following table. A switch is then made to the "Comfort" shut-off sequence.
| Sequence | Shutoff stage | Power-reduced or deactivated function | Responsible control unit |
|---|---|---|---|
| 1 | 1 | PTC heater booster (R22/3), 1st branch, heat boosting (engine 656) | Climate Control control unit (N22/1) |
| 2 | 2 | PTC heater booster (R22/3), 2nd branch, heat boosting (engine 656) | Climate Control control unit (N22/1) |
| 3 | 3 | PTC heater booster (R22/3), 3rd branch, heat boosting (engine 656) | Climate Control control unit (N22/1) |
| 4 | 4 | PTC heater booster (R22/3), 4th branch, heat boosting (engine 656) | Climate Control control unit (N22/1) |
| 5 | 5 | PTC heater booster (R22/3), 5th branch, heat boosting (engine 656) | Climate Control control unit (N22/1) |
| 6 | 6 | PTC heater booster (R22/3), 6th branch, heat boosting (engine 656) | Climate Control control unit (N22/1) |
| 7 | 7 | Seat heater stage 3 | Rear SAM control unit (N10/8) |
| 8 | 8 | Seat heater stage 2 | Rear SAM control unit (N10/8) |
| 9 | 10 | Blower in rear passenger compartment P = 50% | Climate Control control unit (N22/1) |
| 10 | 11 | Blower in front P = 50% | Climate Control control unit (N22/1) |
| 11 | 12 | Fan P = 50% | CDI control unit (N3/9) (diesel engine) or ME-SFI [ME] control unit (N3/10) (gasoline engine) |
| 12 | 13 | Trunk socket, cigarette lighter (with code F90 (Ashtray insert for cup holder with cigarette lighter)) | Front SAM control unit (N10/6) |
| 13 | 14 | Mirror heater | Left front door control unit (N69/1) and right front door control unit (N69/2) |
| 14 | 15 | Spray nozzle hose heater | Front SAM control unit (N10/6) |
| 15 | 17 | Rear window heater | Rear SAM control unit (N10/8) |
| 16 | 20 | Seat heater stage 1 | Rear SAM control unit (N10/8) |
| 17 | 20 | Seat ventilation (with code PA9 (Active Multicolour Seat Package)) | Rear SAM control unit (N10/8) |
The shutoff sequence "Comfort" is shown in the table below.
| Sequence | Shutoff stage | Power-reduced or deactivated function | Responsible control unit |
|---|---|---|---|
| 1 | 1 | PTC heater booster (R22/3), 1st branch, heat boosting (engine 656) | Climate Control control unit (N22/1) |
| 2 | 2 | PTC heater booster (R22/3), 2nd branch, heat boosting (engine 656) | Climate Control control unit (N22/1) |
| 3 | 3 | PTC heater booster (R22/3), 3rd branch, heat boosting (engine 656) | Climate Control control unit (N22/1) |
| 4 | 4 | PTC heater booster (R22/3), 4th branch, heat boosting (engine 656) | Climate Control control unit (N22/1) |
| 5 | 5 | PTC heater booster (R22/3), 5th branch, heat boosting (engine 656) | Climate Control control unit (N22/1) |
| 6 | 6 | PTC heater booster (R22/3), 6th branch, heat boosting (engine 656) | Climate Control control unit (N22/1) |
| 7 | 9 | Spray nozzle hose heater | Front SAM control unit (N10/6) |
| 8 | 10 | Mirror heater | Left front door control unit (N69/1) and right front door control unit (N69/2) |
| 9 | 11 | Seat heater stage 3 | Rear SAM control unit (N10/8) |
| 10 | 12 | Rear window heater | Rear SAM control unit (N10/8) |
| 11 | 14 | Seat heater stage 2 | Rear SAM control unit (N10/8) |
| 12 | 15 | Blower in rear passenger compartment P = 50% | Climate Control control unit (N22/1) |
| 13 | 16 | Blower in front P = 50% | Climate Control control unit (N22/1) |
| 14 | 17 | Fan P = 50% | CDI control unit (N3/9) (diesel engine) or ME-SFI [ME] control unit (N3/10) (gasoline engine) |
| 15 | 18 | Trunk socket, cigarette lighter (with code F90 (Ashtray insert for cup holder with cigarette lighter)) | Front SAM control unit (N10/6) |
| 16 | 20 | Seat heater stage 1 | Rear SAM control unit (N10/8) |
| 17 | 20 | Seat ventilation (with code PA9 (Active Multicontour Seat Package)) | Rear SAM control unit (N10/8) |
If the on-board electrical system voltage has been stabilized to a value above 13.5 V, or if the permissible discharge current has been undershot, then the power output limitation or deactivation of consumers occurs in reverse order with a waiting time of 1 s each time.
The on-board electrical system emergency mode represents a special case of consumer reduction. This is activated by the energy management in the front SAM control unit if the voltage of the on-board electrical system battery remains below a defined voltage threshold for a certain period of time. The energy management uses all options available through dynamic power management to enforce a positive charge balance.
If the on-board electrical system voltage drops below 10.6V for longer than 10 s, the front SAM control unit activates the on-board electrical system emergency mode function.
This causes the activation of the following engine on energy management functions:
- Idle speed increase
- Deactivation of alternator management
- Consumer reduction with shutoff of short-term consumers
Unlike reducing the number of consumers, limiting the power output of or switching off consumers occurs with a cycle time of 200 ms.
As soon as the on-board electrical system voltage has stabilized to a value of 11.8V for 10 s or a change in circuit status from circuit 15R to circuit 15C has occurred, the front SAM control unit ends the on-board electrical system emergency mode function. Consumer output limitation or deactivation is canceled.
For vehicles up to 02 04 2018 or Model 463 342 the following applies:
The SAM control unit sends the request for power output limitation or consumer shutoff over the interior CAN to the control units connected to the interior CAN and over the interior CAN, electronic ignition lock control unit and the suspension CAN 1 to the control units connected to suspension CAN 1.
When the on-board electrical system voltage has been stabilized to a value above U = 12.2 V, consumer reduction is revoked in the reverse order with a waiting time between each of t = 1s.
The on-board electrical system emergency mode represents a special case of consumer reduction. This is activated by the energy management in the SAM control unit if the voltage of the on-board electrical system battery remains below a defined voltage threshold for a certain period of time. The energy management uses all options available through dynamic power management to enforce a positive charge balance.
If the on-board electrical system voltage drops below U = 10.6V for t ≥ 10 s, the SAM control unit activates the on-board electrical system emergency mode function.
This causes the activation of the following engine on energy management functions:
The shutoff sequence is shown in the following table.
- Idle speed increase
- Deactivation of alternator management
- Consumer reduction with shutoff of short-term consumers Unlike consumer reduction, power output limitation or consumer shutoff is done with a cycle time of t = 200 ms. As soon as the onboard electrical system voltage has stabilized for t ≥ 10 s at a value of U = 11.8V or a change in circuit status from circuit 15R to circuit 15C has occurred, the SAM control unit ends the on-board electrical system emergency mode function. The switched off or power reduced consumers are switched on again. The electronic ignition lock control unit sends the circuit 15 status over the interior CAN to the SAM control unit.
| Sequence | Shutoff stage | Power-reduced or deactivated function | Responsible control unit | Maximum current in A |
|---|---|---|---|---|
| 1 | 7 | Seat heater stage 3 | Driver seat control unit (N32/1) Front passenger seat control unit (N32/2) | 13, 2 |
| 2 | 8 | Seat heater stage 2 | Driver seat control unit (N32/1) Front passenger seat control unit (N32/2) | 13, 2 |
| 3 | 10 | Mirror heater | Left front door control unit (N69/1) Right front door control unit (N69/2) | 3, 5 |
| 4 | 11 | Steering wheel heater (with code VL0 (Heated multifunction steering wheel)) | Steering column tube module control unit (N80) | 8, 0 |
| 5 | 12 | Rear window heater | A/C control and operating unit (N22/7) | 30, 0 |
| 6 | 14 | Blower P = 50 % | A/C control and operating unit (N22/7) | 16, 0 |
| 7 | 15 | Fan P = 50% | A/C control and operating unit (N22/7) | 31, 0 |
| 8 | 18 | Seat heater stage 1 | Driver seat control unit (N32/1) Front passenger seat control unit (N32/2) | 3, 3 |
Power supply through additional battery (up to production date April 2nd, 2018 or Model 463.342, except code MJ7 (ECO start/stop function))
To be able to engage the park position "P" even with a discharged onboard electrical system battery, the electronic ignition lock control unit is additionally supplied with power via the additional battery. The capacity of the additional battery is 1.2 Ah.
The power supply function over the additional battery encompasses the following sub-functions:
- Determine state of additional battery
- Charge additional battery
Determine state of additional battery
The SAM control unit runs a battery state recognition immediately after the engine is started. This provides information on the availability of the additional battery's electrical output. If the engine is switched off during + the battery state recognition, the SAM control unit switches this off and I discards the previous results. In addition to the battery state recognition, the voltage of the additional battery is also constantly checked. To perform this check, charging must be stopped for t = 20 ms. The check is performed every t = 5 s.
After the engine has been started, the CDI control unit (engine 642) or the ME-SFI control unit (engine 157, 273) sends the "engine running" signal via chassis CAN 1, electronic ignition lock control unit and interior CAN to the SAM control unit.
On vehicles with engine 176, the ME-SFI control unit sends the "engine running" signal via the drive train CAN, powertrain control unit, chassis CAN 1, electronic ignition lock control unit and interior CAN to the SAM control unit.
The battery state recognition can be started using a diagnosis tester.
If voltage is not applied to the additional battery or if the additional battery is discharged or defective, the fault message "Backup battery fault" is shown in the multifunction display (A1p13) of the instrument cluster (A1). The request for this is sent by the SAM control unit over the interior CAN (except code E11 (Stealth lights with convoy marking)) or over the interior CAN, stealth lights control unit (N1) and the instrument cluster CAN (CAN KI) (with code E11 (Stealth lights with convoy marking)) to the instrument cluster.
Charge additional battery
The additional battery is charged as required after battery state recognition when the engine is running. The SAM control unit regulates the charging process of the additional battery.
The CDI control unit (engine 642) or the ME-SFI control unit (engine 157, 273) sends the "engine running" signal via chassis CAN 1, electronic ignition lock control unit and interior CAN to the SAM control unit.
On vehicles with engine 176, the ME-SFI control unit sends the "engine running" signal via the drive train CAN, powertrain control unit, chassis CAN 1, electronic ignition lock control unit and interior CAN to the SAM control unit.
| Electrical function schematic for alternator management | Model 463 (except 463.342) as of Model year 2019 | PE54.10-P-2064-97ZGB | |
| Model 463 (except 463.342) as of Model year 2013 up to Model year 2019 Model 463.342 as of Model year 2013 |
PE54.10-P-2064-97ZGA | ||
| Electrical function schematic for dynamic idle speed increase | Model 463 (except 463.342) as of Model year 2019 | PE54.10-P-2063-97ZGB | |
| Model 463 (except 463.342) as of Model year 2013 up to Model year 2019 Model 463.342 as of Model year 2013 |
PE54.10-P-2063-97ZGA | ||
| Electrical function schematic for comfort function shutoff | Model 463 (except 463.342) as of Model year 2019 | PE54.10-P-2076-97ZGB | |
| Model 463 (except 463.342) as of Model year 2013 up to Model year 2019 Model 463.342 as of Model year 2013 |
PE54.10-P-2076-97ZGA | ||
| Overview of energy management system components | GF54.10-P-9990GW |