Deactivating the 48 V electrical system

Deactivate the 48 V electrical system by opening the hood.
The deactivation takes place automatically.

Courtesy of BMW OF NORTH AMERICA, INC.

Determining the 48 V electrical system is de-energized

NOTE: TECHNICAL INFORMATION
Zero voltage (48 V electrical system switched-off) is only displayed in PAD mode.

Check

Press the START-STOPPING button quickly 3 times without stepping on the brake pedal to establish the PAD mode.
Check that the instrument cluster (KOMBI) is de-energized in PAD mode.

Courtesy of BMW OF NORTH AMERICA, INC.

Desired state

The Check Control message "48 V electrical system switched off." Or "Electrical additional storage switched off." (1) is displayed.

Result

» Lack of voltage cannot be determined with the Check Control message "48 V electrical system switched off." Or "Electrical additional storage switched off." (1). Work start is not permitted.

Measure

Repeat the "deactivate 48 V electrical system" service function.
- Vehicle management > service function > voltage supply > deactivate 48 V electrical system
Only if the Check Control message "48-volt on-board network switched off." Or "Electrical additional storage switched off." (1) is displayed in the instrument cluster (KOMBI), the 12V battery may be disconnected.

Result

» Lack of voltage cannot be determined with the Check Control message "48 V electrical system switched off." Or "Electrical additional storage switched off." (1). Work start is not permitted.

Measure

48-V battery with fault code related to relay is stuck in closed position and de-energized

Result

» The Check Control message reports that 48 V electrical system is switched off.

Measure

Exit PAD mode by pressing the START-STOPPING button once without stepping on the brake pedal.
"Disconnect the negative battery cable of the 48-V battery" work can be started.

Precondition

Ignition is switched off.

WARNING: Deactivate the 12-V electrical system.
Risk of short circuits! Risk of fire!

Make sure that there is no battery charger connected to the jump start terminal in the engine compartment.
For vehicles with additional electrical systems (48 V electrical system, high-voltage vehicle electrical system), this absolutely must be deactivated before the vehicle battery is disconnected.

WARNING: Deactivate the 48-V electrical system.
Risk of short circuits! Risk of fire!

Make sure that there is no charger connected to the jump start terminal in the engine compartment.

NOTE: RISK OF DAMAGE
Damage to the 48-V battery
If a 48-V battery that is disconnected from the electrical system is activated, the battery electronics will be damaged.

Only ever activate the 48 V electrical system when the 48 V battery is fully connected up.

NOTE: TECHNICAL INFORMATION
Observe notes on the 48-V battery. See NOTES ON THE 48-V BATTERY .

Deactivate the 48 V electrical system by opening the hood.
Deactivation is automatic.

Courtesy of BMW OF NORTH AMERICA, INC.

Check

NOTE: TECHNICAL INFORMATION
Zero voltage (48 V electrical system switched-off) is only displayed in PAD mode.

Press the START-STOPPING button quickly 3 times without stepping on the brake pedal to establish the PAD mode.
Check the de-energized state in the instrument cluster (KOMBI) in the PAD mode.

Courtesy of BMW OF NORTH AMERICA, INC.

Desired state

The Check Control message "48 V electrical system." switched off (1) is displayed.

Result

» Absence of voltage cannot be specified with the Check Control message "48 V electrical system switched off." (1). Work start is not permitted.

Measure

Repeat the "deactivate 48 V electrical system" service function.
- Vehicle management > service function > voltage supply > deactivate 48 V electrical system

Only if the Check Control message "48 V electrical system switched off." (1) is displayed in the instrument cluster (KOMBI), the 12V battery may be disconnected.

Contact the technical support if the absence of voltage is not clearly given.

Result

» The Check Control message reports that 48 V electrical system is switched off.

Measure

Exit PAD mode by pressing the START-STOPPING button once without stepping on the brake pedal.
"Disconnect the negative battery cable of the 48-V battery" work can be started.

Unlock and disconnect the CAN bus plug connection (1) of the gear sensor.
Release the clip (2).

Courtesy of BMW OF NORTH AMERICA, INC.
Loosen nut (1).
Detach the negative battery cable (2) of the 48-V battery from the negative battery terminal, set to one side and secure.

Courtesy of BMW OF NORTH AMERICA, INC.
WARNING:
Unprotected battery terminals.
Risk of short circuits! Risk of fire!
- Cover the vehicle battery.
Cover the vehicle battery with the special tool 2 452 007 as shown.
Position the battery ground lead (1) as shown.

Courtesy of BMW OF NORTH AMERICA, INC.