BMW 7 Series: Disconnecting And Connecting Negative Battery Cable

WARNING: Observe SAFETY INSTRUCTIONS for handling vehicle battery.

Follow instructions FOR DISCONNECTING AND CONNECTING BATTERY ! Observe notes on POWER SUPPLY /on intelligent battery sensor (IBS).

Necessary preliminary work

• Remove LUGGAGE COMPARTMENT FLOOR TRIM PANEL
  F07 only:
• Remove spare wheel well trim panel
  F11 only:
• Raise cargo area floor

Loosen nut (1).

Tightening torque 61 21 1AZ.

IMPORTANT: Do not under any circumstances use force to pull off negative terminal.

Detach battery earth lead with IBS towards top, lay to one side and secure.

Fig. 191: Identifying Battery Nut

GENERAL INFORMATION ON INTELLIGENT BATTERY SENSOR (IBS)

NOTE: Do not connect the charger to the 12 V charging socket.

The 12 V charging socket is supplied with voltage by the rear power distribution box via relay. This relay drops out after terminal 15 OFF. This means that a trickle charger connected at the 12 V charging socket will be disconnected from the battery. Only charge the battery via the jump start terminal point. Only then can the power supply be registered by the vehicle.

WARNING: Danger of destruction in event of mechanical strain

• Do not introduce any additional connections at the battery negative terminal.
• Do not modify the grounding cable. The grounding cable also serves to dissipate heat.
• Do not establish any connection between the IBS and the sensor screw.
• Do not use force when disconnecting the pole shoe from the battery terminal:
  • Do not pull on the grounding cable.
  • Do not place any tools under the IBS to lever off the pole shoe.
• Do not use IBS connections as levers.
• Use a torque wrench and set tightening torque in accordance with repair instructions.
• Do not release or tighten down sensor screw (screw with Torx head).
• Avoid contact between IBS and ground.

WARNING: Danger of destruction to IBS and cables when battery is replaced

• The IBS and the cables can be destroyed by mechanical strain when the battery is replaced. Therefore avoid mechanical strain.
• The size (capacity) of the battery required for the car is coded in the Car Access System (CAS).
• Use the battery size (capacity) installed as standard when replacing the battery.
• Register battery replacement via Service functions in diagnosis system.
• Delete fault entries in the Digital Engine Electronics (DME) associated with battery replacement.
• Always proceed in accordance with the repair instructions.

NOTE: Battery draining possible in spite of the intelligent battery sensor IBS being fault-free.

• A battery can be drained (e.g. with lights or radio switched on) even when the IBS functions perfectly in conjunction with power management.
• For this reason, only replace the IBS when a corresponding fault entry in the DME or DDE.

INSTRUCTIONS FOR DISCONNECTING AND CONNECTING BATTERY

Observe SAFETY INSTRUCTIONS FOR HANDLING VEHICLE BATTERY.

Before disconnecting battery:

Turn off the ignition and other electrical loads/consumers to prevent sparking when reconnecting.

NOTE: If the ignition is not turned off when the battery is disconnected, fault memories may be set in some control units.

IMPORTANT:

• There is a danger of mixing up battery leads: If the battery positive and negative leads are the same color and you are in doubt, follow the polarity to the battery, then mark and cover the leads.
• The on-board computer and clock may lose your data.

General notes on disconnecting battery

• Do not disconnect battery leads and leads from alternator and starter motor while engine is running.
• Cars with IBS on battery negative terminal:
  Do not under any circumstances pull/lever off pole shoes by force.

  Do not under any circumstances release socket-head cap screw of IBS.

• Disconnect terminal of BATTERY NEGATIVE LEAD from vehicle battery. Cover battery negative terminal(s) and secure.
• When work is carried out on the electrical system, faults may be caused in the fault memories of some control units when the battery is connected.
• When installing battery terminal: Tightening torque 61 21 1AZ.

After connecting battery

IMPORTANT: The scope of application of some systems may be restricted after a power supply interruption.

Likewise, individual settings may be lost.

Settings or activations must be carried out, depending on the equipment specification.

For example:

• If necessary, carry out ADJUSTMENT OF ACTIVE STEERING
• If necessary, activate SLIDE/TILT SUNROOF
• If necessary, activate power windows.

Refer to the diagnosis system for further vehicle-specific information.

NOTES/INFORMATION ON START ASSISTANCE (JUMP STARTING)

Do not start the engine with help of starting sprays.

Preparation

Conform with the following when starting the engine with a jump starting cable.

• Ensure that the jump starting cable wires are of appropriate cross-section size.
• Only use fuse-protected jump starting cables.
• Check whether the current-supplying battery has 12 V voltage.
• If the engine is started from the battery of another vehicle, ensure that there is no contact between the bodies of both vehicles.

IMPORTANT: Never touch electrically live ignition system components: high voltage - danger of injury!

If the battery in the vehicle supplying power is weak, start the engine of this vehicle and let it run at idling speed.

Operation

It is essential to conform to the procedures so as to avoid injury to persons or damage to parts.

• Automatic transmission: select drive position "P", apply parking brake.
• Manual transmission: move gear lever to neutral position, apply parking brake.
• Ensure that the jump leads cannot get caught in rotating parts, e.g. fan.
• First connect both positive poles of the batteries with one jump starting cable (red).
• Use the battery positive terminal in the engine compartment for vehicles with the battery in the luggage compartment.
• Then use the second jump starting cable (black) to connect the negative post of the current-supplying battery with the earth/ground point (not the negative pole or the body) of the vehicle to be started.

IMPORTANT: Do not connect the second jump starting cable (black) with the negative pole of the battery in the vehicle to be started. Produced gas could be ignited by sparks.

Risk of explosion!

After the engine of the vehicle to be started has fired, first disconnect the jump starting cable between the negative pole and the earth/ground point. Then remove the starting cable from the positive poles.

VEHICLE BATTERY - CLOSED-CIRCUIT CURRENT MONITORING

WARNING: Observe SAFETY INSTRUCTIONS for handling vehicle battery.

Necessary preliminary work

• Clamp off BATTERY NEGATIVE LEAD
• Disconnect Both negative battery cables

Connect adapter for closed-circuit current measurement..

Connect BMW diagnosis system.

Measure closed-circuit current.

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