61 12... General information on intelligent battery sensor (IBS)

The 12 V charging socket is supplied with voltage by the rear 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 voltage supply be registered by the vehicle.

• Do not introduce any additional connections at the battery negative terminal.
• Do not modify the grounding cable. The grounding cable also serves
• 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.

• 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 change via Service Function (Progman or DIS).
• Delete fault entries in the Digital Engine Electronics (DME) associated with battery replacement.
• Always proceed in accordance with the repair instructions.

• 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.