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

NOTE: Do not connect continuous trickle charger to the cigarette lighter.

The cigarette lighter is powered by the rear distribution box via a relay. This relay drops out after terminal 15 OFF. This means that a continuous trickle charger connected to the cigarette lighter is disconnected from the battery.

Charge the battery via the jump-start connection points. 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.
- Recode the Car Access System (CAS) when installing a battery with a different capacity.
Delete fault entries in the Digital Motor 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 is entered in the DME or DDE.