Vehicle Damage Warnings
Instructions for Disconnecting and Connecting BatteryNote: If the ignition is not turned off when the battery is disconnected, fault memories may set in some control units.
Caution!
- Disconnecting the battery may cancel the fault memories of some control units. Consequently, before disconnecting the car's battery, always interrogate the fault memories. Investigate stored faults and, once any faults have been remedied, cancel the fault memory.
- E31, E32, E34, E36 only:
The radio can only be put back into service after battery disconnection by keying the radio code back in. For this reason, obtain the radio code card from customer before starting work. Note down programmed stations and store these stations back in memory once the battery has been reconnected.
- Stored settings of the on-board computer and clock will also be lost.
Disconnect Battery:
- If, when the repairs in the repair instructions are being carried out, reference is made to disconnect the battery, this instruction must be followed in each case for reasons of safety.
- The battery and the leads to the alternator and starter motor must not be disconnected while the engine is running.
- Detach terminal of battery negative lead from car battery and second battery if fitted. Cover up negative terminal(s).
- If the battery is not disconnected when working on components, cable connections etc., faults can occur in the fault memories of the relevant control units.