LEMON Manuals: Even more car manuals for everyone
Home >> BMW >> 2025 >> 230i >> Repair and Diagnosis >> External Pages >> Different car >> Section 67 (General Electrical System - Repair Instructions) >> Battery >> 12 00... Instructions for disconnecting and connecting battery >> Before disconnecting battery:

Before disconnecting battery:

WARNING: This page is about a different car, the 2002 BMW M Roadster, 2002 BMW M Coupe, 2001 BMW M Roadster, and 2001 BMW M Coupe. However, it is still accessible from the selected car via links, so may be relevant.

Switch off ignition.

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.
  • On vehicles with radio code: After disconnecting the battery, the radio code must be re-entered. Therefore obtain the radio code card from the customer beforehand. Note stored stations and restore them after connecting the battery.
  • Stored settings of the on-board computer and clock will also be lost.
  • All available central keys must be recoded for cars with first generation infrared transmitter locking systems.