61 20 908 Performing Battery "Power Reset" (For Programming/Coding Control Unit(S))

WARNING: This page is about a different car, the 2008 BMW Alpina and 2007 BMW Alpina. However, it is still accessible from the selected car via links, so may be relevant.

IMPORTANT: Observe safety instructions for handling vehicle battery . See 61 00 ... SAFETY INSTRUCTIONS FOR HANDLING VEHICLE BATTERY .

The following steps must be carried out for a "power reset":

Switch off and disconnect battery charger
Switch off ignition
Cars with ignition key: Turn ignition key to 0 position

Cars with identification sensor: Remove identification sensor from slot

Cars with comfort access system: Make sure terminal is in 0 position
Disconnect battery negative terminal
Reconnect battery negative terminal (to ensure bus activity)
Waiting time (5-10 seconds)
Disconnect battery negative terminal
Waiting time (1 minute)
Connect battery negative terminal and tighten.

Tightening torque . See GENERAL ELECTRICAL SYSTEM - TIGHTENING TORQUES -- ALPINA .

Connect and switch on battery charger
Switch ignition on