61 20 908 Performing Battery "Power Reset" (For Programming/Coding Control Unit(s))
WARNING: This page is about a different car, the 2007 BMW 550i and 2006 BMW 550i. However, it is still accessible from the selected car via links, so may be relevant.
IMPORTANT:
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: 61 21 1AZ . See BATTERY WITH TERMINAL for specs.
- Connect and switch on battery charger
- Switch ignition on