61 20 900 Disconnecting and connecting battery negative lead

WARNING: Observe SAFETY INFORMATIONS for handling vehicle battery.
Follow instructions for DISCONNECTING AND CONNECTING BATTERY .
Follow instructions on INTELLIGENT BATTERY SENSOR (IBS) .

Necessary preliminary work

IMPORTANT: Do not under any circumstances detach or lever off intelligent battery sensor (2) from battery by force.

Loosen nut (1). Tightening torque 61 21 1AZ .

Remove intelligent battery sensor (2) from battery and secure to side.

Fig 1: Identifying Intelligent Battery Sensor And Nut

Courtesy of BMW OF NORTH AMERICA, INC.