BST Activation

WARNING: This page does not describe the selected car, but rather 151 other vehicles, including the 2006 BMW X5, 2006 BMW M3, 2006 BMW 330Ci, 2006 BMW 325Ci, and 2005 BMW X5. However, it is still accessible from the selected car via links, so may be relevant.

Once activated, the ignitor generates a gas charge which is directed down the internal discharge tube

Fig 1: Identifying BST Activation (1 Of 3)

Courtesy of BMW OF NORTH AMERICA, INC.

This causes the tapered end of the B+ cable contact to dislodge from its seated position and immediately open the circuit.

Fig 2: Identifying BST Activation (2 Of 3)

Courtesy of BMW OF NORTH AMERICA, INC.

The force of the charge continues to push the cable contact away from its seated contact. The spring tabs of the housing are compresses as the contact pushes to the end of its travel.

Fig 3: Identifying BST Activation (3 Of 3)

Courtesy of BMW OF NORTH AMERICA, INC.

When the contact hits the end stop of the housing, it bounces back against the return spring which prevent it from closing the contact with the battery.