Electric Parking Brake (EPB) Actuators

When the BSCM receives a request from the EPB switch or through the CAN data bus, and if there is no internal fault to prevent the EPB action, the BSCM will process this request immediately. If request is coming from the EPB switch, the BSCM will check current EPB state and decide what action to apply. The BSCM will change internal signals and the motors will start to move, during the motors' moving period (either applying or releasing), the BSCM will set the EPB state to a temporary state (applying/releasing) for about 1-2 seconds. Then the BSCM will change to a stable state, either Applied, Released or Unknown after this short time.

Significant pad wear between EPB applications can lead to excessive EPB closure times. As pad wear occurs, the distance that the nut must travel before the full clamp force is achieved increases. To reduce this occurrence, the EPB should be applied at the first opportunity after a specified distance has been driven since the last EPB application and then immediately released. This will adjust the EPB system for any pad wear, making certain that closure times do not become excessive.

The EPB actuators receive the following signals:

Hardwire Inputs

• Park brake driver for left actuator on caliper
• Park brake driver for right actuator on caliper