Risk of injury caused by body parts being jammed or crushed. Risk of injury to skin and eyes caused by brake fluid spraying out at high pressure when working on the SBC brake system - AS42.46-Z-0001-01B

Prevent SBC self-test. 

Risk of injury 

The SBC brake system periodically carries out a self-test (the PreDriveCheck, PDC) during which high brake pressure is built up.

The automatic extension of the brake pistons during the test may result in serious bodily injury (jammed or crushed body parts). The brake pressure that is built up automatically may cause brake fluid to escape at high pressure, possibly resulting in serious injuries.

Safety precautions/instructions 

Disable the SBC self-test prior to performing any work in the wheel brake area.

Never perform any maintenance or repair work in the wheel brake area without first executing the SBC self-test disable routine.

After the SBC self-test has been disabled, work may only be performed in the wheel brake area (e.g. replacing brake pads and changing brake fluid). Prior to work on the hydraulic or operating unit, the SBC brake system must always  be deactivated using STAR DIAGNOSIS.

Even with the SBC self-test disabled, do not apply the brake pedal, as this will result in high pressure buildup and cause the brake cylinder to operate.

An SBC self-test sequence may be carried out whenever:

• The vehicle is opened by remote control,
• The driver, front passenger or rear door is opened,
• The trunk is opened,
• The key is turned to position a 1 in the ignition switch (EIS),
• The brake pedal is operated,
• The parking brake is released.