34 52 700 Replacing the DSC hydraulic control unit

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2013 BMW 128i, 2012 BMW 128i, 2011 BMW 128i, 2010 BMW 128i, and 2009 BMW 128i. However, it is still accessible from the selected car via links, so may be relevant.

Important! Read and comply with notes on ESD PROTECTION (ELECTRO STATIC DISCHARGE) (E82) or ESD PROTECTION (ELECTRO STATIC DISCHARGE) (E82)

Necessary preliminary tasks: Remove hydraulic unit. Immediately close off all hydraulic connections with protective caps! Clean the DSC control unit on the outside.

Important! The hydraulic unit must not be more than 7 years old. May only be replaced once. Check repair history! No longer install hydraulic unit if subjected to mechanical stress (dropped, impact). Then use lint-free cloths and cleaning agent free of mineral oil. Do not touch any contact surfaces on the connector, pressure sensor and control unit with the hand or objects.

Important! Control unit (2) must not come into contact with dirt or moisture. Contacts must not be bent!

Release screws (1). Firmly hold pump motor (3) together with valve block (4). Carefully detach DSC control unit (2).

Fig 1: Detaching Control Unit And Screws

Courtesy of BMW OF NORTH AMERICA, INC.

Important! The white moulding compound at the base of the DSC control unit (2) serves as a seal and must not be removed. Do not touch the contacts of pressure sensors (A) and (B) at DSC hydraulic control unit (1) and DSC control unit (2); otherwise, they could corrode.

Fig 2: Identifying Pressure Sensors, Valve Block And Control Unit

Courtesy of BMW OF NORTH AMERICA, INC.

Take DSC hydraulic control unit (2) out of the original packaging (part number 67 97 896). Place the DSC hydraulic unit (2) straight on control unit (1) without twisting. Installation note: Replace screws (3). Tightening torque 34 51 1AZ

Fig 3: Installing Hydraulic Unit, Retaining Tab And Screw Plug

Courtesy of BMW OF NORTH AMERICA, INC.

Important! The hydraulic unit is completely sealed in the area of the pressure sensor connection only after complete assembly.

Installation note: When installing the hydraulic unit, only remove retaining tab (4) and screw plug (5) directly before connecting the brake lines.

Brake line mix-up test: Bleed braking system