Information On Replacing ABS/ESP(R) Control Unit - AH42.45-Z-0820-01KOA

Model 447, 448, 636, 639 

Model 900, 901, 902, 903, 904, 905, 906, 909 

Always observe the following information when removing and installing control units to avoid any damage: 

• Before dismantling the control unit, the working area on the hydraulic unit has to be cleaned, to avoid any malfunctions caused by contamination.
• The control unit may only be touched on the outer edges.
• To prevent any fogging inside the control unit and the hydraulic unit, an appropriate waiting time must be adhered to prior to disassembly (e.g. for vehicles wet with rain). Only dry components may be installed in heated premises.
• The control unit and the hydraulic unit may not be blown on with compressed air. The seal on the control unit must not be removed.
• The control unit and the hydraulic unit may not be blown on with compressed air. The seal on the control unit must not be removed.
• The control unit must be carefully removed from and installed onto the hydraulic unit, in a straight line to avoid damaging the internal components.
• The sealing surface of the hydraulic unit must be free of oil, grease, dust and silicon before assembly.

  Do not use any sharp-edged or pointed tools for cleaning. Soiling must be removed using a cloth and, if necessary, plastic tools. The use of chemical cleaners is not permitted.

• If the sealing surface on the hydraulic unit exhibits score marks, scratches, cracks or recesses, the hydraulic unit has to be replaced. The sealing surface must not be processed.
• New screws only may be used for fastening, to avoid any damage through incorrect tightening torque caused by aluminum abrasion.
• Because of the deterioration in the screw-in thread each time a control unit is replaced, a change may only be made 5-times.
• If the screw-in thread is damaged, the hydraulic unit must be replaced.

  Screw-in threads must not be processed.

Only replace the control unit if the faulty is clearly in the control unit. This is then the case if the control unit has been mechanically damaged or if the diagnosis revealed a fault in the control unit or relay.