Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Control Module, Disconnecting And Connecting To Hydraulic Unit: Notes
Special tools and workshop equipment required
- ESD Work Surface :VAS 6613
ABS Control Module -J104- will be subsequently called control module.
ABS Hydraulic Unit -N55- will be subsequently called hydraulic unit.
Condition
- If the control module is faulty, then the control module must be separated from the hydraulic unit and only the control module replaced.
- If the hydraulic unit is faulty, the hydraulic unit and the control module must be replaced together.
- The seal on the control module must not be pulled out or raised up.
There is a risk of destroying the hydraulic unit by removing the return flow pump.
- Never separate the return flow pump from the hydraulic unit.
-- Remove the control module and hydraulic unit. Refer to CONTROL MODULE FOR ABSJ104/HYDRAULIC UNIT FOR ABSN55, REMOVING AND INSTALLING .
Risk of damaging electrical components.
The electrostatic charge can damage electrical components.
- Procedures at the electrical components must only be performed at an electro-static discharge work surface.
-- Place the hydraulic unit with the control module on the ESD Work Surface :VAS 6613 .
Control module with three bolts
-- Remove the bolts -1- through -3-.
Continuation for all vehicles
Control module with four bolts
-- Remove the bolts -1- through -4-.
Continuation for all vehicles
-- Remove the control module -1- evenly in the -direction of the arrows- from the hydraulic unit -2-.
-- Cover the hydraulic unit actuators -2- with a lint-free cloth.
Connecting is done in reverse order, at the same time note the following:
Condition
- If a thread is damaged in the hydraulic unit, the hydraulic unit must be replaced.
- If the hydraulic unit sealing surface is damaged (for example through grooves or scrapes) the hydraulic unit must be replaced with the control module.
- The seal on the control module must not be pulled out or raised up.
-- Clean the sealing surfaces between the hydraulic unit and control module with a lint-free cleaning cloth.
Risk of damaging due to incorrect assembly.
Leaks between the control module and hydraulic unit.
- The new control module may be installed only 3 times.
- Control modules that were in operation are replaced after removal.
-- Place the control module evenly on the hydraulic unit.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.