Exchanging Control Modules

Exchanging Control Modules






1 Pressure Sensor

• Do not touch the contacts.

• The illustration depends on the model.

2 Pressure Sensor

• The pressure sensor must be changed or damaged.

• The pressure sensor cannot be replaced.

• The illustration depends on the model.

3 Gasket

• The seal on the control module must not be pulled out or raised up.

• The seal on the control module cannot be replaced.

4 Valve Bodies

• The valve bodies must not be damaged or bent.

• Do not use any tools on the valve bodies.

5 Pump Motor Contact

• The contact must not be damaged or bent.

Replace the control module:

• If Vehicle Diagnosis, Testing and Information System (VAS 505 x) has determined that control module is faulty "Control Module Faulty".

• If there is visible damage to the control module housing or to the connector.

A control module that was removed may not be attached to a different hydraulic unit.

Replacing Control Modules

It is necessary to remove the ABS hydraulic unit (N55) and the ABS control module (J104). Refer to => [ ABS Hydraulic Unit with ABS Control Module ] ABS Hydraulic Unit With ABS Control Module.

The replacement should only be done by trained personnel.

Only the new parts in the repair kit may be used.

Only new screws may be used for attaching the control module to the hydraulic unit.

The seal on the control module must not be pulled out or raised up.

The seal on the control module cannot be replaced.

Cleaning the control module or hydraulic unit with compressed air is not permitted.

The valve coils inside the control module cannot be adjusted.

The valve coils inside the control module cannot be replaced.

The pressure sensor must be changed or damaged.

The pressure sensor cannot be replaced.

Do not place anything on the sensor housing.

It is not possible to perform any measurements on the contacts inside the control module.

It is not possible to perform any measurements on the contacts inside the hydraulic unit.

The valve bodies inside the hydraulic unit must not be damaged or bent.

The contacts cannot be replaced.

Do not use contact spray on the contacts and pressure sensor.

Make sure there are no foreign objects between the control module and the hydraulic unit.

Bleed the brake system after replacing the control module. Refer to => [ Brake System, Bleeding ] Service and Repair.

After replacing the control module and bleeding the brake system:

• Check and read the DTC memory with the (VAS 505 x).

• All brake lines must be connected correctly. Perform an output diagnostic test with the (VAS 505 x).

• All the ESP warning lamps must turn off.

Make sure the brakes are working correctly before driving the vehicle for the first time.