The components of the anti-lock brake system (ABS) – removal and installation. BMW E46
Hydraulic unit
1 Removal and installation of the hydraulic unit in a garage is not possible, since it requires special diagnostic equipment and pumping systems required for BMW equipment. In this connection, we recommend you pass this specialized work service station.
Battery (models with ASC + 77 system
2 For the reasons set out in paragraph 1 of this section, we recommend that you entrust this work to those skilled service station.
an electronic control unit (ECU)
3 To remove this block, you must first remove the hydraulic unit, since the ECU is fixed to the wall of the hydraulic unit. In this connection, we recommend you this work by a qualified service station.
Sensors Front Wheel Removal
4 Place a block under the rear wheels and apply the parking brake. Lift the front of the vehicle and set it on supports (see. “By emi car installation on supports”). Remove a corresponding forward wheel. Locate the wiring harness connector (raspopozhen connector in a plastic protective casing). Remove the lid, remove the plug and disconnect it (Fig. 20.4).
5 Remove the bolt attaching the sensor to the steering knuckle and remove sensor with wiring from the vehicle (Fig. 20.5). Note. On some models, the sensors of the left and right wheels, respectively, has a label L and R. In addition, the right sensor has two green tags between the sensor and seal.
6 Before installing apply a little versatile sensor lubricant (grease, BMW recommends Staborax NBU 12 / k).
Fig. 20.4. Remove the cover and disconnect the connector of ABS wiring harness (shown by an arrow)
7 Make sure that the mating surfaces of the knuckle and the sensor cleaned, and then install. Make sure that the sensor is mounted on the right-side-vipnoy vehicle (where necessary, see. P. 5). Replace the bolt and tighten it to torque
8 Ensure that the sensor wiring is laid correctly and secured. Connect the electrical wiring. Place the connector into the housings secure the cover.
9 Establish a wheel, lower the car to the ground and tighten the wheel bolts to torque.
Sensors rear wheels:
10 Place a block under the front wheels. Lift the rear of the car and establish it on supports (see. “Lifting and installation of vehicle on supports”). Remove a corresponding back wheel.
11 Remove the sensor (see para. 4 and 5 percentage points).
12 Install sensor as described in paragraphs 6-9.
Rotors front wheel sensor
13 The rotors are fixed to the rear side of the hub. Inspect the rotors and check for damage and chipped teeth. If necessary to replace the rotor, disassemble the hub assembly with the replacement of the bearings (see chap. 10).
Fig. 21.7. Turn the clips (arrows) on the 90 ° counter-clockwise
ИзображениеFig. 20.5. Remove the bolt fastening of the gauge (arrow)

Rotors rear wheel sensor
14 The rotors  are fixed on the outer constant velocity joint. Inspect the rotors and check for damage and chipped teeth. If necessary to replace the rotor, replace the drive shaft assembly.