Electronic control unit
1. Disconnect the negative battery cable.
Note: Disconnecting the battery will erase all fault codes from the ECU memory. It is recommended that you check for codes using special diagnostic equipment before disconnecting the battery. Have this work done by a dealer or a specialist who has such equipment.
2. In the left corner of the engine compartment, unscrew the four screws and remove the cover of the electrical installation block (Fig. 12.2).
3. Disconnect the connector plugs from the ECU and pull it out of the electrical assembly unit (fig. 12.3,a,b).
4. Installation is carried out in reverse order.
Note: If the ECU has been replaced, it must be coded using special equipment. Have this work done by a BMW dealer or a specialist who has such equipment. After connecting the battery, drive the car for several kilometers so that the ECU "learns" all the initial settings. If the engine still runs intermittently, the dealer or specialist can change the initial settings.
Fuel rail and injectors
Warning: Before you begin this work, read the warnings in paragraph 1.
5. Relieve pressure in the fuel system (see paragraph 8), then disconnect the negative battery cable.
Engine M43TU
Note: During installation, the injector sealing rings must be replaced.
6. Remove the upper section of the intake manifold as described in paragraph 13.
7. On the fuel rail, loosen the clamp and disconnect the fuel return hose, then unscrew the fitting nut and disconnect the fuel pressure line (fig. 12.7,a,b). Be prepared for fuel to leak from the holes and take precautions. Plug the holes in the rail and in the pipes to prevent dirt from creeping into the system.
8. Disconnect the vacuum hose from the pressure regulator 8 rail.
9. Disconnect the electrical wiring from the injectors and remove the injector wiring harness by releasing it from the fasteners.
10. Remove the two bolts that secure the ramp to the exhaust manifold (fig. 12.10).
11. Carefully lift the rail up so that the injectors come out of the manifold, then remove the rail together with the injectors from the engine.
12. To separate the injectors from the fuel rail, follow these steps:.
- a) Use a screwdriver to remove the metal retainer of the injector (fig. 12.12).
- b) Remove the injector from the fuel rail.
13. Before installing the injectors, replace all sealing rings, regardless of their condition (fig. 12.13).
14. Make sure that plastic washers are installed under the lower injector sealing rings.
15. Lubricate the O-rings with a small amount of petroleum jelly or 90 SAE gear oil.
16. Insert the injectors into the fuel rail and secure them with clamps. The injectors should be inserted so that after installing the rail in place, their electrical connectors are on top.
17. Install the ramp with injectors in place, making sure that the injectors enter their holes in the manifold.
18. The rest of the installation is carried out in the reverse order of removal. Install the upper section of the intake manifold as described in paragraph 13. Fill the system with fuel (insert the fuel pump fuse and turn on the ignition). Before starting the engine, check for fuel leaks.
Engine N42
19. Remove the two nuts, lift the front edge of the plastic cover above the engine and pull it forward.
20. At the rear of the engine compartment, remove the cabin filter cover by turning its latches 90° counterclockwise. Pull the filter out of the housing.
21. Unfasten the fasteners and remove the wires from the box (fig. 12.21).
22. Remove the four screws and pull the cabin filter housing forward (fig. 12.22).
23. In the left rear corner of the engine compartment, pull off the seal, turn the two fasteners and move the trim panel forward a little (fig. 12.23).
24. Remove the two screws and the heater inlet duct (fig. 12.24).
25. Press the retaining sleeve inward and disconnect the fuel supply line from the fuel rail. Be prepared for fuel to leak from the holes and take appropriate precautions. Plug the holes with plugs to prevent dirt from entering the system (fig. 12.25).
26. Unhook the cable, unscrew the two nuts securing the bracket to the cylinder head, then unscrew the two bolts securing the fuel rail and remove the rail together with the injectors (fig. 12.26).
27. Disconnect the electrical wiring from the injectors. If necessary, cut the clamps securing the wiring harness and free the fuel rail from them (fig. 12.27).
28. Remove the clips and pull the injectors out of the rail (fig. 12.28).
29. Lubricate the injector sealing rings with a small amount of petroleum jelly or acid-free grease.
30. Insert the injectors into the fuel rail and secure them with clamps.
31. The rest of the installation is carried out in the reverse order of removal.
Engine M52TU
32. Perform the actions specified in paragraphs 20-24.
33. Remove the plugs, unscrew the screws and remove the cover over the injectors (see fig. 12.44).
34. Disconnect the vacuum hose from the fuel pressure regulator.
35. Disconnect the electrical connector of the air inlet temperature sensor and remove the box with wires from the injectors.
36. Mark the two oxygen sensor connectors so as not to mix them up during installation, disconnect the connectors and release them from the clips.
37. Mark the pressure and return pipes and disconnect them from the ramp.
38. Remove the four screws and remove the fuel rail together with the injectors (see fig. 12.48).
39. To separate the injectors from the fuel rail, follow these steps:.
- a) Remove the injector retainers with a screwdriver.
- b) Remove the injectors from the ramp.
40. Lubricate the injector sealing rings with a small amount of petroleum jelly or acid-free grease.
41. Insert the injectors into the fuel rail and secure them with clamps.
42. The rest of the installation is carried out in the reverse order of removal.
Engine M54
43. Perform the actions specified in paragraphs 20-24.
44. Remove the plugs, unscrew the screws and remove the cover over the injectors (fig. 12.44).
45. Mark the two oxygen sensor connectors so as not to mix them up during installation, disconnect the connectors and release them from the clips.
46. Disconnect the electrical connector of the air inlet temperature sensor, the connector of the solenoid of the valve timing regulator VAN0S and remove the box with wires from the injectors (fig. 12.46,a-c).
47. Disconnect the fuel supply hose from the ramp (fig. 12.47).
48. Remove the four screws and remove the fuel rail together with the injectors (fig. 12.48).
49. To separate the injectors from the fuel rail, follow these steps:.
- a) Remove the injector retainers with a screwdriver.
- b) Remove the injectors from the ramp.
50. Lubricate the injector sealing rings with a small amount of petroleum jelly or acid-free grease.
51. Insert the injectors into the fuel rail and secure them with clamps.
52. The rest of the installation is carried out in the reverse order of removal.
Fuel pressure regulator
Warning: Before you begin this work, read the warning in paragraph 1.
53. Relieve pressure in the fuel system (see paragraph 8), then disconnect the negative battery cable.
Engine M43TU
Note: New o-rings will be required for installation.
54. Disconnect the vacuum hose from the regulator (fig. 12.54).
55. To improve access, disconnect the crankcase ventilation hose from the cylinder head cover.
56. Remember the position of the vacuum hose connection on the regulator so that you can install it in the same position later.
57. To provide sufficient space for removing the regulator, remove the lifting eye from the cylinder head.
58. On models where the regulator is secured with a bracket and a nut, unscrew the nut and remove the bracket.
59. On models where the regulator is secured with a clip, remove the clip.
60. Turn the regulator and pull it out of the ramp. The regulator is difficult to pull out of the ramp because of the sealing rings.
61. Before installing the regulator in the ramp, check the condition of the sealing rings and replace them if necessary (fig. 12.61).
62. The regulator is installed in the reverse order.
Engine N42
63. On this engine the pressure regulator is built into the fuel filter.
64. If the regulator is faulty, replace the filter assembly.
Engine M52TU
65. To expand the working space, remove the HVAC air inlet duct from the rear of the engine compartment as follows.
- a) Turn the three cabin filter cover fasteners 90° counterclockwise and remove the cover. Pull out the filter.
- b) Unfasten the fasteners of the box for laying the wires and remove the wiring from the box (see fig. 12.21)
- c) Unscrew the four screws securing the cabin filter housing and pull out the housing.
- d) Remove the two screws and pull the air duct upwards (see fig. 12.24).
66. Remove the cover from the fuel rail by pulling out the plugs and unscrewing the two screws that secure it.
67. Disconnect the vacuum hose from the fuel pressure regulator (fig. 12.67).
68. Remove the spring clip and pull the regulator out of the fuel rail while rotating it.
69. Before installation, inspect the sealing rings and replace if necessary.
70. The regulator is installed in the reverse order, taking into account the following notes.
- a) Make sure that the regulator is inserted all the way and is securely held in the fuel rail.
- 6) Securely fasten the regulator with the spring clip.
- c) Finally, fill the fuel system (insert the fuel pump fuse and turn on the ignition. Check the affected areas for leaks.
Engine M54
71. On these engines, the pressure regulator is structurally combined with the fuel filter. If the regulator is faulty, the filter assembly must be replaced.
Air flow sensor
Engine M43TU
Note: The sensor seal may need to be replaced during assembly.
72. Disconnect the negative battery cable.
73. Disconnect the air flow sensor electrical connector (fig. 12.73).
74. Loosen the clamp and disconnect the air duct from the flow sensor.
75. Release the sensor from the clips and remove the air flow sensor.
76. Install the sensor in the reverse order. Inspect the gasket and replace it if damaged.
Engine N42
77. Disconnect the negative battery cable.
78. Loosen the clamp and disconnect the air inlet duct and resonance chamber from the air cleaner.
79. Unscrew the two nuts and remove the air flow sensor from the air cleaner.
80. Installation is carried out in reverse order.
Engine M52TU
Note: The sensor seal may need to be replaced during assembly.
81. Turn off the ignition. Disconnect the electrical connector from the sensor (see fig. 12.84).
82. Disconnect the vacuum hose from the intake air duct, remove the sensor together with the intake air duct.
83. Installation is carried out in the reverse order. Check the condition of the seal and, if necessary, replace.
Engine M54
Note: The sensor seal may need to be replaced during assembly.
84. Turn off the ignition. Disconnect the electrical connector from the sensor (Fig. 12.84).
85. Loosen the clamp and disconnect the air inlet duct from the sensor. Remove the sensor from the air cleaner.
86. Installation is carried out in the reverse order. Check the condition of the seal and, if necessary, replace.
Throttle position sensor
Engine M43TU
Note: The O-ring may need to be replaced during assembly.
87. Turn off the ignition.
88. Disconnect the electrical connector from the sensor (Fig. 12.88).
89. Remove the two screws securing the sensor and remove it from the throttle body.
90. Installation is performed in the reverse order. Check the condition of the sealing ring and replace it if necessary. Sensor adjustment is not necessary.
Engine N42
91. On this engine, the throttle valve has an electric drive based on a signal from the accelerator pedal position sensor. The electric actuator for turning the throttle valve is made integral with the valve body. Removal of the throttle body is described in paragraph 11. The accelerator pedal position sensor is made integral with the pedal. Removal of the pedal is described in paragraph 8.
Engines M52TU and M54
92. The throttle position sensor is made integral with the throttle body. Removal of the throttle body is described in paragraph 11.
93. Installation is performed in the reverse order of removal. Please note: if a new valve body with a position sensor is installed, all parameter values adapted to the old body must be deleted from the ECU memory. This work can be performed by a BMW dealer or specialists from a branded service station. After deleting the old information, the ECU will determine and remember the new parameters during vehicle operation.
Coolant temperature sensor
Engine M43TU
94. The sensor is located on the left side of the cylinder head. Partially drain the coolant and remove the upper section of the intake manifold (see paragraph 13).
95. Unscrew the sensor from the cylinder head.
96. Installation is performed in the reverse order. Tighten the sensor to the required torque. Fill the cooling system.
Engine N42
97. The sensor is located on the left side of the cylinder block. Partially drain the coolant.
98. Remove the generator as described in Chapter 5A.
99. Disconnect the wiring from the sensor and unscrew the sensor from the cylinder block (fig. 12.99).
100. Installation is performed in the reverse order. Tighten the sensor to the required torque. Fill the cooling system.
Engines M52TU and M54
101. The sensor is located on the left side of the cylinder head, under the intake manifold. Partially drain the coolant and remove the intake manifold (see paragraph 13).
102. Disconnect the wiring from the sensor and unscrew the sensor from the cylinder block.
103. Installation is performed in the reverse order. Tighten the sensor to the required torque. Fill the cooling system.
Crankshaft position sensor
Engine M43TU
104. Raise the front of the vehicle and place it on reliable supports. Remove the engine crankcase guard.
105. The sensor is located under the starter. Disconnect the electrical connector from the sensor, unscrew the sensor mounting screw and remove the sensor.
106. Installation is carried out in the reverse order. Check the condition of the seal and replace it if necessary.
Engine N42
107. The sensor is located under the starter. Remove the intake manifold as described in paragraph 13.
108. Disconnect the electrical connector from the sensor, unscrew the sensor mounting screw and remove the sensor (fig. 12.108).
109. Check the condition of the sealing ring and replace it if necessary. Install the sensor in place and tighten the screw that secures it to the required torque.
110. Otherwise, installation is carried out in the reverse order of removal.
Engine M52TU
111. Perform the actions specified in paragraphs 104-105.
Engine M54
112. Raise the front of the vehicle and place it on reliable supports. Remove the engine crankcase guard.
113. Remove the amplifier between the lower suspension arms. Keep in mind that when installing the amplifier, its mounting bolts must be replaced.
114. The sensor is located under the starter. Disconnect the electrical connector from the sensor, unscrew the sensor mounting screw and remove the sensor.
115. Installation is performed in the reverse order of removal. When installing the amplifier, replace the bolts with new ones.
Camshaft Position Sensor
Engine M43TU
116. The sensor is located on the upper cover of the camshaft drive chain.
117. Turn off the ignition and disconnect the sensor electrical connector.
118. To facilitate access to the sensor, unscrew the bolts securing the secondary air injection solenoid valve and bracket and move them to the side (fig. 12.118).
119. Unscrew the sensor mounting bolt and remove it from the engine (fig. 12.119).
120. Check the condition of the sealing ring and replace if necessary.
121. Install the sensor in place and secure it securely with the bolt.
122. Otherwise, installation is carried out in the reverse order of removal.
Engine N42
123. The sensors are located on the front side of the cylinder head under the ends of the corresponding camshafts. Turn off the ignition.
124. Remove the two fasteners and remove the cover from the front cross panel of the engine compartment.
125. Disconnect the sensor electrical connector (squeeze the tabs of the clamps) (fig. 12.125).
126. Unscrew the sensor mounting bolt and remove the sensor from the engine.
127. The sensor is installed in the reverse order. Check the condition of the seal and replace it if necessary.
Intake camshaft (engines M52TU and M54)
128. Turn off the ignition. Remove the air cleaner (see paragraph 2).
129. To access the sensor, disconnect the electrical connector from the VANOS valve timing control solenoid and unscrew the valve (fig. 12.129).
130. Trace the sensor wires and disconnect the electrical connector where it attaches to the electrical box behind the generator.
131. Loosen the sensor mounting screw and remove the sensor from the cylinder head (fig. 12.131).
Exhaust camshaft (engines M52TU and M54)
132. Turn off the ignition.
133. Disconnect the electrical connector of the sensor, unscrew the mounting screw and remove the sensor (fig. 12.133).
134. Installation is performed in the reverse order of removal. Check the condition of the seal and replace it if necessary.
Oxygen sensor
135. See Chapter 46.
Idle control valve
Engine M43TU
136. The valve is located outside the throttle body (fig. 12.136).
137. Turn off the ignition.
138. Disconnect the valve electrical connector.
139. Disconnect the vacuum hose from the valve.
140. Remove the two valve mounting screws and remove it from the valve body
141. Installation is performed in the reverse order. Clean the valve mounting surface. Check the condition of the seal and, if necessary, replace it.
Engine N42
142. On this engine, idle speed is controlled by the lift and duration of opening of the intake valves, controlled by the electronic engine control unit
Engines M52TU and M54
143. Disconnect the negative battery cable.
144. The idle air control valve on these engines is located under the intake manifold and above the throttle body.
145. Remove the air cleaner (see paragraph 2).
146. Remove the accelerator cable housing from the bracket on the throttle body.
147. Release the clamps and disconnect the air duct from the throttle body and from the idle air valve.
148. Disconnect the electrical connectors of the idle air control valve and the intake manifold flap control valve.
149. Remove the cable bracket mounting nut and two idle air valve bracket mounting screws. Remove the valve from the intake manifold (fig. 12.149). The gasket between the valve and the manifold can be discarded - a new gasket is required for installation.
150. Lubricate the new gasket with grease and apply it to the intake manifold. Install the idle air control valve and tighten the support bracket fasteners securely.
151. Otherwise, installation is carried out in the reverse order of removal.
Fuel pump repe
152. Disconnect the negative battery cable.
153. Remove the glove box on the passenger side as described in paragraph 27 of Chapter 11.
154. Insert a flat-head screwdriver into the slot of the glove box light socket and press the socket outward. Disconnect the socket from the wiring once the electrical connector is exposed.
155. Remove the five screws, remove the retainer and remove the drawer frame from the front panel (if necessary, see Chapter 11 for more information).
156. Disconnect the electrical connectors from the main control module (fig. 12.156).
157. Remove the fuel pump relay from the relay board (fig. 12.157).
158. Install the relay in reverse order.
Main relay of the control system
159. Turn off the ignition.
160. In the left corner of the engine compartment, unscrew the four screws and remove the cover of the electrical assembly block (see fig. 12.2).
161. Remove the relay from the socket (fig. 12.161).
162. Installation is carried out in reverse order.
Accelerator Pedal Position Sensor
Engine N42
163 The pedal position sensor is structurally integrated with the pedal unit. Removal of the pedal is described in paragraph 6.
Intake Manifold Pressure Sensor
164. Turn off the ignition. Unscrew the two nuts, lift the front edge of the cover over the engine and pull it forward.
165. Disconnect the electrical connector plug from the sensor, unscrew the sensor mounting screws and remove it from the manifold (fig. 12.165).
166. The sensor is installed in the reverse order.