Replacing the sensors of the engine management system (BMW 7 Series E38)

1. The procedure for replacing sensors consists of disconnecting the connector and unscrewing or removing the sensor.















2. The engine oil temperature and pressure sensors are located on the oil filter base.





3. The temperature sensor in the control electronics compartment is installed directly in the compartment. To access the sensor, remove the compartment cover. Disconnect the connector, release the clamps and remove the sensor.

Engine oil level sensor

1. Turn off the ignition and drain the engine oil.







2. Disconnect the sensor connector located on the engine crankcase.





3. Loosen the fasteners and remove the sensor. Use a new gasket when installing.

Coolant temperature sensor

1. On the engine M51 remove the intake manifold (see chapter Engine), disconnect the connector and remove the sensor.







2. On the engine M52 the sensor is located at the front, under the intake manifold. Remove the injector cover (see chapter Fuel and exhaust systems) and disconnect the crankcase ventilation line. Disconnect the connector and unscrew the sensor.





3. On the engine M52TU the sensor is located under the intake manifold, in the cylinder head, next to cylinder #6. Remove the intake manifold, disconnect the connector and unscrew the sensor.





4. On the engine M60 the sensor (1) is located on the rear side of the engine cooling system expansion tank. Disconnect the connector and remove the sensor.







5. On the engine M62 with IAC valve disconnect the connector and remove the sensor. When absence of IAC valve the coolant temperature sensor is installed in the front part of the pipeline – remove the vacuum pipes, disconnect the connector (2) and remove the sensor.





6. On the engine M67 remove the connector (1) and move the wiring harness (2) to the side. Unscrew the sensor using a special tool.

When installing, replace the sensor sealing ring if necessary.

Intake Air Temperature (IAT) Sensor

1. On the engine M52 remove the throttle body (see chapter Fuel and exhaust systems).

The drive cables and throttle body heater system remain connected. Disconnect the connector, press the retainer and remove the sensor.

2. On the engine M52TU remove the injector cover (see chapter Fuel and exhaust systems). Disconnect the connector, press the lock and remove the sensor.





3. On engines M60 and M62 remove the top engine cover. On the engine M60 the sensor is built into the suction pipe, - press the retaining spring, disconnect the connector and unscrew the sensor. On the engine M62 the IAT sensor is mounted on the top of the air cleaner housing.



4. On the engine M73 press the retaining spring, disconnect the connector, press the retainer and remove the sensor.

Mass Air Flow Sensor (MAF)

Engine M51

1. Remove the air cleaner housing (see chapter Fuel and exhaust systems).



2. Disconnect the connector.



3. Loosen the clamp (1) securing the hose to the turbocharger and disconnect the air supply hose to the MAF sensor.



4. Raise the MAF sensor with the air cleaner housing slightly so that the hose clamp (1) can be loosened. Remove the air cleaner housing together with the air flow meter.



5. Press the spring clips on the left and right and remove the heat shield (1). Unscrew the bolts (2).

When installing, check the condition of the MAF sensor O-ring and replace the O-ring if necessary.

Engine M52

1. Loosen the clamp (1), press the brackets (2), disconnect the connector (3) and remove the MAF sensor.

2. When installing, check the condition of the sealing gasket between the MAF sensor and the upper part of the air cleaner and replace it if necessary.

Engine M52TU

1. Disconnect the MAF sensor connector (1), disconnect the vacuum hose (2) from the suction hose. Loosen the hose clamp (3).

2. Release the clamps on the air cleaner housing and disconnect the intake hose with the MAF sensor.

3. When installing, check the condition of the sealing gasket between the MAF sensor and the upper part of the air cleaner and replace it if necessary. Do not install a MAF sensor with a damaged grille.

Engine M57

1. Remove the top engine cover and engine cooling fan shroud.



2. Loosen the bolts and disconnect the suction hose in the direction of the arrow.



3. Disconnect the connector (2) of the MAF sensor, unscrew the bolts (1) and remove the sensor.

Engines M60, M62, M73

1. Disconnect the MAF sensor connector (1), loosen the clamp (2) and disconnect the suction hose from the MAF sensor.



2. Open the clamps (1) and disconnect the MAF sensor from the upper section of the air cleaner.

3. When installing, check the condition of the sealing gasket between the MAF sensor and the upper part of the air cleaner and replace it if necessary.

Boost pressure sensor

1. On the engine M57 the boost pressure sensor is installed at the rear of the intake manifold – disconnect the connector (1), unscrew the bolt (2) and remove the sensor (3).



2. On the engine M67 remove the top engine cover, disconnect the boost pressure sensor connector, unscrew the bolt (to the left of the sensor) and remove the sensor.

3. When installing, check and replace the boost pressure sensor sealing ring if necessary.

Crankshaft Position Sensor (CKP)

Engine M51

1. The CKP sensor is located under the starter.



2. Move the radiator hose at the engine inlet to the side to see the mark (1) on the timing cover. Turn the crankshaft clockwise until the mark on the vibration damper (2) aligns with the mark (1) on the timing cover. Disconnect the CKP sensor connector by pressing the connector retaining clip.



3. Remove the bolt, remove the CKP sensor together with the holder and disconnect the sensor from the holder.



4. Fit tool No.13 6 040 to the holder, fit the holder to the cylinder block and slide it forward as far as it will go. This sets the required interval (A) between the centering pin on the flywheel and the CKP sensor. Secure the holder.



5. Now that the tool is positioned close to the flywheel reference signal centering pin (1), remove the tool from the holder.

Do not unscrew the holder on the cylinder block any further.

6. Install new cKP sensor into the holder and connect the wiring connector.

Engine M52

1. The CKP sensor is installed under the starter, - remove the air cleaner housing, unscrew the bolt and remove the sensor.



2. Disconnect the electrical wiring connector (2) under the intake manifold.

Engines M57, M60, M62, M73

1. On the engine M60 remove the top engine cover.







2. Disconnect the CKP sensor wiring connector.







3. Remove the bolt and CKP sensor.

4. On engines M62 and M73 when replacing the gearbox, flywheel or CKP sensor, note that if one or more adjusting washers are installed between the sensor and the gearbox housing, you need to measure the distance between the sensor and the rotor teeth. To do this, turn the crankshaft clockwise forward by the central bolt so that one rotor tooth can be seen completely through the hole of the removed CKP sensor exactly in the center of the hole. Measure the distance from the flange of the sensor seat to the rotor tooth and subtract the distance from the mating surface of the sensor to its end from the result obtained. The resulting value is the gap distance between the sensor and the rotor and should be 0.55±0.2 mm. If necessary, adjust the gap using washers installed under the sensor.

Engine M67

1. Remove the rear section of the crankcase protection, disconnect the negative cable from the battery.



2. Remove the bolts (1) and move the positive battery cable (2) to the side.



3. Disconnect the connector (1), unscrew the bolt (2) and remove the CKP sensor (3).

Camshaft Position (CMP) Sensor

Engine M52

1. Remove the protective cover of the injectors and disconnect the connector of the solenoid valve of the timing phase adjustment system (Vanos) on the mounting plate of the injectors.



2. Unscrew the Vanos solenoid valve.

When installing, check and replace the sealing gasket if necessary.

3. Disconnect the hydraulic drive line from the Vanos system activator.



4. Remove the CMP sensor mounting bolt and disconnect its wiring connector under the intake manifold (3).

Use a new screw when installing. Check and replace the sealing gasket if necessary.

Engines M57, M60, M62

1. Remove the engine top cover and disconnect the CMP sensor connector.





2. Unscrew the bolt and remove the sensor.

When installing, check and replace the sensor sealing ring if necessary.

Engine M73

1. Remove the left distributor cap with high-voltage wires (see section Replacing ignition distributor rotors).



2. Unscrew the bolt and remove the sensor.

When installing, check and replace the sensor sealing ring if necessary.

Knock sensor

Do not mix up the knock sensor wiring when connecting its connectors, as this may cause engine damage.

1. Remove the intake manifold.

2. On the engine M52 disconnect the connector (1).









3. Remove the bolts and knock sensors.

4. Before installing the sensors, clean their mating surfaces.