Checking/replacing the pulse sensor (BMW 5 Series E39)

The DME control unit receives information about the crankshaft speed via a pulse sensor, which is located at the toothed wheel behind the crankshaft pulley. A second sensor, located at the front of the cylinder head, provides information about the completion of a full crankshaft revolution (cylinder identification).

Examination

Location of the plug connectors located under the intake manifold, viewed from the front:

• 1 - for knock sensor (closed);
• 2 - for the crankshaft pulse sensor;
• 3 - for cylinder identification sensor.

To check, disconnect the corresponding plug from the engine wiring harness. If necessary, first remove the intake manifold, as access to the plugs is difficult.

Use an ohmmeter to measure the resistance on the plug contacts of the corresponding sensor; if necessary, replace the sensor.

Prescribed resistance value at +20°C:

• crankshaft pulse sensor: 1.3k Ω
• cylinder ID sensor: between pins 1 and 2: maximum 1 sigma; between contacts 2 and 3: more than 10 M Ω.

Removal the crankshaft pulse sensor

Disconnect the plug connector for the pulse sensor.



Loosen the oil line fastening at the VANOS actuator and plug the holes with clean plugs.





Unscrew the engine suspension eye fastening, while noting the position of wire "1" for its subsequent installation.



Remove the sensor wire from the guides. To do this, unfasten it from the clamps and remove the box for laying the wires, see the figure.



Loosen the mounting screw on the flywheel gear and remove the sensor together with the cover.

Installation

Insert the sensor and tighten the screw to 5 Nm, i.e. quite easily.

Check the gap between the sensor and the toothed wheel with a feeler gauge. The prescribed gap value is 0.7-1.3 mm.

Place the connecting cable back into the guides so that it does not rub against the V-belt. Insert the plug.

Removal the cylinder identification sensor

Remove the upper engine cover, see page 42.



Access to the sensor is difficult. Therefore, the VANOS actuator solenoid valve plug must first be disconnected and the valve removed.

Loosen the oil line fastening at the VANOS actuator and seal the holes with clean plugs, see Figure W-10224.



Loosen the mounting screw and remove the sensor.

Disconnect the sensor plug.

Installation

Insert the sensor. Ensure that the rubber sealing gasket is in the correct position; replace the gasket if necessary.

Tighten the sensor mount to a torque of 5 Nm, i.e. quite easily.

Lay and connect the pilot wire.

Install new sealing rings and tighten the VANOS actuator oil line to 30 Nm.

Screw the solenoid valve into the VANOS actuator and tighten it to a torque of 30 Nm. If necessary, replace the damaged seal first. Connect the plug connector of the solenoid valve.

Install the upper engine cover, see page 42.

This article is based on data from the website «BMWMan.ru»