BMW 318/325/M3/525/535/M5 1989-1993 Repair Information

Engine Speed Sensor


The engine speed sensor provides the DME unit with engine speed information. The sensor reads the information from a tooth wheel mounted on the crankshaft hub except on the S14 engine. It can also be called the crankshaft sensor.

The S14 engines speed sensor is mounted next to the cylinder identifying sensor and is removed in the same manner as the cylinder identifying sensor. The sensor on the S14 engine connects to a plug mounted in a group of 3 plugs on the engine compartment rear wall, next to the engine harness connector and diagnosis socket. It is the connector on the right side.


See Figure 1

Click image to see an enlarged view

Fig. Fig. 1: Engine speed sensor mounting-M50 engine

  1. Turn the ignition switch OFF .
  3. Unplug the connector.
  5. Unscrew the bolt holding the sender to the engine. Withdraw the sender from the holder.
  7. Unclip the lead from the lead guide and remove sender from the vehicle.

To install:
  1. Replace the sender and check that it is properly seated. Tighten the mounting bolts to 4.5-5.5 ft. lbs. (6-8 Nm).
  3. Replace the lead in the lead guide and plug in the connector. Make sure that the lead can not rub on the drive belt.