Rpm signal check

Prepare the diagnostic equipment to download a voltage graph.

Select the VOLTMETER function from the INSTRUMENT menu with the time base set at 5 seconds

Disconnect the connector for the control unit side sensor wiring and leave it disconnected.

Connect the probes across pins 1 and 2 of the sensor.

Press the START button on the diagnostic equipment to begin downloading a graph.

Crank the engine for at least 5 seconds and check that the signal amplitude is greater than 1.5 V and conforms to the attached graph.

Replace the rpm sensor

Op. 5510C26 ENGINE RPM SENSOR - R+R

If the signal is OK, check the continuity/insulation of the wiring between the sensor and engine control unit.

Check that the gap between the sensor and phonic wheel is between 0.5 and 1.5 mm. If it is not OK, restore the correct distance.

If OK, replace the engine control unit

Op. 1056B82 INJECTION/IGNITION SYSTEM E.C.U. (ONE) - R + R