2892602 - E4090 NAVIGATOR - Functional description

Functional description

The optional services relay J60 controls the supply circuit for the navigation system control unit M90 . The coil for relay J60 is energized when the ignition is switched on (INT) by the line for fuse F8 of the junction unit B1 , whilst the supply to the relay contact arrives directly from the battery via the line protected by the maxifuse J/B2 of B5 and by fuse B14 . The relay, controlled by the ignition (INT), supplies the control unit M90 to pin 3 of connector B; pin 2 of connector B is supplied directly by the line protected by the maxifuse J/B2 of B5 and by fuse B14 .

Connectors A and B of M90 are connected to the feeder:

  • pins 2 and 3 of connector B, as seen, receive supplies;
  • pin 1 of the connector is connected to the vehicle earth.
  • pin 4 of connector B receives the signal for auto-activation controlled by the opening of the driver's door: the signal comes from the switch in the front door I16.
Connector A of the feeder is then connected with the actual control unit M90 to connector D, providing signals at various voltages levels and stable earths. Connector C of M90 is for the GPS receiver inside the control unit which is connected with the GPS aerial P29 . Connector E of M90 is for the outputs - audio and video - for the monitor E65 : in reality, the connection takes place through a junction unit in the centre of the dashboard, from where two specific connections for the two, identical monitor mounting bases, positioned, one opposite the driver and the other more centrally, depart.

Connector F for M90 is for the signals received from the other vehicle systems:

  • at pin 7 of connector F the control unit receives the speedometer signal, coming from the instrument panel E50
  • at pin 5 of connector F the reverse gear engaged signal ( See E2022  REVERSING LIGHTS) arrives
  • the pin for connector F provides the earth for the speedometer signal

Connector G for M90 is for connection with the radio P20:

  • a signal leaves pin 9 of connector G for the MUTE function (the volume of the radio is switched off or turned down when the navigation system issues voice messages).
  • pin 1 of connector G is earthed
Connector H of M90 is connected to an earth point on the control unit bracket.