E4020 Tachometer (Manual gearbox)

Description

The module includes the electronic rev counter and a series of warning lights.

The engine management unit (specific to each version) produces an rpm signal. The gauge display is produced by an electronic circuit inside the module.

The following warning lights are contained in this module:

• left turn signals
• right turn signals
• recharging
• minimum oil pressure
• injection system failure
• light failure (check)
• main beam headlamps
• side lights/dipped beams
• rear fog lamps
• fog lights
• trailer lights (preparation)

The rev counter module also contains the check device for the exterior lights which controls the circuits for the side and number plate lights, the rear fog lamps and the brake lights.

The operation of the warning lights which are not included in other functions are illustrated; the others are described and illustrated in the diagrams relating to the components to which they refer.

The rev counter operates when the ignition is switched ON.

In the "night" position (side lights on), the brightness can be adjusted to three levels by an external button. ( Wiring diagram E2530 INSTRUMENT LIGHTING ).

Description of operation

The supply for the rev counter module E15 reaches pins 10 and 16 of connector A directly from the battery. (maxifuse J/B2 of B5 up to 2/99 or of B99 from 2/99), through fuses F2 and F3 of junction unit B1; this supply is used by the check device for the exterior lights ( Wiring diagram E2010 SIDE LIGHTS / NUMBER PLATE , Wiring diagram E2021 STOP LIGHT , Wiring diagram E2031 REAR FOG LAMP ).

The rev counter module E15 also receives a supply controlled by the ignition (INT) at pin 15 of connector B from the line protected by fuse B11 up to 2/99 or fuse F4 of the additional fuse box B98B from 2/99. Pin 14 of connector B is earthed.

The engine rpm signal, which is different for each engine type, comes from the engine management control unit M10 to pin 6 of connector B.

Insufficient engine oil pressure is signalled at pin 5 of connector B of module E15 by the earth signal coming from sensor K30.

For all the other warning lights, refer to the diagrams relating to the components to which they refer.

Wiring diagram

Components

Component location