Electrical/electronic circuit

ELECTRICAL/ELECTRONIC CIRCUIT

Wiring

The system has two distinct sets of wiring. The engine side wiring (A) connects the components fitted on the engine to the engine management control unit, whilst the vehicle side wiring (B), on the other hand, connects the other components to the control unit and acts as an interface with the other vehicle wiring systems.

NOTE The two connectors are the same, therefore if the control unit is being dismantled the fitting position (arrow) must be observed to prevent them being mixed up.

engine side wiring (A)

• butterfly position sensor
• coolant temperature sensor
• air flow meter
• engine rpm sensor
• engine timing sensor
• vehicle speed sensor
• detonation sensor
• injectors
• coils
• idle speed stepping motor
• charcoal filter solenoid valve

vehicle side wiring (B)

• electric fuel pump
• twin relay
• radiator fan relay
• climate control compressor relay (if fitted)
• fuses
• Lambda sensor
• diagnostic equipment
• FIAT CODE control unit
• instrument panel connection
• supply from battery
• supply from ignition switch

Location of system earth points

In order to increase electro-magnetic compatibility and functional reliability, special care has been taken over the number and the location of the earth points, as illustrated in the diagram below:

main earth directly on the battery negative;
engine control system earth on the timing side power unit support.