Fiat 1996 Brava Service Manual page 324

Engine
Fuel system
10.
Bravo 0 1 20v
98 range
DIAGNOSTIC SOCKET
The exchange of data between the injec­
tion/ignition control unit and the diagnostic
equipment takes place via a two direction se­
rial line (line K) using the standard Bosch
communication protocol.
The transmission is in positive logic and the
coding takes place via the NRZ method (Non
Return Zero) at a baud rate of 4.8 kbaud (208
us/bit ±5%)
Location of diagnostic socket
The arrow in the diagram shows the location
of the diagnostic socket.
INJECTION/IGNITION SYSTEM COMPONENTS
The injection/ignition system basically consists of wiring, an electronic control unit (I.E. control unit)
and the following sensors/actuators:
Sensors
- Speedometer sensor
- Rpm and T.D.C. sensor
- Detonation sensors
- Coolant temperature sensor
- Timing sensor
- Butterfly valve position sensor (integrated
in the butterfly casing actuator)
- Intake air temperature sensor
- Intake air temperature and flow rate sensor
(flow meter)
- Lambda sensor
- Accelerator pedal potentiometer
- Brake pedal switch
- Clutch pedal switch
Actuators
- Butterfly casing actuator
- Phase transformer solenoid valve
- Fuel vapour cut out solenoid valve
- Variable geometry manifold solenoid valve
- Electric fuel pump (including filter and
pressure regulator)
- Injectors
- Ignition coils
- Spark plugs
INJECTION/IGNITION SYSTEM WIRING
The various system components are connected by two distinct sets of wiring.
The engine side wiring (connector M) connect the components fitted on the engine to the injection con­
trol unit; the vehicle side wiring (connector F) connects the other components to the control unit and con­
stitutes the interface with the other vehicle wiring.
The two connectors (M and F) are the same and both have 64 pins, but due to the presence of special
keys it is not possible to mix up the control unit connector wiring.
INJECTION/IGNITION ELECTRONIC CONTROL UNIT
The injection/ignition electronic control unit is located in the engine compartment, fixed to a bracket to
the side of the inlet manifold.
The control unit processes the signals coming from the various sensors through the application of soft­
ware algorhythms and operates the actuators (in particular the injectors and the pressure regulator) in
order to ensure the optimum engine operation.
The control unit is the "flash E.P.R.O.M." type which can be reprogrammed from the outside without in­
volving the hardware.
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