Fiat Bravo Service Manual page 123

Bravo-Brava @t
12v
Engine
Fuel system
10.
COMPONENTS OF INJECTION-IGNITION SYSTEM
The injection-ignition system consists mainly of wiring, an electronic control unit (i.e. ECU) and the fol­
lowing sensors and actuators:
Sensors
- Speedometer sensor
- Rpm and TDC sensor.
- Knock sensor
- Coolant temperature sensor
- Throttle position sensor
- Intake air temperature sensor
- Lambda probe sensor
Actuators
- Engine idle speed actuator
- Fuel vapour cut-off solenoid
- Electric fuel pump
- Injector
- Ignition coil
- Spark plugs
INJECTION-IGNITION SYSTEM WIRING
The various system components are connected by a single wiring system fitted with connectors of vari­
ous types. These are grouped in special ducts fitted to the engine (prewiring).
INJECTION-IGNITION ECU (0.261.203.868)
The ECU analyses data on engine service conditions transmitted by the sensors. Input signals from pe­
ripheral sensors are processes and injector/ignition timing pulses are governed with the aid of pro­
grammed typical curves.
The ECU is connected to the system by means of a 35 pin connector and protected by false polarities
and circuit-breakers.
The ECU is able to detect when sensors are not working efficiently and replace incorrect or missing data
with data taken from certain areas of its memory in order to ensure engine operation even under emer­
gency conditions. It is also equipped with a full SELF-DIAGNOSTIC strategy for both input and output
sensors. It also contains a special memory able to record any faults received during testing.
When a Fiat/Lancia TESTER is connected to the system it is therefore possible to test or display any er­
rors stored in the memory.
Another important feature of the ECU is self-adaption. This function allows the system to recognise vari­
ous changes (ranging from atmospheric changes to changes due to component wear) which could im­
pair efficient engine operation and adjust to them by implementing appropriate strategies.
Removing-refitting control unit
Disconnect electrical connection. Undo
taining nuts and remove ECU.
re-
Fjnm It is absolutely prohibited to ex-
^ W change injection control units be­
tween different vehicles in order to
check their efficiency.
Before replacing an ECU as a result of
testing, ensure it is really faulty be­
cause when a new ECU is activated,
the secret Fiat CODE system code is
memorised and this makes the unit
completely unusable on other vehi­
cles.
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