Fiat 1998 Marea Weekend, Service Manual

Page: 354 / 846

Marea-Marea Weekend
99 range
m
20v
Engine
Fuel system
10.
1 2 3 4 5
Connector wiring
The numbers indicate the corresponding control
unit pins.
F54
6
+30
F57
L
F 6 3
F25
BUTTERFLY CASING ACTUATOR
The actuator is fixed to the inlet chamber and
regulates the quantity of air drawn in by the en-
gine.
According to the signal coming from the accel-
erator pedal potentiometer, the injection control
unit controls the opening of the butterfly by
means of a direct current motor incorporated in
the butterfly casing actuator.
The butterfly casing actuator has two potenti-
ometers, connected in parallel so that one con-
trols the other and viceversa.
If the two potentiometers fail or if there is no
supply, the control unit reduces the engine
torque depending on the position of the accel-
erator pedal.
The replacement of the butterfly casing actuator
or the injection control unit requires the "self-
learning" procedure described below to be car-
ried out.
- Place the ignition key in the ON position and
keep it there for 30 sees.
- Turn the ignition key to the OFF position for 5
sees.
- Turn the key to the ON position and start up
the engine.
Connector wiring
The numbers indicate the corresponding control
unit pins.
Copyright by Fiat Auto
29