Fiat 1998 Marea Weekend, Service Manual

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Marea-Marea Weekend®
99 update
lev
Engine
Fuel system
10.
IGNITION COIL
The ignition circuit is the inductive discharge,
static advance type where the high voltage is
supplied by four coils fitted directly on the
spark plugs (pencil-coils).
The coil used is the closed magnetic circuit
type, with the windings in a plastic container
immersed in epoxide resin. The coil is con-
nected directly to the spark plug by means of a
silicon extension which has good dielectric
properties.
The coil incorporates a power transistor for in-
terrupting the primary winding.
The primary winding of each coil is supplied
by the battery voltage (+30) by means of the
twin relay and is connected to earth via the
built in power transistor whose base is con-
nected to the control unit pin.
3N34GJ01
Interrupting the current to the base of the transistor interrupts the connection to earth of the primary
winding and, as a result, causes the high tension discharge at the secondary winding.
The optimum ignition advance is calculated by the control unit according to the engine speed and load
conditions and is implemented in the form of time between the TDC for the explosion stroke and the mo-
ment the supply in the coil primary winding is interrupted.
Wiring connector
1. Cylinder 1 ignition coil
2. Cylinder 2 ignition coil
3. Cylinder 3 ignition coil
4. Cylinder 4 ignition coil
5. Interface connector
6. Engine earth
7A 8A 9A 10A
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