Chrysler Sebring 2005 Service Manual page 1359

14 - 24 FUEL INJECTION
ENGINE SPEED SENSOR
DESCRIPTION
The PCM receives a signal from the TCM to indi-
cate vehicle speed on automatic transmission cars.
On 4 cylinder Manual transmission cars (if equipped)
vehicle, a dedicated vehicle speed sensor is connected
to the PCM.On V-6 Manual transmission cars (if
equipped) vehicle, the ABS module provides the sig-
nal to the PCM for vehicle speed.
OPERATION
The Transmission Control Module (TCM) supplies
the road speed and distance traveled inputs to the
PCM. From these inputs and the throttle position
sensor input, the PCM determines when a decelera-
tion condition occurs.
FUEL INJECTOR
DESCRIPTION
The injectors are positioned in the intake manifold
or cylinder head with the nozzle ends directly above
the intake valve port (Fig. 10).
Fig. 10 Fuel Injector Location - Typical
1 - FUEL RAIL
2 - INTAKE MANIFOLD
3 - FUEL INJECTORS
OPERATION
The fuel injectors are 12 volt electrical solenoids
(Fig. 11). The injector contains a pintle that closes off
an orifice at the nozzle end. When electric current is
supplied to the injector, the armature and needle
move a short distance against a spring, allowing fuel
to flow out the orifice. Because the fuel is under high
pressure, a fine spray is developed in the shape of a
hollow cone or two streams. The spraying action
atomizes the fuel, adding it to the air entering the
combustion chamber. Fuel injectors are not inter-
changeable between engines.
The PCM provides battery voltage to each injector
through the ASD relay. Injector operation is con-
trolled by a ground path provided for each injector by
the PCM. Injector on-time (pulse-width) is variable,
and is determined by the PCM processing all the
data previously discussed to obtain the optimum
injector pulse width for each operating condition. The
pulse width is controlled by the duration of the
ground path provided.
Fig. 11 FUEL INJECTOR - TYPICAL
1 - FUEL INJECTOR
2 - NOZZLE
3 - TOP (FUEL ENTRY)
REMOVAL
REMOVAL - 4 CYLINDER
The fuel rail must be removed first (Fig. 12). Refer
to Fuel Rail Removal in this section.
Fig. 12 FUEL RAIL AND INJECTORS
1 - Fuel Injectors
2 - Fuel Rail
JR