Dodge ram truck 3500 1996 Service Manual page 1265

BR
FUEL SYSTEM 14 - 31
DESCRIPTION AND OPERATION (Continued)
Fig. 4 Camshaft Position Sensor—8.0L Engine
sensor, in conjunction with the camshaft position sen­
sor signal, is used to differentiate between fuel Injec­
tion and spark events. I t Is also used to synchronize
the fuel injectors with their respective cylinders.
The sensor is bolted to the cylinder block near the
rear of the right cylinder head (Fig. 5).
Fig. 5 Crankshaft Position Sensor—3.9U5.2U5.9L
Engines—Typicat
Refer to Group 8D, Ignition System for more
crankshaft position sensor information.
The engine will not operate i f the PCM does not
receive a crankshaft position sensor input.
CRANKSHAFT POSITION SENSOR—8.0L
ENGINE—PCM INPUT
This sensor is a hall effect device that detects
notches in the engine crankshaft.
It is used to indicate to the .powertrain control
module (PCM) that a spark and or fuel Injection
event is to be required. The output from this sensor,
in conjunction with the camshaft position -sensor sig­
nal, Is used to differentiate between fuel injection
and spark events. I t Is also used to synchronize the
fuel injectors with their respective cylinders.
The sensor is bolted to the side of the cylinder
block (Fig. 6).
Fig. § Crankshaft Position Sensor—8.0L Engine—
Typical
Refer to Group 8D, Ignition System' for more
crankshaft position sensor Information.
The engine will not operate i f the PCM does not
receive a crankshaft position sensor input. *
ENGINE COOLANT TEMPERATURE SENSOR—3.9L/
5.2L/5.9L ENGINES—PCM INPUT
The engine coolant temperature sensor is installed
next to the thermostat housing (Fig. 7) and protrudes
into the water jacket. The sensor provides an input
voltage to the powertrain control module (PCM)
relating coolant - temperature. The PCM uses this
input along with inputs from other sensors to deter­
mine injector pulse width and' Ignition timing. As
coolant temperature varies, the coolant temperature
sensor resistance will change. This change i n resis­
tance results i n a different input voltage to the PCM.
When the - -engine is cold, * the PCM will operate in
Open Loop cycle. I t will demand slightly richer air-
fuel mixtures and higher idle speeds. This Is done
until normal operating temperatures are reached.
ENGINE COOLANT TEMPERATURE SENSOR—8 J L
ENGINE—PCM INPUT
The engine coolant temperature sensor Is installed
In the thermostat housing (Fig. 8) and protrudes into
the water jacket. The sensor provides an Input volt­
age to the powertrain control module (PCM) relating