Dodge ram truck 3500 1996 Service Manual page 639

BR 8W - 30 FUEL/IGNITION SYSTEMS
8 W . - 3 0 - 5
DESCRIPTION AND OPERATION (Continued)
HELPFUL INFORMATION
Refer to Group 14 for'MAP sensor operation.
Circuit KB splices to supply 5 volts to the Throttle
Position Sensor (TPS), camshaft position sensor, and
crankshaft position sensor.
Circuit K4 splices to supply ground for the signals
from the following:
• Heated oxygen sensors
® Camshaft position sensor
© Crankshaft position sensor
• Intake air temperature sensor
• Throttle position sensor
• Engine coolant temperature sensor
• Vehicle speed sensor
INTAKE AIR TEMPERATURE SENSOR
The intake air temperature sensor provides an
input to the Powertrain Control Module (PCM) on
circuit K21. Circuit K21 connects to cavity A15 of the
PCM.
From circuit K21, the intake air temperature sen­
sor draws voltage from the PCM. The sensor is a
variable resistor. As intake air temperature changes,
the resistance in the sensor changes, causing a
change in current draw.
The PCM provides a ground for the intake air tem­
perature sensor signal (circuit K21) through circuit
K4. Circuit K4 connects to cavity A4 of the PCM.
HELPFUL INFORMATION
Circuit K4 splices to supply ground for the signals
from the following:
• Heated oxygen sensors
• Camshaft position sensor
• Crankshaft position sensor
• Throttle position sensor
• Manifold absolute pressure sensor
® Engine coolant temperature sensor
• Vehicle speed sensor
PARK/NEUTRAL POSITION SWITCH
When closed, the case-grounded Park/Neutral posi­
tion switch provides a ground path on circuit T41 for
the coil side of the engine starter motor relay. Circuit
A41 from the ignition switch provides battery voltage
to the coil side of the relay.
Circuit T41 splices to cavity A6 of the Powertrain
Control Module (PCM). The Park/Neutral position
switch provides an input to the PCM.
HELPFUL INFORMATION . .
• In the START position, the ignition switch con­
nects circuit A l from the power distribution center
(PDC) to circuit A41. A 40 amp fuse i n cavity 3 of the
PDC protects circuits A l and A41.
• The Park/Neutral position switch and back-up
lamp switch are molded together.
FUEL INJECTORS
When the Automatic Shut Down (ASD) relay con­
tacts close, they connect circuits A16 and A142. Cir­
cuit A142 supplies voltage to the fuel injectors. Each
injector has a separate ground circuit controlled by
the Powertrain Control Module (PCM).
Circuit K l l provides ground for injector number
one. The K l l circuit connects to cavity B4 of the
PCM.
Circuit K12 provides ground for injector number
two. The K12 circuit connects to cavity B15 of the
PCM.
Circuit K13 * provides ground for injector number
three. The K13 circuit connects to cavity B5 of the
PCM.
Circuit K14 provides ground for injector number
four. The K14 circuit connects to cavity B16 of the
PCM.
Circuit K38 provides ground for injector number
five. The K38 circuit connects to cavity B6 of the
PCM.
' Circuit K58 provides ground for injector number
six. The K58 circuit connects to cavity B12 of the
PCM.
On the 5.2L and 5.9L engines, circuit K26 provides
ground for injector number seven. The K26 * circuit
connects to cavity B2 of the PCM.
Also on the 5.2L and 5.9L engines, circuit K28 pro­
vides ground for injector number eight. The K28 cir­
cuit connects to cavity B13 of the PCM.
HELPFUL INFORMATION
• Circuit A142 splices to supply voltage to the fuel
injectors, ignition coil, PCM, generator, and heated
oxygen sensors.
• For information about fuel injector operation,
refer to Group 14. • ' "
FUEL INJECTORS—V-10 ENGINES
When the Automatic Shut Down (ASD) relay con­
tacts close, they connect circuits A16 and A142. Cir­
cuit A142 supplies voltage to the fuel injectors. The
Powertrain Control Module (PCM) provides the
ground for the injectors.
• Circuit K l l provides * ground for injector number
one. The K l l circuit connects to cavity B4 of the
PCM.
Circuit K12 provides ground for injector number
two. The K12 circuit connects to cavity B15 of the
PCM.
Circuit K13 provides ground for injector number
three. The K13 circuit connects to cavity B5 of the
PCM.
Circuit K14 provides ground for injector number
four. The K14 circuit connects to cavity B16 of the
PCM.