2003 CHRYSLER CARAVAN fuel pump

1 second. Therefore, battery voltage is not supplied to
the fuel pump, ignition coil, fuel injectors and heated
oxygen sensors.
ENGINE START-UP MODE
This is an OPEN LOOP mode. If the vehicle is in
park or neutral (automatic transaxles) or the clutch
pedal is depressed (manual transaxles) the ignition
switch energizes the starter relay when the engine is
not running. The following actions occur when the
starter motor is engaged.
²If the PCM receives the camshaft position sensor
and crankshaft position sensor signals, it energizes
the Auto Shutdown (ASD) relay and fuel pump relay.
If the PCM does not receive both signals within
approximately one second, it will not energize the
ASD relay and fuel pump relay. The ASD and fuel
pump relays supply battery voltage to the fuel pump,
fuel injectors, ignition coil, (EGR solenoid and PCV
heater if equipped) and heated oxygen sensors.
²The PCM energizes the injectors (on the 69É
degree falling edge) for a calculated pulse width until
it determines crankshaft position from the camshaft
position sensor and crankshaft position sensor sig-
nals. The PCM determines crankshaft position within
1 engine revolution.
²After determining crankshaft position, the PCM
begins energizing the injectors in sequence. It adjusts
injector pulse width and controls injector synchroni-
zation by turning the individual ground paths to the
injectors On and Off.
²When the engine idles within  64 RPM of its
target RPM, the PCM compares current MAP sensor
value with the atmospheric pressure value received
during the Ignition Switch On (zero RPM) mode.
Once the ASD and fuel pump relays have been
energized, the PCM determines injector pulse width
based on the following:
²MAP
²Engine RPM
²Battery voltage
²Engine coolant temperature
²Inlet/Intake air temperature (IAT)
²Throttle position
²The number of engine revolutions since cranking
was initiated
During Start-up the PCM maintains ignition tim-
ing at 9É BTDC.
ENGINE WARM-UP MODE
This is an OPEN LOOP mode. The following inputs
are received by the PCM:
²Manifold Absolute Pressure (MAP)
²Crankshaft position (engine speed)
²Engine coolant temperature
²Inlet/Intake air temperature (IAT)²Camshaft position
²Knock sensor
²Throttle position
²A/C switch status
²Battery voltage
²Vehicle speed
²Speed control
²O2 sensors
The PCM adjusts injector pulse width and controls
injector synchronization by turning the individual
ground paths to the injectors On and Off.
The PCM adjusts ignition timing and engine idle
speed. Engine idle speed is adjusted through the idle
air control motor.
CRUISE OR IDLE MODE
When the engine is at operating temperature this
is a CLOSED LOOP mode. During cruising or idle
the following inputs are received by the PCM:
²Manifold absolute pressure
²Crankshaft position (engine speed)
²Inlet/Intake air temperature
²Engine coolant temperature
²Camshaft position
²Knock sensor
²Throttle position
²Exhaust gas oxygen content (O2 sensors)
²A/C switch status
²Battery voltage
²Vehicle speed
The PCM adjusts injector pulse width and controls
injector synchronization by turning the individual
ground paths to the injectors On and Off.
The PCM adjusts engine idle speed and ignition
timing. The PCM adjusts the air/fuel ratio according
to the oxygen content in the exhaust gas (measured
by the upstream and downstream heated oxygen sen-
sor).
The PCM monitors for engine misfire. During
active misfire and depending on the severity, the
PCM either continuously illuminates or flashes the
malfunction indicator lamp (Check Engine light on
instrument panel). Also, the PCM stores an engine
misfire DTC in memory, if 2nd trip with fault.
The PCM performs several diagnostic routines.
They include:
²Oxygen sensor monitor
²Downstream heated oxygen sensor diagnostics
during open loop operation (except for shorted)
²Fuel system monitor
²EGR monitor (if equipped)
²Purge system monitor
²Catalyst efficiency monitor
²All inputs monitored for proper voltage range,
rationality.
RSFUEL INJECTION14-19
FUEL INJECTION (Continued)
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(2) Install injector clip by sliding open end into the
top slot of the injector. The edge of the receiver cup
will slide into the side slots of clip (Fig. 13).
(3) Install injector top end into fuel rail receiver
cap. Be careful not to damage O-ring during installa-
tion (Fig. 13).
(4) Repeat steps for remaining injectors.
(5) Install fuel rail, refer to Fuel Rail in the Fuel
Delivery section.
(6) Connect fuel injector wiring.
(7) Install the Intake Manifold, (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
INSTALLATION)
(8) Connect the negative battery cable.
FUEL PUMP RELAY
DESCRIPTION
The fuel pump relay is located in the PDC. The
inside top of the PDC cover has a label showing relay
and fuse location.
OPERATION
The fuel pump relay supplies battery voltage to the
fuel pump. A buss bar in the Power Distribution Cen-
ter (PDC) supplies voltage to the solenoid side and
contact side of the relay. The fuel pump relay power
circuit contains a fuse between the buss bar in the
PDC and the relay. The fuse is located in the PDC.
Refer to the Wiring Diagrams for circuit information.
The PCM controls the fuel pump relay by switch-
ing the ground path for the solenoid side of the relay
on and off. The PCM turns the ground path off when
the ignition switch is in the Off position. When the
ignition switch is in the On position, the PCM ener-
gizes the fuel pump. If the crankshaft position sensor
does not detect engine rotation, the PCM de-ener-
gizes the relay after approximately one second.
IDLE AIR CONTROL MOTOR
DESCRIPTION
The idle air control motor is mounted on the throt-
tle body. The PCM operates the idle air control motor
(Fig. 15) or (Fig. 16).
OPERATION
The PCM adjusts engine idle speed through the
idle air control motor to compensate for engine load,
coolant temperature or barometric pressure changes.
The throttle body has an air bypass passage that
provides air for the engine during closed throttle idle.
The idle air control motor pintle protrudes into the
air bypass passage and regulates air flow through it.The PCM adjusts engine idle speed by moving the
IAC motor pintle in and out of the bypass passage.
The adjustments are based on inputs the PCM
receives. The inputs are from the throttle position
sensor, crankshaft position sensor, coolant tempera-
ture sensor, MAP sensor, vehicle speed sensor and
various switch operations (brake, park/neutral, air
conditioning).
When engine rpm is above idle speed, the IAC is
used for the following functions:
²Off-idle dashpot
Fig. 15 TPS/IAC 2.4L
1 - Idle Air Control Motor
2 - Throttle Position Sensor
Fig. 16 TPS/IAC 3.3/3.8L
1 - Idle Air Control Motor
2 - Throttle Position Sensor
14 - 28 FUEL INJECTIONRS
FUEL INJECTOR (Continued)
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INSTALLATION
(1) Verify o-ring is installed into position (Fig.
317).
(2) Install and tighten input speed sensor to 27
N´m (20 ft. lbs.).
(3) Connect speed sensor connector.
(4) Connect battery negative cable.
TORQUE CONVERTER
DESCRIPTION
The torque converter (Fig. 318) is a hydraulic
device that couples the engine crankshaft to the
transmission. The torque converter consists of an
outer shell with an internal turbine, a stator, an
overrunning clutch, an impeller and an electronically
applied converter clutch. The converter clutch pro-
vides reduced engine speed and greater fuel economy
when engaged. Clutch engagement also provides
reduced transmission fluid temperatures. The con-
verter clutch engages in third gear. The torque con-
verter hub drives the transmission oil (fluid) pump.
The torque converter is a sealed, welded unit that
is not repairable and is serviced as an assembly.
Fig. 316 Output Speed Sensor
1 - OUTPUT SPEED SENSOR
Fig. 317 O-ring Location
1 - OUTPUT SPEED SENSOR
2 - O-RINGFig. 318 Torque Converter Assembly
1 - TURBINE
2 - IMPELLER
3 - HUB
4-STATOR
5 - CONVERTER CLUTCH DISC
6 - DRIVE PLATE
21 - 242 41TE AUTOMATIC TRANSAXLERS
SPEED SENSOR - OUTPUT (Continued)
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DIESEL SUPPLEMENTAL HEATER - DCHA - EXPORT
TABLE OF CONTENTS
page page
DIESEL SUPPLEMENTAL HEATER - DCHA -
EXPORT
DESCRIPTION........................106
OPERATION
OPERATION........................106
OPERATION - TWO ZONE ATC..........106
DIAGNOSIS AND TESTING - DIESEL
SUPPLEMENTAL HEATER - DCHA.......107
EXHAUST TUBE
REMOVAL............................107
INSTALLATION........................107
FUEL DOSING PUMP
DESCRIPTION........................108
OPERATION..........................108
REMOVAL............................108INSTALLATION........................108
FUEL LINE
STANDARD PROCEDURE - CLEANING.....109
REMOVAL............................109
INSTALLATION........................110
HEATER UNIT
REMOVAL............................111
INSTALLATION........................111
SUPPLEMENTAL DIESEL HEATER WIRING
REMOVAL............................112
INSTALLATION........................112
AIR INTAKE PIPE
REMOVAL............................112
INSTALLATION........................113
DIESEL SUPPLEMENTAL
HEATER - DCHA - EXPORT
DESCRIPTION
Vehicles equipped with the optional diesel engine
are also equipped with a supplemental heater unit.
This unit is mounted under the vehicle and operates
similar to an oil fired furnace. The heater burns
small amounts of fuel to provide additional heat to
the coolant. Coolant is routed from the engine, to the
supplemental heater, and then to the front heater
core. This provides additional heat to the passenger
compartment. The system is interfaced to the vehi-
cles on-board computer systems and DRB-III diag-
nostics.
The supplemental heater unit has a electronic con-
trol unit that monitors the heat output of the heater.
The heater operates at full load (5 kW), half load or
idle mode (no additional heat) depending on collant
temperature.
OPERATION
OPERATION
The supplemental heater unit is activated via the
temperature slide control or knob on the vehicle
HVAC control unit. If the control slide or knob is
moved to or above the upper set point the heater is
activated. The unit can operate in a full or partial
load range as well as an idle mode all dependent on
the engine coolant temperature. The heater unit willalso turn off if the HVAC temperature control is low-
ered to less than the lower set point. The heater unit
can take up to three minutes to completely shut
down when either the heater temperature is set
below the lower set point or the vehicle ignition is
shut down.
The supplemental heater only operates when the
engine is running, the mileage exceeds 8 kilometer (5
mph) and the fuel tank volume exceeds 1/8 of a tank.
The heater should start if the collant temperature is
below 40 degrees celsius (104 degrees F).
NOTE: Do not apply a strong vacuum directly on
the supplemtal heater exhaust line. Place the vac-
uum within 75 mm (3 inches) of the exhaust port.
Too strong of a vacuum can prevent the heater from
starting. The heater ECU monitors the supplemental
blower speed and combustion during its start-up.
OPERATION - TWO ZONE ATC
The Two Zone ATC control head will activate the
Supplemental Heater based on engine coolant tem-
perature and interior component settings. The unit
can operate in a full or partial load range as well as
an idle mode all dependent on the engine coolant
temperature. The unit will also turn off if the HVAC
temperature control setting is lowered to less than
the lower set point. The unit can take up to three
minutes to completely shut down when either the
heater temperature is set below the lower set point of
the vehicle ignition is shut down.
24 - 106 DIESEL SUPPLEMENTAL HEATER - DCHA - EXPORTRS
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(5) Check exhaust pipe exhaust end placement and
make any final adjustments.
(6) Lower vehicle from lift.
FUEL DOSING PUMP
DESCRIPTION
The dosing pump is a combined delivery, dosing
and shut-off system for the fuel supply to the heater
from the vehicles fuel tank.
OPERATION
The dosing pump is an electrically operated pump
that receives its operation instructions from the sup-
plemental heater electronic control module. The
pump supplies diesel fuel from the fuel tank to the
heater unit.
REMOVAL
The dosing pump is serviceable without removing
the component from the vehicle.
(1) Disconnect the rubber hose at the fuel line to
heater fuel pump. Leave the rubber hose on the fuel
line.(Refer to 24 - HEATING & AIR CONDITION-ING/CABIN HEATER/FUEL LINE - REMOVAL)
(Fig. 2).
(2) Disconnect the fuel line between the dosing
pump and the heater unit.
NOTE: Position and retain heater fuel line to pre-
vent fuel leakage while servicing dosing pump.
NOTE: Utilize an approved fuel storage container to
catch any residual fuel.
(3) Disconnect the electrical connector to the fuel
pump by depressing the integral spring and pulling
the connector away from the pump.
(4) Remove the dosing pump from the rubber iso-
lation.
INSTALLATION
(1) Mount the rubber isolation back onto the
splash shield mounting flanges at two locations.
(2) Connect fuel lines to the dosing pump and the
heater unit. The connectors should point towards the
heater fuel line.
(3) Use aviation style clamps to attach the hose to
the fuel pump nipples(Refer to 24 - HEATING & AIR
Fig. 1 Diesel Cabin Heater Exhaust System
1 - Mounting screws (3)
2 - Steel heater exhaust pipe
3 - Exhaust clamp (2)4 - Flexible heater exhaust pipe
5 - Heater and heater shield
6 - Exhaust pipe mounting clips (3) (If Equipped)
24 - 108 DIESEL SUPPLEMENTAL HEATER - DCHA - EXPORTRS
EXHAUST TUBE (Continued)
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CONDITIONING/CABIN HEATER/FUEL LINE -
INSTALLATION).
(4) Connect the electrical connector to the fuel
pump by depressing the integral spring and pushing
the connector towards the dosing pump. Pull the con-
nector towards the heater to verify the installation.
(5) Verify function of the heater.
FUEL LINE
STANDARD PROCEDURE - CLEANING
(1) Remove the cabin heater fuel line(Refer to 24 -
HEATING & AIR CONDITIONING/CABIN HEAT-
ER/FUEL LINE - REMOVAL).
(2) With cabin heater line removed from vehicle
place a shop cloth on the fuel tank end of the fuel
line to catch any residue, then apply a small amount
of air pressure to the other end of the fuel line.
(3) Check to see if air pressure is coming from the
tank end of the line. If pressure is flowing unre-
stricted the line is clean.
(4) If the line shows any signs of being restricted
after air pressure is applied, then the fuel line should
be replaced.(5) Install the cabin heater line(Refer to 24 -
HEATING & AIR CONDITIONING/CABIN HEAT-
ER/FUEL LINE - INSTALLATION).
(6) Verify function of the heater.
REMOVAL
(1) Elevate vehicle on a lift taking note of the
heater exhaust tube flexible section.
(2) Remove clamps on dosing pump end of fuel line
and separate line from pump (Fig. 3).
NOTE: Have an approved fuel holding device ready
to capture any diesel fuel that drains from fuel line
or heater unit.
(3) Remove clamp from fuel line at fuel tank con-
nection and separate line from tank.
(4) Remove any retaining clips and remove line
from vehicle.
Fig. 2 Dosing Pump Fuel Line
1 - Fuel Line
2 - Retaining Clamps3 - Dosing Pump
4 - Heater Unit Air Intake Pipe
RSDIESEL SUPPLEMENTAL HEATER - DCHA - EXPORT24 - 109
FUEL DOSING PUMP (Continued)
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INSTALLATION
WARNING: DO NOT OPERATE THE DCHA IN AN
ENCLOSED AREA SUCH AS A GARAGE THAT
DOES NOT HAVE EXHAUST VENTILATION FACILI-
TIES. ALWAYS VENT THE DCHA'S EXHAUST WHEN
OPERATING THE DCHA. FAILURE TO FOLLOW
THESE INSTRUCTIONS MAY RESULT IN PERSONAL
INJURY OR DEATH.
WARNING: ALLOW THE DCHA ASSEMBLY TO
COOL BEFORE PERFORMING A COMPONENT
INSPECTION/REPAIR/REPLACEMENT. FAILURE TO
FOLLOW THESE INSTRUCTIONS MAY RESULT IN
PERSONAL INJURY.
WARNING: VERIFY THAT ALL DCHA FUEL LINES
ARE SECURELY FASTENED TO THEIR RESPECTIVE
COMPONENTS BEFORE PERFORMING THIS PRO-
CEDURE.
NOTE: Verify that there is more than 1/8 of a tank of
fuel in the vehicle's fuel tank before performing this
procedure. Add fuel, if necessary.(1) Install heater fuel supply line to vehicle and
install in fuel line retainers
(2) Install fuel line connection at fuel tank and
tighten connection.
(3) Install fuel line at Dosing Pump and tighten
connection.
(4) Lower vehicle from lift.
NOTE: Failure to prime the Dosing Pump after
draining the DCHA fuel line will prevent DCHA
heater activation during the first attempt to start the
heater. This will also set a Diagnostic Trouble Code
(DCT) in the DCHA Control's memory. Do not per-
form the Dosing Pump Priming procedure if an
attempt was made to start the DCHA without prim-
ing the Dosing Pump first. This will put excess fuel
in the DCHA Heater Module and cause smoke to
emit from the DCHA exhaust pipe when heater acti-
vation occurs.
(5) Connect the DRBIIItto the Diagnostic Link
Connector.
(6) Turn the ignition to the on position.
Fig. 3 Dosing Pump Fuel Line
1 - Fuel Line
2 - Retaining Clamps3 - Dosing Pump
4 - Heater Unit Air Intake Pipe
24 - 110 DIESEL SUPPLEMENTAL HEATER - DCHA - EXPORTRS
FUEL LINE (Continued)
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NOTE: Do not activate the Dosing Pump Prime
more than one time. This will put excess fuel in the
DCHA Heater Module an cause smoke to emit from
the DCHA exhaust pipe when heater activation
occurs.
NOTE: A clicking noise heard coming from the Dos-
ing Pump indicates that the pump is operational.
(7) With the DRBIIItin Cabin Heater, select Sys-
tem Tests and Dosing Pump Prime. Allow the Dosing
Pump to run for the full 45 second cycle time. When
the 45 second cycle is complete, press Page Back on
the DRBIIItkey pad to exit the Dosing Pump Prime.
The Dosing Pump priming procedure is now com-
plete.
HEATER UNIT
REMOVAL
WARNING: ALLOW THE DCHA TO COOL BEFORE
PERFORMING A COMPONENT INSPECTION/REPAIR
OR REPLACEMENT. FAILURE TO FOLLOW THESE
INSTRUCTIONS MAY RESULT IN PERSONAL
INJURY.
WARNING: ALLOW THE EXHAUST SYSTEM TO
COOL BEFORE PERFORMING A COMPONENT
INSPECTION/REPAIR OR REPLACEMENT. FAILURE
TO FOLLOW THESE INSTRUCTION MAY RESULT IN
PERSONAL INJURY.
(1) Elevate the vehicle on a hoist/lift taking note of
heater exhaust tube flexible section.
(2) Drain cooling system(Refer to 7 - COOLING -
STANDARD PROCEDURE).
(3) Carefully open one hose to the underbody tube
assembly and drain the remaining coolant. A salvage
hose is a good idea to control the residual coolant, as
flow will occur from both the heater and the hose and
tube assemblies.
(4) Remove the second hose from the underbody
hose and tube assembly.
(5) Loosen the hose and tube assembly from the
toe-board cross member at two locations.
(6) Disconnect the electrical connector from the
body harness near the toe board cross member and
rail.
(7) Remove the wiring harness from the toe board
cross member(Refer to 24 - HEATING & AIR CON-
DITIONING/CABIN HEATER/HEATER UNIT -
REMOVAL).
(8) Open the fuel fill cap. Disconnect the rubber
fuel hose between the body tube assembly and thefuel pump nipple at the body tube joint. A minimal
amount of fuel may flow from the open port.
NOTE: Utilize an approved fuel storage container to
catch any residual fuel.
(9) Loosen the two M8 fasteners at the rail. Take
care to notice that the exhaust tube bracket tab is on
top of the heater bracket and that there are (2)
spacer washers installed between the rubber grom-
mets.
(10) Remove the heater exhaust tube flex section
from the exhaust tube by loosening the M6 bolt of
the clamp assembly. Remove the hose from the
exhaust tube. Removal of the rail tube assembly may
aid in this service operation.(Refer to 24 - HEATING
& AIR CONDITIONING/CABIN HEATER/EXHAUST
TUBE - REMOVAL).
(11) Remove seat hex nut at the heater mounting
flange to cross member.
(12) Loosen the remaining M6 and M8 fasteners
which mount the exhaust tube assembly to the vehi-
cle.
(a) Install a suitable cabin heater support device
under the cabin heater and secure the cabin heater
to the device.
(13) Loosen the remaining three M6 fasteners to
the cross members.
(14) Remove the loosened fasteners that support
the heater while supporting the weight of the heater.
(15) Swing the unit mounting bracket from
between the exhaust bracket and rail mounting loca-
tion. Drain any residual coolant from the heater unit.
(16) Lower the cabin heater and remove from the
supporting device and place on a suitable work area.
INSTALLATION
(1) Install the unit mounting bracket between the
exhaust bracket and the rail mounting location.
(2) Install the fasteners that support the heater
while supporting the weight of the heater.
(3) Install the three M6 fasteners to the cross
members. Tighten the M6 fasteners to 7 Nm (5 ft.
lbs.).
(4) Position the two spacer washers between the
body and the rubber grommets for the two M8
mounting points on the rail.
(5) Tighten the remaining M6 fasteners to 7 Nm (5
ft. lbs.) and the M8 fasteners to 23 Nm (17 ft. lbs.)
which mount the exhaust tube assembly to the vehi-
cle.
(6) Install the seat hex nut at the heater mounting
flange to the cross members. Tighten to 60 Nm (44 ft.
lbs.)
(7) Install the heater exhaust tube flex section to
the exhaust tube by tightening the M6 bolt of the
clamp assembly. Install the hose to the exhaust tube.
RSDIESEL SUPPLEMENTAL HEATER - DCHA - EXPORT24 - 111
FUEL LINE (Continued)
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