2002 CHRYSLER CARAVAN sensor

SYSTEM DIAGNOSIS
OPERATION
The PCM can test many of its own input and out-
put circuits. If the PCM senses a fault in a major
system, the PCM stores a Diagnostic Trouble Code
(DTC) in memory.For DTC information see On-Board Diagnostics
(Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/POWERTRAIN CONTROL MOD-
ULE - DESCRIPTION) .
SPECIFICATIONS
TORQUE
DESCRIPTION N´m Ft. Lbs. In. Lbs.
MAP SENSOR PLASTIC
MANIFOLD1.7 15
MAP SENSOR
ALUMINUM MANIFOLD3.3 30
POWER STEERING
RESERVOIR PLASTIC
MANIFOLD5.7 50
POWER STEERING
RESERVOIR ALUMINUM
MANIFOLD11.9 105
THROTTLE CABLE
BRACKET PLASTIC
MANIFOLD5.7 50
THROTTLE CABLE
BRACKET ALUMINUM
MANIFOLD11.9 105
EGR TUBE PLASTIC
MANIFOLD5.7 50
EGR TUBE ALUMINUM
MANIFOLD11.9 105
THROTTLE BODY BOLTS
2.4L28 20.65 250  50
THROTTLE BODY BOLTS
3.3/3.8L11.8 8.7 105  20
O2 Sensors 27 20
The composite manifolds uses special Plastic screws. The factory installed Plastic screws can be removed and
installed up to 5 times. Do not exceed the specified torque. These screws must be installed slowly (less than 600
rpms) to avoid melting the parent material. There are service repair screws avialable for repair. They require a
higher torque than the original screws..
RSFUEL INJECTION14-21
FUEL INJECTION (Continued)
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SPECIAL TOOLS
FUEL
ACCELERATOR PEDAL
REMOVAL
(1) Hold the throttle body throttle lever in the
wide open position. Remove the throttle cable from
the throttle body cam (Fig. 1).
(2) From inside the vehicle, hold up the pedal and
remove the pedal retainer and throttle cable from the
upper end of the pedal lever (Fig. 2).
(3) Remove nuts from accelerator pedal attaching
studs. Remove assembly from vehicle (Fig. 3).
Pressure Gauge Assembly C±4799±B
Fuel Pressure Test Adapter 6539
Spanner Wrench 6856
Fuel Line Adapter 1/4
O2S (Oxygen Sensor) Remover/InstallerÐC-4907
O2S(Oxygen Sensor) Remover/Installer - 8439
Fig. 1 THROTTLE CABLE RELEASE
14 - 22 FUEL INJECTIONRS
FUEL INJECTION (Continued)
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INSTALLATION
(1) Position accelerator pedal assembly on dash
panel. Install retaining nuts. Tighten retaining nuts
to 12 N´m (105 in. lbs.) torque (Fig. 3).
(2) From inside the vehicle, hold up the pedal and
install the throttle cable and pedal retainer in the
upper end of the pedal lever (Fig. 2).
(3) From the engine compartment, hold the throt-
tle body lever in the wide open position and install
the throttle cable (Fig. 1).
CRANKSHAFT POSITION
SENSOR
DESCRIPTION
The 2.4L crankshaft sensor is located on the rear
of the engine near the accessory drive belt (Fig. 4).
The 3.3/3.8L crankshaft sensor is located on the rear
of the transmission housing, above the differential
housing (Fig. 5). The bottom of the sensor is posi-
tioned next to the drive plate.
Fig. 2 CABLE CLIP
Fig. 3 ACCELERATOR PEDAL
Fig. 4 CRANKSHAFT SENSOR 2.4L
Fig. 5 CRANKSHAFT SENSOR 3.3/3.8L
RSFUEL INJECTION14-23
ACCELERATOR PEDAL (Continued)
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OPERATION
The crankshaft position sensor detects slots cut
into the transmission driveplate extension (Fig. 6).
There are 3 sets of slots. Each set contains 4 slots,
for a total of 12 slots (Fig. 7). Basic timing is set by
the position of the last slot in each group. Once the
Powertrain Control Module (PCM) senses the last
slot, it determines crankshaft position (which piston
will next be at TDC) from the camshaft position sen-
sor input. The 4 pulses generated by the crankshaft
position sensor represent the 69É, 49É, 29É, and 9É
BTDC marks. It may take the PCM one engine rev-
olution to determine crankshaft position.
The PCM uses crankshaft position reference to
determine injector sequence, ignition timing and the
presence of misfire. Once the PCM determines crank-
shaft position, it begins energizing the injectors in
sequence.
REMOVAL
(1) Disconnect the negative battery cable.
(2) Raise vehicle and support.
(3) Disconnect the electrical connector (Fig. 8).
(4) Remove crankshaft sensor bolt.
(5) Remove the crankshaft sensor.
INSTALLATION - 2.4L
(1) Install the crankshaft sensor.
(2) Install crankshaft sensor bolt and tighten.
(3) Connect the electrical connector (Fig. 8).(4) Lower vehicle.
(5) Connect the negative battery cable.
ENGINE SPEED SENSOR
DESCRIPTION
The PCM receives a signal from the TCM and the
transaxle output speed sensor over the bus communi-
cation line to indicate vehicle speed on automatic
transmission cars. On Manual transmission cars (if
equipped) vehicle, a dedicated vehicle speed sensor is
connected to the PCM.
Fig. 6 Crankshaft Position Sensor
1 - CRANKSHAFT POSITION SENSOR
Fig. 7 Timing Slots
1 - TORQUE CONVERTER DRIVE PLATE
2 - SLOTS
Fig. 8 CRANKSHAFT SENSOR 2.4L
14 - 24 FUEL INJECTIONRS
CRANKSHAFT POSITION SENSOR (Continued)
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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. 9).
OPERATION
The fuel injectors are 12 volt electrical solenoids
(Fig. 10). 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. Thepulse width is controlled by the duration of the
ground path provided.
REMOVAL
REMOVAL - 2.4L
The fuel rail must be removed first (Fig. 11). Refer
to Fuel Rail Removal in this section.
(1) Disconnect injector wiring connector from injec-
tor.
(2) Position fuel rail assembly so that the fuel
injectors are easily accessible (Fig. 12).
(3) Rotate injector and pull injector out of fuel rail.
The clip will stay on the injector.
(4) Check injector O-ring for damage. If O-ring is
damaged, it must be replaced. If injector is reused, a
protective cap must be installed on the injector tip to
Fig. 9 Fuel Injector Location - Typical
1 - FUEL RAIL
2 - INTAKE MANIFOLD
3 - FUEL INJECTORS
Fig. 10 FUEL INJECTOR - TYPICAL
1 - FUEL INJECTOR
2 - NOZZLE
3 - TOP (FUEL ENTRY)
Fig. 11 FUEL RAIL AND INJECTORS 2.4L
1 - Fuel Injectors
2 - Fuel Rail
RSFUEL INJECTION14-25
ENGINE SPEED SENSOR (Continued)
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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. 14) or (Fig. 15).
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, crank-
shaft position sensor, coolant temperature sensor, MAP
sensor, vehicle speed sensor and various switch opera-
tions (brake, park/neutral, air conditioning).
When engine rpm is above idle speed, the IAC is
used for the following functions:
²Off-idle dashpot
²Deceleration air flow control
²A/C compressor load control (also opens the pas-
sage slightly before the compressor is engaged so
that the engine rpm does not dip down when the
compressor engages)
Target Idle
Target idle is determined by the following inputs:
²Gear position
²ECT Sensor
²Battery voltage
²Ambient/Battery Temperature Sensor
²VSS
²TPS
²MAP Sensor
Fig. 14 TPS/IAC 2.4L
1 - Idle Air Control Motor
2 - Throttle Position Sensor
Fig. 15 TPS/IAC 3.3/3.8L
1 - Idle Air Control Motor
2 - Throttle Position Sensor
RSFUEL INJECTION14-27
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REMOVAL
When servicing throttle body components, always
reassemble components with new O-rings and seals
where applicable. Never use lubricants on O-rings or
seals, damage may result. If assembly of component
is difficult, use water to aid assembly. Use care when
removing hoses to prevent damage to hose or hose
nipple.
(1) Disconnect negative cable from battery.
(2) Remove electrical connector from idle air con-
trol motor.
(3) Remove idle air control motor mounting screws.
(4) Remove motor from throttle body. Ensure the
O-rings is removed with the motor.
INSTALLATION
When servicing throttle body components, always
reassemble components with new O-rings and seals
where applicable. Never use lubricants on O-rings or
seals, damage may result. If assembly of component
is difficult,a light coat of engine oil may be
applied to the O-RINGS ONLY (Fig. 16)to aid
assembly. Use care when removing hoses to prevent
damage to hose or hose nipple.
(1) The new idle air control motor has a new
O-ring installed on it. For 2.4L only, if pintle mea-
sures more than 1 inch (25 mm) it must be retracted.
Use the DRB Idle Air Control Motor Open/Close Test
to retract the pintle (battery must be connected.)
(2) Carefully place idle air control motor into
throttle body.
(3) Install mounting screw(s). Tighten screws to 2
N´m (17 in. lbs.) torque.
(4) Connect electrical connector to idle air control
motor.
(5) Connect negative cable to battery.
INLET AIR TEMPERATURE
SENSOR
DESCRIPTION
The IAT Sensor is a Negative Temperature Coeffi-
cient (NTC) Sensor that provides information to the
PCM regarding the temperature of the air entering
the intake manifold (Fig. 17).
OPERATION
Inlet/Intake Air Temperature
The inlet air temperature sensor replaces the
intake air temperature sensor and the battery tem-
perature sensor. The PCM uses the information from
the inlet air temperature sensor to determine values
to use as an intake air temperature sensor and a bat-
tery temperature sensor.
The Intake Air Temperature (IAT) sensor value is
used by the PCM to determine air density.
The PCM uses this information to calculate:
²Injector pulse width
²Adjustment of ignition timing (to prevent spark
knock at high intake air temperatures)
Battery Temperature
The inlet air temperature sensor replaces the
intake air temperature sensor and the battery tem-
perature sensor. The PCM uses the information from
the inlet air temperature sensor to determine values
for the PCM to use as an intake air temperature sen-
sor and a battery temperature sensor.
The battery temperature information along with
data from monitored line voltage (B+), is used by the
PCM to vary the battery charging rate. System volt-
Fig. 16 O-RINGS
1 - O-rings
Fig. 17 3.3/3.8L IAT SENSOR
14 - 28 FUEL INJECTIONRS
IDLE AIR CONTROL MOTOR (Continued)
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age will be higher at colder temperatures and is
gradually reduced at warmer temperatures.
The battery temperature information is also used
for OBD II diagnostics. Certain faults and OBD II
monitors are either enabled or disabled depending
upon the battery temperature sensor input (example:
disable purge, enable LDP). Most OBD II monitors
are disabled below 20ÉF.
MAP SENSOR
DESCRIPTION
The MAP sensor (Fig. 18) or (Fig. 19) mounts to
the intake manifold. The sensor is connects electri-
cally to the PCM.
OPERATION
The MAP serves as a PCM input, using a silicon
based sensing unit, to provide data on the manifold
vacuum that draws the air/fuel mixture into the com-
bustion chamber. The PCM requires this information
to determine injector pulse width and spark advance.
When MAP equals Barometric pressure, the pulse
width will be at maximum.
Also like the cam and crank sensors, a 5 volt ref-
erence is supplied from the PCM and returns a volt-
age signal to the PCM that reflects manifold
pressure. The zero pressure reading is 0.5V and full
scale is 4.5V. For a pressure swing of0Ð15psithe
voltage changes 4.0V. The sensor is supplied a regu-
lated 4.8 to 5.1 volts to operate the sensor. Like the
cam and crank sensors ground is provided through
the sensor return circuit.
The MAP sensor input is the number one contrib-
utor to pulse width. The most important function of
the MAP sensor is to determine barometric pressure.
The PCM needs to know if the vehicle is at sea level
or is it in Denver at 5000 feet above sea level,
because the air density changes with altitude. It will
also help to correct for varying weather conditions. If
a hurricane was coming through the pressure would
be very, very low or there could be a real fair
weather, high pressure area. This is important
because as air pressure changes the barometric pres-
sure changes. Barometric pressure and altitude have
a direct inverse correlation, as altitude goes up baro-
metric goes down. The first thing that happens as
the key is rolled on, before reaching the crank posi-
tion, the PCM powers up, comes around and looks at
the MAP voltage, and based upon the voltage it sees,
it knows the current barometric pressure relative to
altitude. Once the engine starts, the PCM looks at
the voltage again, continuously every 12 milliseconds,
and compares the current voltage to what it was at
key on. The difference between current and what it
was at key on is manifold vacuum.
During key On (engine not running) the sensor
reads (updates) barometric pressure. A normal range
can be obtained by monitoring known good sensor in
you work area.
As the altitude increases the air becomes thinner
(less oxygen). If a vehicle is started and driven to a
very different altitude than where it was at key On
the barometric pressure needs to be updated. Any
time the PCM sees Wide Open throttle, based upon
TPS angle and RPM it will update barometric pres-
sure in the MAP memory cell. With periodic updates,
the PCM can make its calculations more effectively.
The PCM uses the MAP sensor to aid in calculat-
ing the following:
²Barometric pressure
²Engine load
Fig. 18 MAP SENSOR - 2.4L
Fig. 19 MAP SENSOR - 3.3/3.8L
RSFUEL INJECTION14-29
INLET AIR TEMPERATURE SENSOR (Continued)
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