2003 CHRYSLER CARAVAN oil temperature

OPERATION
A mechanical sensor in the expansion valve control
head monitors the temperature and pressure of the
refrigerant leaving the evaporator coil through the
suction line, and adjusts the orifice size at the liquid
line to let the proper amount of refrigerant into the
evaporator coil to meet the vehicle cooling require-
ments. Controlling the refrigerant flow through the
evaporator ensures that none of the refrigerant leav-
ing the evaporator is still in a liquid state, which
could damage the compressor.
DIAGNOSIS AND TESTING - EXPANSION VALVE
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT - WARNING - A/C PLUMBING)
and (Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT - CAUTION - A/C PLUMBING).
NOTE: The expansion valve should only be tested
following testing of the compressor.
NOTE: Liquid CO
2is required to test the expansion
valve. This material is available from most welding
supply facilities. Liquid CO
2is also available from
companies which service and sell fire extinguish-
ers.
When testing the expansion valve, the work area
and the vehicle temperature must be 21É to 27É C
(70É to 85É F). To test the expansion valve:
(1) Connect a charging station or manifold gauge
set to the refrigerant system service ports. Verify the
refrigerant charge level.
(2) Close all doors, windows and vents to the pas-
senger compartment.
(3) Set the heater-air conditioner controls so that
the compressor is operating, the temperature control
is in the highest temperature position, the mode door
is directing the output to the floor outlets, and the
blower is operating at the highest speed setting.
(4) Start the engine and allow it to idle at 1000
rpm. After the engine has reached normal operating
temperature, allow the passenger compartment to
heat up. This will create the need for maximum
refrigerant flow into the evaporator.
(5) If the refrigerant charge is sufficient, the dis-
charge (high pressure) gauge should read 965 to 1655
kPa (140 to 240 psi). The suction (low pressure)
gauge should read 140 kPa to 207 kPa (20 psi to 30
psi). If OK, go to Step 6. If not OK, replace the faulty
expansion valve.WARNING: PROTECT THE SKIN AND EYES FROM
EXPOSURE TO LIQUID CO
2. PERSONAL INJURY
CAN RESULT.
(6) If the suction (low pressure) gauge reads
within the specified range, freeze the expansion valve
control head for 30 seconds using liquid CO
2or
another suitable super-cold material.Do not spray
R-134a or R-12 refrigerant on the expansion
valve control head for this test.The suction (low
pressure) gauge reading should drop by 10 psi. If OK,
go to Step 7 If not OK, replace the faulty expansion
valve.
(7) Allow the expansion valve control head to thaw.
The suction (low pressure) gauge reading should sta-
bilize at 140 kPa to 240 kPa (20 psi to 30 psi). If not
OK, replace the faulty expansion valve.
(8) When expansion valve testing is complete, test
the overall air conditioner performance. (Refer to 24 -
HEATING & AIR CONDITIONING - DIAGNOSIS
AND TESTING - A/C PERFORMANCE TEST).
Remove all test equipment before returning the vehi-
cle to service.
REMOVAL
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT - WARNING - A/C PLUMBING),
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT - CAUTION - A/C PLUMBING),
and (Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - FRONT - WARNING - HEATER PLUMB-
ING).
(1) Remove the rear heater-A/C unit housing from
the vehicle. (Refer to 24 - HEATING & AIR CONDI-
TIONING/DISTRIBUTION - REAR/REAR HEATER-
A/C HOUSING - REMOVAL).
(2) Carefully remove the foam insulator wrap from
the rear expansion valve.
(3) Remove the rear evaporator line extension from
the expansion valve. (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - REAR/EVAPORA-
TOR - REMOVAL - EVAPORATOR LINE EXTEN-
SION).
(4) Remove the two screws that secure the expan-
sion valve to the evaporator tube sealing plate.
(5) Remove the expansion valve from the evapora-
tor tubes.
(6) Remove the seals from the evaporator tube fit-
tings and discard.
(7) Install plugs in, or tape over the opened evap-
orator tube fittings and both expansion valve ports.
RSPLUMBING - REAR24-97
EXPANSION VALVE (Continued)
ProCarManuals.com

INSTALLATION
(1) Remove the tape or plugs from the evaporator
tube fittings and both expansion valve ports.
(2) Lubricate new rubber O-ring seals with clean
refrigerant oil and install them on the evaporator
tube fittings.
(3) Position the expansion valve onto the evapora-
tor tubes.
(4) Install and tighten the two screws that secure
the expansion valve to the evaporator tube sealing
plate. Tighten the screws to 11 N´m (97 in. lbs.).
(5) Reinstall the rear evaporator line extension
onto the expansion valve. (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - REAR/EVAPO-
RATOR - INSTALLATION - EVAPORATOR LINE
EXTENSION).
(6) Install the foam insulator wrap over the rear
expansion valve.
(7) Reinstall the rear heater-A/C unit housing into
the vehicle. (Refer to 24 - HEATING & AIR CONDI-
TIONING/DISTRIBUTION - REAR/REAR HEATER-
A/C HOUSING - INSTALLATION).
(8) Run the HVAC Cooldown Test to verify proper
operation.
HEATER CORE
DESCRIPTION
The rear heater core is located near the front of
the rear heater-A/C unit housing, behind the right
rear wheel house. It is a heat exchanger made of
rows of tubes and fins. One end of the core is fitted
with a molded plastic tank that includes integral
heater core inlet and outlet nipples. The heater core
can be serviced without removing the rear heater-A/C
unit housing from the vehicle. The heater core cannot
be repaired and, if faulty or damaged, it must be
replaced.
OPERATION
Engine coolant is circulated through heater hoses
to the heater core at all times. As the coolant flows
through the heater core, heat removed from the
engine is transferred to the heater core fins and
tubes. Air directed through the heater core picks up
the heat from the heater core fins. The blend air door
allows control of the heater output air temperature
by controlling how much of the air flowing through
the rear heater-A/C unit housing is directed through
the heater core.
STANDARD PROCEDURE - HEATER CORE
FILLING
In its final installed position, the rear heater core
is positioned higher than the radiator fill cap. There-fore, when the cooling system is drained and refilled,
gravity will not refill the heater core with coolant to
the proper level. This may result in two problems:1.
Insufficient coolant level in the engine cooling sys-
tem, which may result in engine overheating.2.Air
entrapped within the rear heater core, which may
result in insufficient rear heater performance. There
are two methods that may be employed to prevent
these problems:1.Pre-filling of the rear heater core.
2.Thermal cycling of the engine cooling system. Fol-
lowing are descriptions of both prevention methods,
as well as a method to verify rear heater perfor-
mance.
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING FRONT - WARNING - HEATER PLUMB-
ING).
PRE-FILLING
If the rear heater core or the rear heater-A/C hous-
ing have been removed from the vehicle for service,
the rear heater core may be pre-filled with the proper
engine coolant mixture prior to reconnecting the
heater hoses to the heater core hose fittings.
(1) The heater core should be installed in the rear
heater-A/C unit housing, and the rear heater-A/C
unit housing should be installed in the vehicle.
(2) Take the proper precautions to protect the car-
peting below the rear heater core from spilled engine
coolant and have absorbent toweling readily avail-
able to mop up any spills.
(3) Insert the small end of an appropriate funnel
into the upper hose fitting of the heater core (Fig. 4).
Fig. 4 Pre-Filling Heater Core - Typical
1 - REAR HEATER CORE
24 - 98 PLUMBING - REARRS
EXPANSION VALVE (Continued)
ProCarManuals.com

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
ProCarManuals.com

The following is a list of the monitored compo-
nents:
²Comprehensive Components
²Oxygen Sensor Monitor
²Oxygen Sensor Heater Monitor
²Catalyst Monitor
COMPREHENSIVE COMPONENTS
Along with the major monitors, OBD II requires
that the diagnostic system monitor any component
that could affect emissions levels. In many cases,
these components were being tested under OBD I.
The OBD I requirements focused mainly on testing
emissions-related components for electrical opens and
shorts.
However, OBD II also requires that inputs from
powertrain components to the PCM be tested for
rationality, and that outputs to powertrain compo-
nents from the PCM be tested forfunctionality.
Methods for monitoring the various Comprehensive
Component monitoring include:
(1) Circuit Continuity
²Open
²Shorted high
²Shorted to ground
(2) Rationality or Proper Functioning
²Inputs tested for rationality
²Outputs tested for functionality
NOTE: Comprehensive component monitors are
continuous. Therefore, enabling conditions do not
apply.
Input RationalityÐWhile input signals to the
PCM are constantly being monitored for electrical
opens and shorts, they are also tested for rationality.
This means that the input signal is compared against
other inputs and information to see if it makes sense
under the current conditions.
PCM sensor inputs that are checked for rationality
include:
²Manifold Absolute Pressure (MAP) Sensor
²Oxygen Sensor (O2S)
²Engine Coolant Temperature (ECT) Sensor
²Camshaft Position (CMP) Sensor
²Vehicle Speed Sensor
²Crankshaft Position (CKP) Sensor
²Intake/inlet Air Temperature (IAT) Sensor
²Throttle Position (TPS) Sensor
²Ambient Temperature Sensors
²Power Steering Switch
²Oxygen Sensor Heater
²Brake Switch
²Leak Detection Pump Switch or NVLD switch (if
equipped)
²P/N SwitchOutput FunctionalityÐPCM outputs are tested
for functionality in addition to testing for opens and
shorts. When the PCM provides a voltage to an out-
put component, it can verify that the command was
carried out by monitoring specific input signals for
expected changes. For example, when the PCM com-
mands the Idle Air Control (IAC) Motor to a specific
position under certain operating conditions, it expects
to see a specific (target) idle speed (RPM). If it does
not, it stores a DTC.
PCM outputs monitored for functionality include:
²Fuel Injectors
²Ignition Coils
²Idle Air Control
²Purge Solenoid
²EGR Solenoid (if equipped)
²LDP Solenoid or NVLD solenoid (if equipped)
²Radiator Fan Control
²Trans Controls
OXYGEN SENSOR (O2S) MONITOR
DESCRIPTIONÐEffective control of exhaust
emissions is achieved by an oxygen feedback system.
The most important element of the feedback system
is the O2S. The O2S is located in the exhaust path.
Once it reaches operating temperature 300É to 350ÉC
(572É to 662ÉF), the sensor generates a voltage that
is inversely proportional to the amount of oxygen in
the exhaust. When there is a large amount of oxygen
in the exhaust caused by a lean condition, the sensor
produces a low voltage, below 450 mV. When the oxy-
gen content is lower, caused by a rich condition, the
sensor produces a higher voltage, above 450mV (volt-
ages are offset by 2.5 volts on NGC vehicles).
The information obtained by the sensor is used to
calculate the fuel injector pulse width. The PCM is
programmed to maintain the optimum air/fuel ratio.
At this mixture ratio, the catalyst works best to
remove hydrocarbons (HC), carbon monoxide (CO)
and nitrous oxide (NOx) from the exhaust.
The O2S is also the main sensing element for the
EGR (if equipped), Catalyst and Fuel Monitors.
The O2S may fail in any or all of the following
manners:
²Slow response rate (Big Slope)
²Reduced output voltage (Half Cycle)
²Heater Performance
Slow Response Rate (Big Slope)ÐResponse rate
is the time required for the sensor to switch from
lean to rich signal output once it is exposed to a
richer than optimum A/F mixture or vice versa. As
the PCM adjusts the air/fuel ratio, the sensor must
be able to rapidly detect the change. As the sensor
ages, it could take longer to detect the changes in the
oxygen content of the exhaust gas. The rate of
change that an oxygen sensor experiences is called
25 - 2 EMISSIONS CONTROLRS
EMISSIONS CONTROL (Continued)
ProCarManuals.com

ªBig Slopeº. The PCM checks the oxygen sensor volt-
age in increments of a few milliseconds.
Reduced Output Voltage (Half Cycle)ÐThe
output voltage of the O2S ranges from 0 to 1 volt
(voltages are offset by 2.5 volts on NGC vehicles). A
good sensor can easily generate any output voltage in
this range as it is exposed to different concentrations
of oxygen. To detect a shift in the A/F mixture (lean
or rich), the output voltage has to change beyond a
threshold value. A malfunctioning sensor could have
difficulty changing beyond the threshold value. Each
time the voltage signal surpasses the threshold, a
counter is incremented by one. This is called the Half
Cycle Counter.
Heater PerformanceÐThe heater is tested by a
separate monitor. Refer to the Oxygen Sensor Heater
Monitor.
OPERATIONÐAs the Oxygen Sensor signal
switches, the PCM monitors the half cycle and big
slope signals from the oxygen sensor. If during the
test neither counter reaches a predetermined value, a
malfunction is entered and Freeze Frame data is
stored. Only one counter reaching its predetermined
value is needed for the monitor to pass.
The Oxygen Sensor Monitor is a two trip monitor
that is tested only once per trip. When the Oxygen
Sensor fails the test in two consecutive trips, the
MIL is illuminated and a DTC is set. The MIL is
extinguished when the Oxygen Sensor monitor
passes in three consecutive trips. The DTC is erased
from memory after 40 consecutive warm-up cycles
without test failure.
Enabling ConditionsÐThe following conditions
must typically be met for the PCM to run the oxygen
sensor monitor:
²Battery voltage
²Engine temperature
²Engine run time
²Engine run time at a predetermined speed
²Engine run time at a predetermined speed and
throttle opening
²Transmission in gear and brake depressed (auto-
matic only)
²Fuel system in Closed Loop
²Long Term Adaptive (within parameters)
²Power Steering Switch in low PSI (no load)
²Engine at idle
²Fuel level above 15%
²Ambient air temperature
²Barometric pressure
²Engine RPM within acceptable range of desired
idle
Pending ConditionsÐThe Task Manager typi-
cally does not run the Oxygen Sensor Monitor if over-
lapping monitors are running or the MIL is
illuminated for any of the following:²Misfire Monitor
²Front Oxygen Sensor and Heater Monitor
²MAP Sensor
²Vehicle Speed Sensor
²Engine Coolant Temperature Sensor
²Throttle Position Sensor
²Engine Controller Self Test Faults
²Cam or Crank Sensor
²Injector and Coil
²Idle Air Control Motor
²EVAP Electrical
²EGR Solenoid Electrical (if equipped)
²Intake/inlet Air Temperature
²5 Volt Feed
ConflictÐThe Task Manager does not run the
Oxygen Sensor Monitor if any of the following condi-
tions are present:
²A/C ON (A/C clutch cycling temporarily sus-
pends monitor)
²Purge flow in progress
²Ethanol content learn is taking place and the
ethanol used once flag is set (if equipped)
SuspendÐThe Task Manager suspends maturing
a fault for the Oxygen Sensor Monitor if any of the
following are present:
²Oxygen Sensor Heater Monitor, Priority 1
²Misfire Monitor, Priority 2
OXYGEN SENSOR HEATER MONITOR
DESCRIPTIONÐIf there is an oxygen sensor
(O2S) DTC as well as a O2S heater DTC, the O2S
fault MUST be repaired first. After the O2S fault is
repaired, verify that the heater circuit is operating
correctly.
The voltage readings taken from the O2S are very
temperature sensitive. The readings are not accurate
below a sensor temperature of 300ÉC. Heating of the
O2S is done to allow the engine controller to shift to
closed loop control as soon as possible. The heating
element used to heat the O2S must be tested to
ensure that it is heating the sensor properly.
The heater element itself is not tested. The sensor
output is used to test the heater by isolating the
effect of the heater element on the O2S output volt-
age from the other effects. The resistance is normally
between 100 ohms and 4.5 megaohms. When oxygen
sensor temperature increases, the resistance in the
internal circuit decreases. The PCM sends a 5 volts
biased signal through the oxygen sensors to ground
this monitoring circuit. As the temperature increases,
resistance decreases and the PCM detects a lower
voltage at the reference signal. Inversely, as the tem-
perature decreases, the resistance increases and the
PCM detects a higher voltage at the reference signal.
The O2S circuit is monitored for a drop in voltage.
RSEMISSIONS CONTROL25-3
EMISSIONS CONTROL (Continued)
ProCarManuals.com

period the switch ratio reaches a predetermined
value, a counter is incremented by one. The monitor
is enabled to run another test during that trip. When
the test fails 6 times, the counter increments to 3, a
malfunction is entered, and a Freeze Frame is stored,
the code is matured and the MIL is illuminated. If
the first test passes, no further testing is conducted
during that trip.
The MIL is extinguished after three consecutive
good trips. The good trip criteria for the catalyst
monitor is more stringent than the failure criteria. In
order to pass the test and increment one good trip,
the downstream sensor switch rate must be less than
45% of the upstream rate. The failure percentages
are 59% respectively.
Enabling ConditionsÐThe following conditions
must typically be met before the PCM runs the cat-
alyst monitor. Specific times for each parameter may
be different from engine to engine.
²Accumulated drive time
²Enable time
²Ambient air temperature
²Barometric pressure
²Catalyst warm-up counter
²Engine coolant temperature
²Vehicle speed
²MAP
²RPM
²Engine in closed loop
²Fuel level
Pending ConditionsÐ
²Misfire DTC
²Front Oxygen Sensor Response
²Front Oxygen Sensor Heater Monitor
²Front Oxygen Sensor Electrical
²Rear Oxygen Sensor Rationality (middle check)
²Rear Oxygen Sensor Heater Monitor
²Rear Oxygen Sensor Electrical
²Fuel System Monitor
²All TPS faults
²All MAP faults
²All ECT sensor faults
²Purge flow solenoid functionality
²Purge flow solenoid electrical
²All PCM self test faults
²All CMP and CKP sensor faults
²All injector and ignition electrical faults
²Idle Air Control (IAC) motor functionality
²Vehicle Speed Sensor
²Brake switch (auto trans only)
²Intake air temperature
ConflictÐThe catalyst monitor does not run if any
of the following are conditions are present:
²EGR Monitor in progress (if equipped)
²Fuel system rich intrusive test in progress
²EVAP Monitor in progress²Time since start is less than 60 seconds
²Low fuel level-less than 15 %
²Low ambient air temperature
²Ethanol content learn is taking place and the
ethanol used once flag is set
SuspendÐThe Task Manager does not mature a
catalyst fault if any of the following are present:
²Oxygen Sensor Monitor, Priority 1
²Oxygen Sensor Heater, Priority 1
²EGR Monitor, Priority 1 (if equipped)
²EVAP Monitor, Priority 1
²Fuel System Monitor, Priority 2
²Misfire Monitor, Priority 2
OPERATION - NON-MONITORED CIRCUITS
The PCM does not monitor all circuits, systems
and conditions that could have malfunctions causing
driveability problems. However, problems with these
systems may cause the PCM to store diagnostic trou-
ble codes for other systems or components. For exam-
ple, a fuel pressure problem will not register a fault
directly, but could cause a rich/lean condition or mis-
fire. This could cause the PCM to store an oxygen
sensor or misfire diagnostic trouble code.
The major non-monitored circuits are listed below
along with examples of failures modes that do not
directly cause the PCM to set a DTC, but for a sys-
tem that is monitored.
FUEL PRESSURE
The fuel pressure regulator controls fuel system
pressure. The PCM cannot detect a clogged fuel
pump inlet filter, clogged in-line fuel filter, or a
pinched fuel supply or return line. However, these
could result in a rich or lean condition causing the
PCM to store an oxygen sensor, fuel system, or mis-
fire diagnostic trouble code.
SECONDARY IGNITION CIRCUIT
The PCM cannot detect an inoperative ignition coil,
fouled or worn spark plugs, ignition cross firing, or
open spark plug cables. The misfire will however,
increase the oxygen content in the exhaust, deceiving
the PCM in to thinking the fuel system is too lean.
Also see misfire detection.
CYLINDER COMPRESSION
The PCM cannot detect uneven, low, or high engine
cylinder compression. Low compression lowers O2
content in the exhaust. Leading to fuel system, oxy-
gen sensor, or misfire detection fault.
EXHAUST SYSTEM
The PCM cannot detect a plugged, restricted or
leaking exhaust system. It may set a EGR (if
equipped) or Fuel system or O2S fault.
RSEMISSIONS CONTROL25-5
EMISSIONS CONTROL (Continued)
ProCarManuals.com

FUEL INJECTOR MECHANICAL MALFUNCTIONS
The PCM cannot determine if a fuel injector is
clogged, the needle is sticking or if the wrong injector
is installed. However, these could result in a rich or
lean condition causing the PCM to store a diagnostic
trouble code for either misfire, an oxygen sensor, or
the fuel system.
EXCESSIVE OIL CONSUMPTION
Although the PCM monitors engine exhaust oxygen
content when the system is in closed loop, it cannot
determine excessive oil consumption.
THROTTLE BODY AIR FLOW
The PCM cannot detect a clogged or restricted air
cleaner inlet or filter element.
VACUUM ASSIST
The PCM cannot detect leaks or restrictions in the
vacuum circuits of vacuum assisted engine control
system devices. However, these could cause the PCM
to store a MAP sensor diagnostic trouble code and
cause a high idle condition.
PCM SYSTEM GROUND
The PCM cannot determine a poor system ground.
However, one or more diagnostic trouble codes may
be generated as a result of this condition. The mod-
ule should be mounted to the body at all times,
including when diagnostics are performed.
PCM CONNECTOR ENGAGEMENT
The PCM may not be able to determine spread or
damaged connector pins. However, it might store
diagnostic trouble codes as a result of spread connec-
tor pins.
DESCRIPTION - MONITORED SYSTEMS
There are new electronic circuit monitors that
check fuel, emission, engine and ignition perfor-
mance. These monitors use information from various
sensor circuits to indicate the overall operation of the
fuel, engine, ignition and emission systems and thus
the emissions performance of the vehicle.
The fuel, engine, ignition and emission systems
monitors do not indicate a specific component prob-
lem. They do indicate that there is an implied prob-
lem within one of the systems and that a specific
problem must be diagnosed.
If any of these monitors detect a problem affecting
vehicle emissions, the Malfunction Indicator (Check
Engine) Lamp will be illuminated. These monitors
generate Diagnostic Trouble Codes that can be dis-
played with the a DRBIIItscan tool.
The following is a list of the system monitors:
²EGR Monitor (if equipped)²Misfire Monitor
²Fuel System Monitor
²Oxygen Sensor Monitor
²Oxygen Sensor Heater Monitor
²Catalyst Monitor
²Evaporative System Leak Detection Monitor (if
equipped)
Following is a description of each system monitor,
and its DTC.
Refer to the appropriate Powertrain Diagnos-
tics Procedures manual for diagnostic proce-
dures.
OXYGEN SENSOR (O2S) MONITOR
Effective control of exhaust emissions is achieved
by an oxygen feedback system. The most important
element of the feedback system is the O2S. The O2S
is located in the exhaust path. Once it reaches oper-
ating temperatures of 300É to 350ÉC (572É to 662ÉF),
the sensor generates a voltage that is inversely pro-
portional to the amount of oxygen in the exhaust.
The information obtained by the sensor is used to
calculate the fuel injector pulse width. The PCM is
programmed to maintain the optimum air/fuel ratio.
At this mixture ratio, the catalyst works best to
remove hydrocarbons (HC), carbon monoxide (CO)
and nitrous oxide (NOx) from the exhaust.
The O2S is also the main sensing element for the
EGR (if equipped), Catalyst and Fuel Monitors.
The O2S may fail in any or all of the following
manners:
²Slow response rate
²Reduced output voltage
²Dynamic shift
²Shorted or open circuits
Response rate is the time required for the sensor to
switch from lean to rich once it is exposed to a richer
than optimum A/F mixture or vice versa. As the sen-
sor starts malfunctioning, it could take longer to
detect the changes in the oxygen content of the
exhaust gas.
The output voltage of the O2S ranges from 0 to 1
volt (voltages are offset by 2.5 volts on NGC vehi-
cles). A good sensor can easily generate any output
voltage in this range as it is exposed to different con-
centrations of oxygen. To detect a shift in the A/F
mixture (lean or rich), the output voltage has to
change beyond a threshold value. A malfunctioning
sensor could have difficulty changing beyond the
threshold value.
OXYGEN SENSOR HEATER MONITOR
If there is an oxygen sensor (O2S) DTC as well as
a O2S heater DTC, the O2S heater fault MUST be
repaired first. After the O2S fault is repaired, verify
that the heater circuit is operating correctly.
25 - 6 EMISSIONS CONTROLRS
EMISSIONS CONTROL (Continued)
ProCarManuals.com

ABS FASTENER TORQUE,
SPECIFICATIONS......................5-79
ABSORBER - DESCRIPTION, SHOCK.......2-36
ABSORBER - INSTALLATION, SHOCK......2-38
ABSORBER - OPERATION, SHOCK........2-36
ABSORBER - REMOVAL, SHOCK..........2-36
ABSORBER (UPPER BUSHING) -
ASSEMBLY, SHOCK....................2-37
ABSORBER (UPPER BUSHING) -
DISASSEMBLY, SHOCK.................2-36
A/C COMPRESSOR - DESCRIPTION......24-63
A/C COMPRESSOR - OPERATION........24-63
A/C COOL DOWN TEST - DIAGNOSIS
AND TESTING........................24-4
A/C DISTRIBUTION DUCT -
INSTALLATION.......................24-53
A/C DISTRIBUTION DUCT - REMOVAL....24-53
A/C HEATER CONTROL - INSTALLATION....24-9
A/C HEATER CONTROL - REMOVAL.......24-9
A/C PERFORMANCE TEST - DIAGNOSIS
AND TESTING........................24-5
A/C PLUMBING - CAUTION.............24-61
A/C PLUMBING - WARNING............24-61
A/C PRESSURE TRANSDUCER -
DESCRIPTION.......................24-10
A/C PRESSURE TRANSDUCER -
DIAGNOSIS AND TESTING.............24-10
A/C PRESSURE TRANSDUCER -
INSTALLATION.......................24-11
A/C PRESSURE TRANSDUCER -
OPERATION.........................24-10
A/C PRESSURE TRANSDUCER -
REMOVAL..........................24-10
ACCELERATOR PEDAL - INSTALLATION . . . 14-24
ACCELERATOR PEDAL - REMOVAL.......14-23
ACCESSORY DRIVE BELT - DIAGNOSIS
AND TESTING.........................7-7
ACCESSORY DRIVE BELT TENSION,
SPECIFICATIONS.......................7-5
ACCESSORY RELAY - DESCRIPTION . . . 8W-97-2
ACCESSORY RELAY - DIAGNOSIS &
TESTING.........................8W-97-2
ACCESSORY RELAY - OPERATION.....8W-97-2
ACCUMULATOR - DESCRIPTION........21-188
ACCUMULATOR - OPERATION..........21-189
A/C-HEATER CONTROL - INSTALLATION . . . 24-29
A/C-HEATER CONTROL - REMOVAL......24-29
ACTUATOR - DESCRIPTION, BLEND
DOOR........................24-11,24-30
ACTUATOR - DESCRIPTION, ENGAGE.....8N-10
ACTUATOR - DESCRIPTION, LATCH......8N-14
ACTUATOR - DESCRIPTION, MODE
DOOR.............................24-24
ACTUATOR - DESCRIPTION,
RECIRCULATION DOOR................24-27
ACTUATOR - INSTALLATION, BLEND
DOOR........................24-12,24-31
ACTUATOR - INSTALLATION, ENGAGE....8N-11
ACTUATOR - INSTALLATION, LATCH.....8N-14
ACTUATOR - INSTALLATION, MODE
DOOR........................24-25,24-36
ACTUATOR - INSTALLATION,
RECIRCULATION DOOR................24-28
ACTUATOR - OPERATION, BLEND DOOR . . 24-11,
24-30
ACTUATOR - OPERATION, ENGAGE......8N-11
ACTUATOR - OPERATION, LATCH........8N-14
ACTUATOR - OPERATION, MODE DOOR . . . 24-24
ACTUATOR - OPERATION,
RECIRCULATION DOOR................24-27
ACTUATOR - REMOVAL, BLEND DOOR . . . 24-12,
24-31
ACTUATOR - REMOVAL, ENGAGE........8N-11
ACTUATOR - REMOVAL, LATCH.........8N-14
ACTUATOR - REMOVAL, MODE DOOR....24-25,
24-36
ACTUATOR - REMOVAL, RECIRCULATION
DOOR.............................24-27
ADAPTER - INSTALLATION, FRONT DISC
BRAKE CALIPER......................5-31
ADAPTER - INSTALLATION, OIL FILTER
. . . 9-139
ADAPTER - REMOVAL, FRONT DISC
BRAKE CALIPER
......................5-31
ADAPTER - REMOVAL, OIL FILTER
.......9-139
ADAPTIVE MEMORIES, OPERATION -
FUEL CORRECTION OR
................14-20
ADDING ADDITIONAL COOLANT -
STANDARD PROCEDURE
.................7-5ADDITIONAL COOLANT - STANDARD
PROCEDURE, ADDING...................7-5
ADHESIVE ATTACHED - INSTALLATION,
EXTERIOR NAME PLATES..............23-50
ADHESIVE ATTACHED - REMOVAL,
EXTERIOR NAME PLATES..............23-50
ADHESIVE LOCATIONS -
SPECIFICATIONS, STRUCTURAL........23-153
ADJUSTER-BORC-PILLAR -
INSTALLATION, SEAT BELT HEIGHT......8O-12
ADJUSTER-BORC-PILLAR -
REMOVAL, SEAT BELT HEIGHT..........8O-12
ADJUSTER - DIAGNOSIS AND TESTING,
DRUM BRAKE AUTOMATIC..............5-13
ADJUSTER - INSTALLATION, FRONT
SEAT TRACK MANUAL................23-94
ADJUSTER - INSTALLATION, FRONT
SEAT TRACK POWER.................23-94
ADJUSTER - REMOVAL, FRONT SEAT
TRACK MANUAL.....................23-94
ADJUSTER - REMOVAL, FRONT SEAT
TRACK POWER......................23-94
ADJUSTER KNOB - INSTALLATION, SEAT
BELT HEIGHT.......................8O-13
ADJUSTER KNOB - REMOVAL, SEAT
BELT HEIGHT.......................8O-13
ADJUSTER NOISE DIAGNOSIS -
DIAGNOSIS AND TESTING, HYDRAULIC
LASH...............................9-34
ADJUSTER TENSION RELEASE -
STANDARD PROCEDURE, PARKING
BRAKE AUTOMATIC....................5-58
ADJUSTER TENSION RESET -
STANDARD PROCEDURE, PARKING
BRAKE AUTOMATIC.....................5-59
ADJUSTERS - INSTALLATION,
HYDRAULIC LASH.....................9-34
ADJUSTERS - REMOVAL, HYDRAULIC
LASH...............................9-34
AERATION - DIAGNOSIS AND TESTING,
COOLING SYSTEM.....................7-3
AFTER AN AIRBAG DEPLOYMENT -
STANDARD PROCEDURE, SERVICE.......8O-3
AIR CLEANER ELEMENT - INSTALLATION . . 9-24,
9-98
AIR CLEANER ELEMENT - REMOVAL . . 9-24,9-98
AIR CLEANER HOUSING - INSTALLATION . . 9-24,
9-99
AIR CLEANER HOUSING - REMOVAL . . 9-24,9-99
AIR CONDITIONING LINES -
INSTALLATION, REAR................24-105
AIR CONDITIONING LINES - REMOVAL,
REAR.............................24-104
AIR CONTROL MOTOR - DESCRIPTION,
IDLE...............................14-28
AIR CONTROL MOTOR - INSTALLATION,
IDLE...............................14-29
AIR CONTROL MOTOR - OPERATION,
IDLE...............................14-28
AIR CONTROL MOTOR - REMOVAL, IDLE . . 14-29
AIR EXHAUSTER - DESCRIPTION, REAR
QUARTER PANEL/FENDER..............23-56
AIR EXHAUSTER - INSTALLATION, REAR
QUARTER PANEL/FENDER..............23-57
AIR EXHAUSTER - REMOVAL, REAR
QUARTER PANEL/FENDER..............23-56
AIR FILTER - DESCRIPTION............24-39
AIR FILTER - INSTALLATION............24-40
AIR FILTER - REMOVAL...............24-39
AIR GAP - STANDARD PROCEDURE,
COMPRESSOR CLUTCH...............24-17
AIR GAP, SPECIFICATIONS - WHEEL
SPEED SENSOR.......................5-79
AIR INTAKE PIPE - INSTALLATION......24-113
AIR INTAKE PIPE - REMOVAL..........24-112
AIR OUTLETS - DESCRIPTION.....24-40,24-52
AIR OUTLETS - INSTALLATION..........24-52
AIR OUTLETS - REMOVAL.............24-52
AIR PRESSURE TESTS - DIAGNOSIS
AND TESTING, CLUTCH...............21-122
AIR TEMPERATURE SENSOR -
DESCRIPTION, INLET.................14-29
AIR TEMPERATURE SENSOR -
OPERATION, INLET
...................14-29
AIRBAG - DESCRIPTION, DRIVER
........8O-5
AIRBAG - DESCRIPTION, PASSENGER
.....8O-7
AIRBAG - DESCRIPTION, SEAT
..........8O-10
AIRBAG - INSTALLATION, DRIVER
........8O-6AIRBAG - INSTALLATION, PASSENGER....8O-9
AIRBAG - OPERATION, DRIVER..........8O-5
AIRBAG - OPERATION, PASSENGER.......8O-8
AIRBAG - OPERATION, SEAT...........8O-11
AIRBAG - REMOVAL, DRIVER............8O-5
AIRBAG - REMOVAL, PASSENGER........8O-8
AIRBAG CONTROL MODULE -
DESCRIPTION, SIDE IMPACT...........8O-17
AIRBAG CONTROL MODULE -
INSTALLATION, SIDE IMPACT...........8O-17
AIRBAG CONTROL MODULE -
OPERATION, SIDE IMPACT.............8O-17
AIRBAG CONTROL MODULE - REMOVAL,
SIDE IMPACT.......................8O-17
AIRBAG DEPLOYMENT - STANDARD
PROCEDURE, SERVICE AFTER AN........8O-3
AIRBAG SYSTEM - DIAGNOSIS AND
TESTING............................8O-2
AIRBAG TRIM COVER - INSTALLATION,
DRIVER.............................8O-7
AIRBAG TRIM COVER - REMOVAL,
DRIVER.............................8O-6
AIRBAGS - STANDARD PROCEDURE,
HANDLING..........................8O-3
AJAR SWITCH - EXPORT -
INSTALLATION, HOOD.................8Q-3
AJAR SWITCH - EXPORT - REMOVAL,
HOOD..............................8Q-3
ALIGNMENT - DESCRIPTION, WHEEL......2-46
ALIGNMENT - EXPORT - STANDARD
PROCEDURE, FRONT FOG LAMP UNIT.....8L-9
ALIGNMENT - EXPORT - STANDARD
PROCEDURE, HEADLAMP UNIT.........8L-17
ALIGNMENT - STANDARD PROCEDURE,
FRONT FOG LAMP UNIT................8L-9
ALIGNMENT - STANDARD PROCEDURE,
FRONT WIPER ARM...................8R-8
ALIGNMENT - STANDARD PROCEDURE,
HEADLAMP UNIT.....................8L-17
ALIGNMENT - STANDARD PROCEDURE,
WHEEL.............................2-51
ALIGNMENT, SPECIFICATIONS - WHEEL....2-55
ALUMINUM WHEEL CARE - CLEANING . . . 22-18
AMBIENT TEMP SENSOR - DESCRIPTION . 8M-11
AMBIENT TEMP SENSOR - OPERATION . . 8M-11
AMBIENT TEMPERATURE SENSOR -
DIAGNOSIS AND TESTING.............8M-12
AMBIENT TEMPERATURE SENSOR
CIRCUIT - DIAGNOSIS AND TESTING....8M-12
AN AIRBAG DEPLOYMENT - STANDARD
PROCEDURE, SERVICE AFTER...........8O-3
ANTENNA - EXPORT - DESCRIPTION,
QUARTER GLASS INTEGRAL............8A-9
ANTENNA - EXPORT - DIAGNOSIS AND
TESTING, QUARTER GLASS INTEGRAL....8A-9
ANTENNA - EXPORT - OPERATION,
QUARTER GLASS INTEGRAL............8A-9
ANTENNA BODY AND CABLE -
DESCRIPTION........................8A-4
ANTENNA BODY AND CABLE -
DIAGNOSIS AND TESTING..............8A-4
ANTENNA BODY AND CABLE -
INSTALLATION.......................8A-6
ANTENNA BODY AND CABLE -
OPERATION..........................8A-4
ANTENNA BODY AND CABLE - REMOVAL . . 8A-5
ANTENNA CABLE - INSTALLATION,
INSTRUMENT PANEL..................8A-9
ANTENNA CABLE - REMOVAL,
INSTRUMENT PANEL..................8A-8
ANTENNA MODULE - EXPORT -
DESCRIPTION........................8A-6
ANTENNA MODULE - EXPORT -
DIAGNOSIS AND TESTING..............8A-7
ANTENNA MODULE - EXPORT -
INSTALLATION.......................8A-7
ANTENNA MODULE - EXPORT -
OPERATION..........................8A-6
ANTENNA MODULE - EXPORT -
REMOVAL
...........................8A-7
ANTILOCK BRAKE - DESCRIPTION,
CONTROLLER
........................8E-5
ANTILOCK BRAKE - INSTALLATION,
CONTROLLER
........................8E-6
ANTILOCK BRAKE - OPERATION,
CONTROLLER
........................8E-5
ANTILOCK BRAKE - REMOVAL,
CONTROLLER
........................8E-6
RSINDEX1
Description Group-Page Description Group-Page Description Group-Page
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