control arm DODGE RAM 2001 Service Repair Manual

INSTALLATION
NOTE: Before installing the blend door actuator, be
certain that the blend door is not binding and is
capable of full travel in both directions.
(1) Align the actuator with the blend door shaft
and rotate the actuator to align it to the mounting
bosses on the HVAC housing.
(2) Align and install the actuator screws. Tighten
the mounting screws to 2.2 N´m (20 in. lbs.).
(3) Plug in the wire harness connector to the blend
door actuator.
(4) Install the HVAC housing in the vehicle. (Refer
to 24 - HEATING & AIR CONDITIONING/DISTRI-
BUTION/HVAC HOUSING - INSTALLATION)
(5) Install the instrument panel in the vehicle.
Refer to Instrument Panel System for the procedures.
(6) Make sure the Temperature Control Knob is in
the mid (12 o'clock) position to allow the actuator to
automatically position itself in the mid position and
come to a complete stop when powered up.
(7) Connect the battery negative cable.
MODE DOOR ACTUATOR
REMOVAL - HEAT/DEFROST DOOR ACTUATOR
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the HVAC housing from the vehicle
and place it on a work bench. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION/HVAC
HOUSING - REMOVAL)
(3) Unplug the two vacuum harness connectors
from the heat/defrost door actuator (Fig. 25).
(4) Using a trim stick or another suitable wide
flat-bladed tool, gently pry the heat/defrost door
crank arm off the heat/defrost door pivot.
(5) Remove the two screws that secure the heat/de-
frost door actuator to the HVAC housing.
(6) Remove the heat/defrost door actuator from the
HVAC housing.
Fig. 24 BLEND DOOR ACTUATOR REMOVE/
INSTALL
1 - DUCT
2 - MOUNTING SCREWS
3 - UNIT HOUSING
4 - HARNESS AND CONNECTOR
5 - BLEND DOOR ACTUATOR
Fig. 25 HEAT/DEFROST DOOR ACTUATOR
1 - VACUUM LINE
2 - DOOR PIVOT CONNECTION
3 - HEAT/DEFROST DOOR ACTUATOR
24 - 26 CONTROLSBR/BE
BLEND DOOR ACTUATOR (Continued)

REMOVAL - PANEL/DEFROST DOOR
ACTUATOR
WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS,
DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPT-
ING ANY STEERING WHEEL, STEERING COLUMN, OR
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. DISCONNECT AND ISOLATE THE BATTERY
NEGATIVE (GROUND) CABLE, THEN WAIT TWO MIN-
UTES FOR THE AIRBAG SYSTEM CAPACITOR TO DIS-
CHARGE BEFORE PERFORMING FURTHER
DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE
WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO
TAKE THE PROPER PRECAUTIONS COULD RESULT
IN AN ACCIDENTAL AIRBAG DEPLOYMENT AND POS-
SIBLE PERSONAL INJURY.
(1)Disconnect and isolate the battery negative cable.
(2) Remove the instrument panel assembly from
the vehicle. Refer to Instrument Panel System for the
procedures.
(3) Unplug the vacuum harness connector from the
panel/defrost door actuator (Fig. 26).
(4) Using a trim stick or another suitable wide
flat-bladed tool, gently pry the panel/defrost door
crank arm off the panel/defrost door pivot.
(5) Remove the two screws that secure the panel/
defrost door actuator to the HVAC housing.
(6) Remove the panel/defrost door actuator from
the HVAC housing.
INSTALLATION - HEAT/DEFROST DOOR
ACTUATOR
NOTE: Before installing the heat/defrost door actuator,
be certain that the heat/defrost door is not binding.
(1) Install the heat/defrost door actuator from the
HVAC housing. Tighten the actuator mounting
screws to 2.2 N´m (20 in. lbs.).
(2) Carefully snap the heat/defrost door crank arm
on the heat/defrost door pivot.
(3) Plug in the two vacuum harness connectors to
the heat/defrost door actuator.
(4) Install the HVAC housing in the vehicle. (Refer
to 24 - HEATING & AIR CONDITIONING/DISTRI-
BUTION/HVAC HOUSING - INSTALLATION)
(5) Connect the battery negative cable.
INSTALLATION - PANEL/DEFROST DOOR
ACTUATOR
NOTE: Before installing the panel/defrost door actuator,
be certain that the panel/defrost door is not binding.
(1) Install the panel/defrost door actuator on the
HVAC housing. Tighten the mounting screws to 2.2
N´m (20 in. lbs.).
(2) Carefully snap the panel/defrost door crank
arm on the panel/defrost door pivot.
(3) Plug the vacuum harness connector to the pan-
el/defrost door actuator.
(4) Install the instrument panel assembly in the
vehicle. Refer to Instrument Panel System for the
procedures.
(5) Connect the battery negative cable.
RECIRCULATION DOOR
ACTUATOR
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
Fig. 26 PANEL/DEFROST DOOR ACTUATOR
1 - VACUUM LINE
2 - PANEL/DEFROST ACTUATOR
3 - SHAFT RETAINER
BR/BECONTROLS 24 - 27
MODE DOOR ACTUATOR (Continued)

REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the wiper arms from the wiper pivots.
Refer to Wipers/Washers for the procedures.
(3) Remove the weatherstrip along the front edge
of the cowl plenum cover/grille panel and the cowl
plenum panel (Fig. 30).
(4) Remove the plastic screws that secure the cowl
plenum cover/grille panel to the studs on the cowl top
panel near the base of the windshield (Fig. 31).(5) Lift the cowl plenum cover/grille panel from the
cowl top far enough to access the vacuum reservoir
near the right end of the cowl plenum.
(6) Disconnect the vacuum supply hose from the
vacuum reservoir, which is secured to the dash panel
near the right end of the cowl plenum (Fig. 32).
(7) Remove the two nuts that secure the reservoir
to the studs on the dash panel near the right end of
the cowl plenum.
(8) Remove the vacuum reservoir from the dash
panel studs.
INSTALLATION
(1) Install the vacuum reservoir on the dash panel
studs. Tighten the mounting nuts to 2.8 N´m (25 in.
lbs.).
(2) Connect the vacuum supply hose to the vac-
uum reservoir.
(3) Install the plastic screws that secure the cowl
plenum cover/grille panel to the studs on the cowl top
panel.
(4) Install the weatherstrip along the front edge of
the cowl plenum cover/grille panel and the cowl ple-
num panel.
(5) Install the wiper arms on the wiper pivots.
Refer to Wipers/Washers for the procedures.
(6) Connect the battery negative cable.
Fig. 30 COWL PLENUM COVER/GRILLE PANEL
WEATHERSTRIP
1 - COWL GRILLE
2 - WEATHERSTRIP
Fig. 31 COWL PLENUM PLASTIC SCREWS
REMOVAL
1 - PLASTIC SCREW ANCHOR
2 - COWL GRILLE
Fig. 32 VACUUM RESERVOIR REMOVE/INSTALL
1 - COWL PLENUM
2 - VACUUM RESERVOIR
24 - 30 CONTROLSBR/BE
VACUUM RESERVOIR (Continued)

DISTRIBUTION
TABLE OF CONTENTS
page page
DISTRIBUTION
DESCRIPTION...........................31
AIR OUTLETS
REMOVAL..............................31
INSTALLATION...........................32
BLOWER MOTOR
DESCRIPTION...........................32
OPERATION.............................32
DIAGNOSIS AND TESTING.................33
BLOWER MOTOR......................33
REMOVAL..............................33
INSTALLATION...........................33
DEFROSTER DUCTS
REMOVAL..............................34
INSTALLATION...........................35
HVAC HOUSING
REMOVAL..............................35DISASSEMBLY...........................36
ASSEMBLY.............................36
INSTALLATION...........................37
INSTRUMENT PANEL DEMISTER DUCTS
REMOVAL..............................37
INSTRUMENT PANEL DUCTS
REMOVAL..............................37
BLEND DOOR
REMOVAL..............................38
INSTALLATION...........................38
MODE DOOR
REMOVAL..............................38
INSTALLATION...........................39
RECIRCULATION DOOR
REMOVAL..............................39
INSTALLATION...........................39
DISTRIBUTION
DESCRIPTION - HVAC SYSTEM AIRFLOW
Outside air enters the vehicle through the cowl top
opening at the base of the windshield, and passes
through a plenum chamber to the HVAC system blower
housing (Fig. 1). Air flow velocity can then be adjusted
with the blower motor switch on the a/c heater control
panel. The air intake openings must be kept free of
snow, ice, leaves, and other obstructions for the HVAC
system to receive a sufficient volume of outside air.
It is also important to keep the air intake openings
clear of debris because leaf particles and other debris
that is small enough to pass through the cowl plenum
screen can accumulate within the HVAC housing. The
closed, warm, damp and dark environment created
within the HVAC housing is ideal for the growth of cer-
tain molds, mildews and other fungi. Any accumulation
of decaying plant matter provides an additional food
source for fungal spores, which enter the housing with
the fresh air. Excess debris, as well as objectionable
odors created by decaying plant matter and growing
fungi can be discharged into the passenger compart-
ment during HVAC system operation.
AIR OUTLETS
REMOVAL - DEMISTER GRILLES
(1) Using a trim stick or another suitable wide
flat-bladed tool, gently pry at the perimeter edges ofthe demister grille to release the snap features from
the instrument panel top cover.
(2) Remove the demister grille from the instru-
ment panel.
Fig. 1 HVAC SYSTEM AIRFLOW
1 - DEFROST OUTLET
2 - OUTSIDE AIR INLET
3 - RECIRCULATION INLET
4 - FLOOR OUTLET
5 - PANEL OUTLET
BR/BEDISTRIBUTION 24 - 31

After passing the leak detection phase of the test,
system pressure is maintained by turning on the
LDP's solenoid until the purge system is activated.
Purge activation in effect creates a leak. The cycle
rate is again interrogated and when it increases due
to the flow through the purge system, the leak check
portion of the diagnostic is complete.
The canister vent valve will unseal the system
after completion of the test sequence as the pump
diaphragm assembly moves to the full travel position.
Evaporative system functionality will be verified by
using the stricter evap purge flow monitor. At an
appropriate warm idle the LDP will be energized to
seal the canister vent. The purge flow will be clocked
up from some small value in an attempt to see a
shift in the 02 control system. If fuel vapor, indicated
by a shift in the 02 control, is present the test is
passed. If not, it is assumed that the purge system is
not functioning in some respect. The LDP is again
turned off and the test is ended.
MISFIRE MONITOR
Excessive engine misfire results in increased cata-
lyst temperature and causes an increase in HC emis-
sions. Severe misfires could cause catalyst damage.
To prevent catalytic convertor damage, the PCM
monitors engine misfire.
The Powertrain Control Module (PCM) monitors
for misfire during most engine operating conditions
(positive torque) by looking at changes in the crank-
shaft speed. If a misfire occurs the speed of the
crankshaft will vary more than normal.
FUEL SYSTEM MONITOR
To comply with clean air regulations, vehicles are
equipped with catalytic converters. These converters
reduce the emission of hydrocarbons, oxides of nitro-
gen and carbon monoxide. The catalyst works best
when the Air Fuel (A/F) ratio is at or near the opti-
mum of 14.7 to 1.
The PCM is programmed to maintain the optimum
air/fuel ratio of 14.7 to 1. This is done by making
short term corrections in the fuel injector pulse width
based on the O2S sensor output. The programmed
memory acts as a self calibration tool that the engine
controller uses to compensate for variations in engine
specifications, sensor tolerances and engine fatigue
over the life span of the engine. By monitoring the
actual fuel-air ratio with the O2S sensor (short term)
and multiplying that with the program long-term
(adaptive) memory and comparing that to the limit,
it can be determined whether it will pass an emis-
sions test. If a malfunction occurs such that the PCM
cannot maintain the optimum A/F ratio, then the
MIL will be illuminated.
CATALYST MONITOR
To comply with clean air regulations, vehicles are
equipped with catalytic converters. These converters
reduce the emission of hydrocarbons, oxides of nitro-
gen and carbon monoxide.
Normal vehicle miles or engine misfire can cause a
catalyst to decay. A meltdown of the ceramic core can
cause a reduction of the exhaust passage. This can
increase vehicle emissions and deteriorate engine
performance, driveability and fuel economy.
The catalyst monitor uses dual oxygen sensors
(O2S's) to monitor the efficiency of the converter. The
dual O2S's sensor strategy is based on the fact that
as a catalyst deteriorates, its oxygen storage capacity
and its efficiency are both reduced. By monitoring
the oxygen storage capacity of a catalyst, its effi-
ciency can be indirectly calculated. The upstream
O2S is used to detect the amount of oxygen in the
exhaust gas before the gas enters the catalytic con-
verter. The PCM calculates the A/F mixture from the
output of the O2S. A low voltage indicates high oxy-
gen content (lean mixture). A high voltage indicates a
low content of oxygen (rich mixture).
When the upstream O2S detects a lean condition,
there is an abundance of oxygen in the exhaust gas.
A functioning converter would store this oxygen so it
can use it for the oxidation of HC and CO. As the
converter absorbs the oxygen, there will be a lack of
oxygen downstream of the converter. The output of
the downstream O2S will indicate limited activity in
this condition.
As the converter loses the ability to store oxygen,
the condition can be detected from the behavior of
the downstream O2S. When the efficiency drops, no
chemical reaction takes place. This means the con-
centration of oxygen will be the same downstream as
upstream. The output voltage of the downstream
O2S copies the voltage of the upstream sensor. The
only difference is a time lag (seen by the PCM)
between the switching of the O2S's.
To monitor the system, the number of lean-to-rich
switches of upstream and downstream O2S's is
counted. The ratio of downstream switches to
upstream switches is used to determine whether the
catalyst is operating properly. An effective catalyst
will have fewer downstream switches than it has
upstream switches i.e., a ratio closer to zero. For a
totally ineffective catalyst, this ratio will be one-to-
one, indicating that no oxidation occurs in the device.
The system must be monitored so that when cata-
lyst efficiency deteriorates and exhaust emissions
increase to over the legal limit, the MIL will be illu-
minated.
BR/BEEMISSIONS CONTROL 25 - 17
EMISSIONS CONTROL (Continued)

DESCRIPTION - TRIP DEFINITION
The term ªTripº has different meanings depending
on what the circumstances are. If the MIL (Malfunc-
tion Indicator Lamp) is OFF, a Trip is defined as
when the Oxygen Sensor Monitor and the Catalyst
Monitor have been completed in the same drive cycle.
When any Emission DTC is set, the MIL on the
dash is turned ON. When the MIL is ON, it takes 3
good trips to turn the MIL OFF. In this case, it
depends on what type of DTC is set to know what a
ªTripº is.
For the Fuel Monitor or Mis-Fire Monitor (contin-
uous monitor), the vehicle must be operated in the
ªSimilar Condition Windowº for a specified amount of
time to be considered a Good Trip.
If a Non-Contiuous OBDII Monitor fails twice in a
row and turns ON the MIL, re-running that monitor
which previously failed, on the next start-up and
passing the monitor, is considered to be a Good Trip.
These will include the following:
²Oxygen Sensor
²Catalyst Monitor
²Purge Flow Monitor
²Leak Detection Pump Monitor (if equipped)
²EGR Monitor (if equipped)
²Oxygen Sensor Heater Monitor
If any other Emission DTC is set (not an OBDII
Monitor), a Good Trip is considered to be when the
Oxygen Sensor Monitor and Catalyst Monitor have
been completed; or 2 Minutes of engine run time if
the Oxygen Sensor Monitor or Catalyst Monitor have
been stopped from running.
It can take up to 2 Failures in a row to turn on the
MIL. After the MIL is ON, it takes 3 Good Trips to
turn the MIL OFF. After the MIL is OFF, the PCM
will self-erase the DTC after 40 Warm-up cycles. A
Warm-up cycle is counted when the ECT (Engine
Coolant Temperature Sensor) has crossed 160ÉF and
has risen by at least 40ÉF since the engine has been
started.
DESCRIPTION - COMPONENT MONITORS -
GAS ENGINES
There are several components that will affect vehi-
cle emissions if they malfunction. If one of these com-
ponents malfunctions the Malfunction Indicator
Lamp (MIL) will illuminate.
Some of the component monitors are checking for
proper operation of the part. Electrically operated
components now have input (rationality) and output
(functionality) checks. Previously, a component like
the Throttle Position sensor (TPS) was checked by
the PCM for an open or shorted circuit. If one of
these conditions occurred, a DTC was set. Now there
is a check to ensure that the component is working.
This is done by watching for a TPS indication of agreater or lesser throttle opening than MAP and
engine rpm indicate. In the case of the TPS, if engine
vacuum is high and engine rpm is 1600 or greater,
and the TPS indicates a large throttle opening, a
DTC will be set. The same applies to low vacuum if
the TPS indicates a small throttle opening.
All open/short circuit checks, or any component
that has an associated limp-in, will set a fault after 1
trip with the malfunction present. Components with-
out an associated limp-in will take two trips to illu-
minate the MIL.
DESCRIPTION - COMPONENT MONITORS -
DIESEL ENGINES
There are several electrical components that will
affect vehicle emissions if they malfunction. If one of
these components is malfunctioning, a Diagnostic
Trouble Code (DTC) will be set by either the Power-
train Control Module (PCM) or the Engine Control
Module (ECM). The Malfunction Indicator Lamp
(MIL) will then be illuminated when the engine is
running.
These electrically operated components have input
(rationality) and output (functionality) checks. A
check is done by one or more components to check
the operation of another component.
Example:The Intake Manifold Air Temperature
(IAT) sensor is used to monitor intake manifold air
temperature over a period of time after a cold start.
If the temperature has not risen to a certain specifi-
cation during a specified time, a Diagnostic Trouble
Code (DTC) will be set for a problem in the manifold
air heater system.
All open/short circuit checks, or any component
that has an associated limp-in will set a DTC and
trigger the MIL after 1 trip with the malfunction
present. Components without an associated limp-in
will take two trips to illuminate the MIL.
OPERATION - GAS ENGINES
The Powertrain Control Module (PCM) monitors
many different circuits in the fuel injection, ignition,
emission and engine systems. If the PCM senses a
problem with a monitored circuit often enough to
indicate an actual problem, it stores a Diagnostic
Trouble Code (DTC) in the PCM's memory. If the
problem is repaired or ceases to exist, the PCM can-
cels the code after 40 warm-up cycles. Diagnostic
trouble codes that affect vehicle emissions illuminate
the Malfunction Indicator Lamp (MIL). The MIL is
displayed as an engine icon (graphic) on the instru-
ment panel. Refer to Malfunction Indicator Lamp in
this section.
Certain criteria must be met before the PCM
stores a DTC in memory. The criteria may be a spe-
25 - 18 EMISSIONS CONTROLBR/BE
EMISSIONS CONTROL (Continued)

cific range of engine RPM, engine temperature,
and/or input voltage to the PCM.
The PCM might not store a DTC for a monitored
circuit even though a malfunction has occurred. This
may happen because one of the DTC criteria for the
circuit has not been met.For example, assume the
diagnostic trouble code criteria requires the PCM to
monitor the circuit only when the engine operates
between 750 and 2000 RPM. Suppose the sensor's
output circuit shorts to ground when engine operates
above 2400 RPM (resulting in 0 volt input to the
PCM). Because the condition happens at an engine
speed above the maximum threshold (2000 rpm), the
PCM will not store a DTC.
There are several operating conditions for which
the PCM monitors and sets DTC's. Refer to Moni-
tored Systems, Components, and Non-Monitored Cir-
cuits in this section.
Technicians must retrieve stored DTC's by connect-
ing the DRB scan tool (or an equivalent scan tool) to
the 16±way data link connector (Fig. 3).
NOTE: Various diagnostic procedures may actually
cause a diagnostic monitor to set a DTC. For
instance, pulling a spark plug wire to perform a
spark test may set the misfire code. When a repair
is completed and verified, connect the DRB scan
tool to the 16±way data link connector to erase all
DTC's and extinguish the MIL.
OPERATION - DIESEL
The PCM and ECM monitor many different cir-
cuits in the powertrain system. If the ECM or PCM
senses a problem with a monitored circuit oftenenough to indicate an actual problem, it stores a
Diagnostic Trouble Code (DTC) in the ECM's or
PCM's memory. With certain DTC's, if the problem is
repaired or ceases to exist, the ECM or PCM cancels
the code after 40 warm-up cycles. Certain other
DTC's may be cancelled after 1 or 2 good ªtripsº.
Refer to Trip Definition. DTC's that affect vehicle
emissions illuminate the Malfunction Indicator Lamp
(MIL). The MIL is displayed as an engine icon
(graphic) on the instrument panel. Refer to Malfunc-
tion Indicator Lamp.
Certain DTC's will set a ªcompanion DTCº in the
opposite control module. This means that after
repair, the DTC must be erased frombothmodules.
Certain criteria must be met before the ECM or
PCM will store a DTC in memory. The criteria may
be a specific range of engine RPM, throttle opening,
engine temperature or input voltage.
The ECM or PCM might not store a DTC for a
monitored circuit even though a malfunction has
occurred. This may happen because one of the DTC
criteria for the circuit has not been met.For exam-
ple,assume the DTC criteria requires the ECM to
monitor the circuit only when the engine operates
between 750 and 2000 RPM. Suppose the sensor's
output circuit shorts to ground when engine operates
above 2400 RPM (resulting in 0 volt input to the
ECM). Because the condition happens at an engine
speed above the maximum threshold (2000 rpm), the
ECM will not store a DTC.
There are several operating conditions for which
the ECM and PCM monitors and sets DTC's. Refer to
Monitored Systems, Components, and Non-Monitored
Circuits.
Technicians must retrieve stored DTC's by connect-
ing the DRB scan tool (or an equivalent scan tool) to
the 16±way data link connector (Fig. 3). Refer to the
Diagnostic Trouble Code chart (list).Remember
that DTC's are the results of a system or circuit
failure, but do not directly identify the failed
component or components.
Various diagnostic procedures may actually cause a
diagnostic monitor to set a DTC. For instance, dis-
connecting a relay or removing an electrical connec-
tor while the engine is running. When a repair is
completed and verified, connect the DRB scan tool to
the 16±way data link connector to erase all ECM and
PCM DTC's and extinguish the MIL.
OPERATION - TASK MANAGER
The Task Manager determines which tests happen
when and which functions occur when. Many of the
diagnostic steps required by OBD II must be per-
formed under specific operating conditions. The Task
Manager software organizes and prioritizes the diag-
nostic procedures. The job of the Task Manager is to
Fig. 3 16-WAY DATA LINK CONNECTOR
1 - DATA LINK CONNECTOR
BR/BEEMISSIONS CONTROL 25 - 19
EMISSIONS CONTROL (Continued)

DTC Self Erasure
With one trip components or systems, the MIL is
illuminated upon test failure and DTCs are stored.
Two trip monitors are components requiring failure
in two consecutive trips for MIL illumination. Upon
failure of the first test, the Task Manager enters a
maturing code. If the component fails the test for a
second time the code matures and a DTC is set.
After three good trips the MIL is extinguished and
the Task Manager automatically switches the trip
counter to a warm-up cycle counter. DTCs are auto-
matically erased following 40 warm-up cycles if the
component does not fail again.
For misfire and fuel system monitors, the compo-
nent must pass the test under a Similar Conditions
Window in order to record a good trip. A Similar Con-
ditions Window is when engine RPM is within6375
RPM and load is within610% of when the fault
occurred.
NOTE: It is important to understand that a compo-
nent does not have to fail under a similar window of
operation to mature. It must pass the test under a
Similar Conditions Window when it failed to record
a Good Trip for DTC erasure for misfire and fuel
system monitors.
DTCs can be erased anytime with a DRB III. Eras-
ing the DTC with the DRB III erases all OBD II
information. The DRB III automatically displays a
warning that erasing the DTC will also erase all
OBD II monitor data. This includes all counter infor-
mation for warm-up cycles, trips and Freeze Frame.
Trip Indicator
TheTripis essential for running monitors and
extinguishing the MIL. In OBD II terms, a trip is a
set of vehicle operating conditions that must be met
for a specific monitor to run. All trips begin with a
key cycle.
Good Trip
The Good Trip counters are as follows:
²Specific Good Trip
²Fuel System Good Trip
²Misfire Good Trip
²Alternate Good Trip (appears as a Global Good
Trip on DRB III)
²Comprehensive Components
²Major Monitor
²Warm-Up Cycles
Specific Good Trip
The term Good Trip has different meanings
depending on the circumstances:
²If the MIL is OFF, a trip is defined as when the
Oxygen Sensor Monitor and the Catalyst Monitor
have been completed in the same drive cycle.²If the MIL is ON and a DTC was set by the Fuel
Monitor or Misfire Monitor (both continuous moni-
tors), the vehicle must be operated in the Similar
Condition Window for a specified amount of time.
²If the MIL is ON and a DTC was set by a Task
Manager commanded once-per-trip monitor (such as
the Oxygen Sensor Monitor, Catalyst Monitor, Purge
Flow Monitor, Leak Detection Pump Monitor, EGR
Monitor or Oxygen Sensor Heater Monitor), a good
trip is when the monitor is passed on the next start-
up.
²If the MIL is ON and any other emissions DTC
was set (not an OBD II monitor), a good trip occurs
when the Oxygen Sensor Monitor and Catalyst Mon-
itor have been completed, or two minutes of engine
run time if the Oxygen Sensor Monitor and Catalyst
Monitor have been stopped from running.
Fuel System Good Trip
To count a good trip (three required) and turn off
the MIL, the following conditions must occur:
²Engine in closed loop
²Operating in Similar Conditions Window
²Short Term multiplied by Long Term less than
threshold
²Less than threshold for a predetermined time
If all of the previous criteria are met, the PCM will
count a good trip (three required) and turn off the
MIL.
Misfire Good Trip
If the following conditions are met the PCM will
count one good trip (three required) in order to turn
off the MIL:
²Operating in Similar Condition Window
²1000 engine revolutions with no misfire
Warm-Up Cycles
Once the MIL has been extinguished by the Good
Trip Counter, the PCM automatically switches to a
Warm-Up Cycle Counter that can be viewed on the
DRB III. Warm-Up Cycles are used to erase DTCs
and Freeze Frames. Forty Warm-Up cycles must
occur in order for the PCM to self-erase a DTC and
Freeze Frame. A Warm-Up Cycle is defined as fol-
lows:
²Engine coolant temperature must start below
and rise above 160É F
²Engine coolant temperature must rise by 40É F
²No further faults occur
Freeze Frame Data Storage
Once a failure occurs, the Task Manager records
several engine operating conditions and stores it in a
Freeze Frame. The Freeze Frame is considered one
frame of information taken by an on-board data
recorder. When a fault occurs, the PCM stores the
input data from various sensors so that technicians
BR/BEEMISSIONS CONTROL 25 - 21
EMISSIONS CONTROL (Continued)

can determine under what vehicle operating condi-
tions the failure occurred.
The data stored in Freeze Frame is usually
recorded when a system fails the first time for two
trip faults. Freeze Frame data will only be overwrit-
ten by a different fault with a higher priority.
CAUTION: Erasing DTCs, either with the DRB III or
by disconnecting the battery, also clears all Freeze
Frame data.
Similar Conditions Window
The Similar Conditions Window displays informa-
tion about engine operation during a monitor. Abso-
lute MAP (engine load) and Engine RPM are stored
in this window when a failure occurs. There are two
different Similar conditions Windows: Fuel System
and Misfire.
FUEL SYSTEM
²Fuel System Similar Conditions WindowÐ
An indicator that 'Absolute MAP When Fuel Sys Fail'
and 'RPM When Fuel Sys Failed' are all in the same
range when the failure occurred. Indicated by switch-
ing from 'NO' to 'YES'.
²Absolute MAP When Fuel Sys FailÐ The
stored MAP reading at the time of failure. Informs
the user at what engine load the failure occurred.
²Absolute MAPÐ A live reading of engine load
to aid the user in accessing the Similar Conditions
Window.
²RPM When Fuel Sys FailÐ The stored RPM
reading at the time of failure. Informs the user at
what engine RPM the failure occurred.
²Engine RPMÐ A live reading of engine RPM
to aid the user in accessing the Similar Conditions
Window.
²Adaptive Memory FactorÐ The PCM utilizes
both Short Term Compensation and Long Term Adap-
tive to calculate the Adaptive Memory Factor for
total fuel correction.
²Upstream O2S VoltsÐ A live reading of the
Oxygen Sensor to indicate its performance. For
example, stuck lean, stuck rich, etc.
²SCW Time in Window (Similar Conditions
Window Time in Window)Ð A timer used by the
PCM that indicates that, after all Similar Conditions
have been met, if there has been enough good engine
running time in the SCW without failure detected.
This timer is used to increment a Good Trip.
²Fuel System Good Trip CounterÐATrip
Counter used to turn OFF the MIL for Fuel System
DTCs. To increment a Fuel System Good Trip, the
engine must be in the Similar Conditions Window,
Adaptive Memory Factor must be less than cali-
brated threshold and the Adaptive Memory Factormust stay below that threshold for a calibrated
amount of time.
²Test Done This TripÐ Indicates that the
monitor has already been run and completed during
the current trip.
MISFIRE
²Same Misfire Warm-Up StateÐ Indicates if
the misfire occurred when the engine was warmed up
(above 160É F).
²In Similar Misfire WindowÐ An indicator
that 'Absolute MAP When Misfire Occurred' and
'RPM When Misfire Occurred' are all in the same
range when the failure occurred. Indicated by switch-
ing from 'NO' to 'YES'.
²Absolute MAP When Misfire OccurredÐ
The stored MAP reading at the time of failure.
Informs the user at what engine load the failure
occurred.
²Absolute MAPÐ A live reading of engine load
to aid the user in accessing the Similar Conditions
Window.
²RPM When Misfire OccurredÐ The stored
RPM reading at the time of failure. Informs the user
at what engine RPM the failure occurred.
²Engine RPMÐ A live reading of engine RPM
to aid the user in accessing the Similar Conditions
Window.
²Adaptive Memory FactorÐ The PCM utilizes
both Short Term Compensation and Long Term Adap-
tive to calculate the Adaptive Memory Factor for
total fuel correction.
²200 Rev CounterÐ Counts 0±100 720 degree
cycles.
²SCW Cat 200 Rev CounterÐ Counts when in
similar conditions.
²SCW FTP 1000 Rev CounterÐ Counts 0±4
when in similar conditions.
²Misfire Good Trip CounterÐ Counts up to
three to turn OFF the MIL.
²Misfire DataÐ Data collected during test.
²Test Done This TripÐ Indicates YES when the
test is done.
OPERATION - NON-MONITORED CIRCUITS -
GAS ENGINES
The PCM does not monitor the following circuits,
systems and conditions that could have malfunctions
causing driveability problems. The PCM might not
store diagnostic trouble codes for these conditions.
However, problems with these systems may cause the
PCM to store diagnostic trouble codes for other sys-
tems or components.EXAMPLE:a fuel pressure
problem will not register a fault directly, but could
cause a rich/lean condition or misfire. This could
cause the PCM to store an oxygen sensor or misfire
diagnostic trouble code
25 - 22 EMISSIONS CONTROLBR/BE
EMISSIONS CONTROL (Continued)

CCV HOSE
DESCRIPTION - 8.0L
The 8.0L V-10 engine is equipped with a Crankcase
Ventilation (CCV) system. The CCV system performs
the same function as a conventional PCV system, but
does not use a vacuum controlled valve (PCV valve).
A molded vacuum tube connects manifold vacuum
to the top of the right cylinder head (valve) cover.
The vacuum tube connects to a fixed orifice fitting
(Fig. 1) of a calibrated size 2.6 mm (0.10 inches).
OPERATION - 8.0L
A molded vacuum tube connects manifold vacuum
to the top of the right cylinder head (valve) cover.
The vacuum tube connects to a fixed orifice fitting
(Fig. 1) of a calibrated size 2.6 mm (0.10 inches). The
fitting meters the amount of crankcase vapors drawn
out of the engine.The fixed orifice fitting is grey
in color.A similar fitting (but does not contain a
fixed orifice) is used on the left cylinder head (valve)
cover. This fitting is black in color. Do not inter-
change these two fittings.When the engine is operating, fresh air enters the
engine and mixes with crankcase vapors. Manifold
vacuum draws the vapor/air mixture through the
fixed orifice and into the intake manifold. The vapors
are then consumed during engine combustion.
CRANKCASE VENT HOSE
OPERATION
The crankcase breather/filter is no longer used
with the 3.9L, 5.2L or 5.9L engine.
EVAP/PURGE SOLENOID
DESCRIPTION
All 3.9L/5.2L/5.9L/8.0L gasoline powered engines
use a duty cycle EVAP canister purge solenoid. The
solenoid regulates the rate of vapor flow from the
EVAP canister to the throttle body. The Powertrain
Control Module (PCM) operates the solenoid.
During the cold start warm-up period and the hot
start time delay, the PCM does not energize the sole-
noid. When de-energized, no vapors are purged. The
PCM de-energizes the solenoid during open loop oper-
ation.
The engine enters closed loop operation after it
reaches a specified temperature and the time delay
ends. During closed loop operation, the PCM ener-
gizes and de-energizes the solenoid 5 or 10 times per
second, depending upon operating conditions. The
PCM varies the vapor flow rate by changing solenoid
pulse width. Pulse width is the amount of time the
solenoid energizes. The PCM adjusts solenoid pulse
width based on engine operating condition.
REMOVAL
The duty cycle solenoid is attached to a bracket
mounted to the right inner fender (Fig. 2).
(1) Disconnect electrical wiring connector at sole-
noid (Fig. 2).
(2) Disconnect vacuum harness at solenoid.
(3) Remove solenoid from support bracket.
INSTALLATION
(1) Install solenoid assembly to support bracket.
(2) Connect vacuum harness.
(3) Connect wiring connector.
Fig. 1 Fixed Orifice FittingÐ8.0L V-10 EngineÐ
Typical
1 - VACUUM TUBE
2 - FIXED ORIFICE FITTING
3 - COIL PACKS
4 - ORIFICE FITTING HOSE CONNECTIONS
25 - 32 EVAPORATIVE EMISSIONSBR/BE