2001 DODGE RAM sensor

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)

determine if conditions are appropriate for tests to be
run, monitor the parameters for a trip for each test,
and record the results of the test. Following are the
responsibilities of the Task Manager software:
²Test Sequence
²MIL Illumination
²Diagnostic Trouble Codes (DTCs)
²Trip Indicator
²Freeze Frame Data Storage
²Similar Conditions Window
Test Sequence
In many instances, emissions systems must fail
diagnostic tests more than once before the PCM illu-
minates the MIL. These tests are know as 'two trip
monitors.' Other tests that turn the MIL lamp on
after a single failure are known as 'one trip moni-
tors.' A trip is defined as 'start the vehicle and oper-
ate it to meet the criteria necessary to run the given
monitor.'
Many of the diagnostic tests must be performed
under certain operating conditions. However, there
are times when tests cannot be run because another
test is in progress (conflict), another test has failed
(pending) or the Task Manager has set a fault that
may cause a failure of the test (suspend).
²Pending
Under some situations the Task Manager will not
run a monitor if the MIL is illuminated and a fault is
stored from another monitor. In these situations, the
Task Manager postpones monitorspendingresolu-
tion of the original fault. The Task Manager does not
run the test until the problem is remedied.
For example, when the MIL is illuminated for an
Oxygen Sensor fault, the Task Manager does not run
the Catalyst Monitor until the Oxygen Sensor fault is
remedied. Since the Catalyst Monitor is based on sig-
nals from the Oxygen Sensor, running the test would
produce inaccurate results.
²Conflict
There are situations when the Task Manager does
not run a test if another monitor is in progress. In
these situations, the effects of another monitor run-
ning could result in an erroneous failure. If thiscon-
flictis present, the monitor is not run until the
conflicting condition passes. Most likely the monitor
will run later after the conflicting monitor has
passed.
For example, if the Fuel System Monitor is in
progress, the Task Manager does not run the EGR
Monitor. Since both tests monitor changes in air/fuel
ratio and adaptive fuel compensation, the monitors
will conflict with each other.
²Suspend
Occasionally the Task Manager may not allow a two
trip fault to mature. The Task Manager willsus-pendthe maturing of a fault if a condition exists
that may induce an erroneous failure. This prevents
illuminating the MIL for the wrong fault and allows
more precis diagnosis.
For example, if the PCM is storing a one trip fault
for the Oxygen Sensor and the EGR monitor, the
Task Manager may still run the EGR Monitor but
will suspend the results until the Oxygen Sensor
Monitor either passes or fails. At that point the Task
Manager can determine if the EGR system is actu-
ally failing or if an Oxygen Sensor is failing.MIL Illumination
The PCM Task Manager carries out the illumina-
tion of the MIL. The Task Manager triggers MIL illu-
mination upon test failure, depending on monitor
failure criteria.
The Task Manager Screen shows both a Requested
MIL state and an Actual MIL state. When the MIL is
illuminated upon completion of a test for a third trip,
the Requested MIL state changes to OFF. However,
the MIL remains illuminated until the next key
cycle. (On some vehicles, the MIL will actually turn
OFF during the third key cycle) During the key cycle
for the third good trip, the Requested MIL state is
OFF, while the Actual MILL state is ON. After the
next key cycle, the MIL is not illuminated and both
MIL states read OFF.
Diagnostic Trouble Codes (DTCs)
With OBD II, different DTC faults have different
priorities according to regulations. As a result, the
priorities determine MIL illumination and DTC era-
sure. DTCs are entered according to individual prior-
ity. DTCs with a higher priority overwrite lower
priority DTCs.
Priorities
²Priority 0 ÐNon-emissions related trouble codes
²Priority 1 Ð One trip failure of a two trip fault
for non-fuel system and non-misfire.
²Priority 2 Ð One trip failure of a two trip fault
for fuel system (rich/lean) or misfire.
²Priority3ÐTwotrip failure for a non-fuel sys-
tem and non-misfire or matured one trip comprehen-
sive component fault.
²Priority4ÐTwotrip failure or matured fault
for fuel system (rich/lean) and misfire or one trip cat-
alyst damaging misfire.
Non-emissions related failures have no priority.
One trip failures of two trip faults have low priority.
Two trip failures or matured faults have higher pri-
ority. One and two trip failures of fuel system and
misfire monitor take precedence over non-fuel system
and non-misfire failures.
25 - 20 EMISSIONS CONTROLBR/BE
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)

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 or fuel system diag-
nostic 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.
CYLINDER COMPRESSION
The PCM cannot detect uneven, low, or high engine
cylinder compression.
EXHAUST SYSTEM
The PCM cannot detect a plugged, restricted or
leaking exhaust system, although it may set a fuel
system fault.
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, also
during diagnostic.
PCM CONNECTOR ENGAGEMENT
The PCM may not be able to determine spread or
damaged connector pins. However, it might storediagnostic trouble codes as a result of spread connec-
tor pins.
OPERATION - NON-MONITORED CIRCUITS -
DIESEL
The PCM and/or the ECM will not monitor certain
malfunctioning circuits or components that could
cause driveability problems. Also, a Diagnostic Trou-
ble Code (DTC) might not be stored for these mal-
functions. However, problems with these circuits or
components may cause the PCM/ECM to store DTC's
for other circuits or components.EXAMPLES:A cyl-
inder with low compression will not set a DTC
directly, but may cause an engine misfire. This in
turn may cause the ECM to set a DTC for an engine
misfire. Or, a dirty or plugged air filter will not set a
DTC directly, but may cause lack of turbocharger
boost. This in turn may cause the ECM to set a DTC
for a boost pressure malfunction.
FUEL PRESSURE
Primary fuel pressure from the fuel tank to the
fuel injection pump is supplied by the low-pressure
fuel transfer pump. High-pressure to the fuel injec-
tors is supplied by the fuel injection pump. The ECM
cannot detect actual fuel pressure, a clogged fuel fil-
ter, clogged fuel screen, or a pinched fuel supply or
return line. However, a DTC may be set due to an
engine misfire.
CYLINDER COMPRESSION
The ECM cannot detect uneven, low, or high
engine cylinder compression. However, these could
result in a possible misfire which may set a DTC.
EXHAUST SYSTEM
The ECM cannot detect a plugged, restricted or
leaking exhaust system. However, DTC's may be set
for engine misfire, high intake manifold temperature,
high engine coolant temperature, turbocharger over-
boost or turbocharger underboost.
FUEL INJECTOR MECHANICAL MALFUNCTIONS
The ECM 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 possible
misfire which may set a DTC.
EXCESSIVE OIL CONSUMPTION
The ECM cannot determine excessive oil consump-
tion. However, if excess oil consumption is high
enough, it could result in a possible engine misfire
which may set a DTC.
BR/BEEMISSIONS CONTROL 25 - 23
EMISSIONS CONTROL (Continued)

AIR FLOW
The ECM cannot detect a clogged, restricted or
dirty air filter element, or a restriction in the air
inlet system. However, these could result in a possi-
ble misfire which may set a DTC.
AIR PRESSURE LEAKS
The ECM cannot detect leaks or restrictions in the
air intake system. However, these could cause the
ECM to store a Manifold Air Pressure (MAP) sensor
DTC (boost pressure problem detected).PCM/ECM SYSTEM GROUNDS
The PCM/ECM cannot directly determine poor sys-
tem grounds. However, one or more DTC's may be
generated as a result of poor grounds.
PCM/ECM CONNECTOR ENGAGEMENT
The PCM/ECM may not be able to determine
spread, damaged or corroded connector pins. How-
ever, it might store DTC's as a result of spread con-
nector pins (circuits that are open).
25 - 24 EMISSIONS CONTROLBR/BE
EMISSIONS CONTROL (Continued)

ABS INDICATOR - DESCRIPTION.........8J-14
ABS INDICATOR - OPERATION..........8J-14
A/C APPLICATION TABLE,
SPECIFICATIONS......................24-8
A/C COMPRESSOR - DESCRIPTION......24-46
A/C COMPRESSOR - DIAGNOSIS AND
TESTING...........................24-46
A/C COMPRESSOR - INSTALLATION......24-47
A/C COMPRESSOR - OPERATION........24-46
A/C COMPRESSOR - REMOVAL.........24-47
A/C COMPRESSOR CLUTCH -
DESCRIPTION.......................24-13
A/C COMPRESSOR CLUTCH -
INSPECTION........................24-16
A/C COMPRESSOR CLUTCH -
INSTALLATION.......................24-16
A/C COMPRESSOR CLUTCH -
OPERATION.........................24-13
A/C COMPRESSOR CLUTCH - REMOVAL . . 24-14
A/C COMPRESSOR CLUTCH BREAK-IN -
STANDARD PROCEDURE...............24-13
A/C COMPRESSOR CLUTCH COIL -
DIAGNOSIS AND TESTING.............24-13
A/C COMPRESSOR CLUTCH RELAY -
DESCRIPTION.......................24-17
A/C COMPRESSOR CLUTCH RELAY -
DIAGNOSIS AND TESTING.............24-17
A/C COMPRESSOR CLUTCH RELAY -
INSTALLATION.......................24-18
A/C COMPRESSOR CLUTCH RELAY -
OPERATION.........................24-17
A/C COMPRESSOR CLUTCH RELAY -
REMOVAL..........................24-18
A/C CONDENSER - DESCRIPTION........24-48
A/C CONDENSER - INSTALLATION.......24-49
A/C CONDENSER - OPERATION..........24-48
A/C CONDENSER - REMOVAL...........24-49
A/C EVAPORATOR - DESCRIPTION.......24-52
A/C EVAPORATOR - INSTALLATION......24-53
A/C EVAPORATOR - OPERATION.........24-53
A/C EVAPORATOR - REMOVAL..........24-53
A/C HEATER CONTROL - DESCRIPTION . . . 24-18
A/C HEATER CONTROL - DIAGNOSIS
AND TESTING.......................24-19
A/C HEATER CONTROL - INSTALLATION . . . 24-20
A/C HEATER CONTROL - OPERATION.....24-18
A/C HEATER CONTROL - REMOVAL......24-19
A/C HIGH PRESSURE SWITCH -
DESCRIPTION.......................24-20
A/C HIGH PRESSURE SWITCH -
DIAGNOSIS AND TESTING.............24-20
A/C HIGH PRESSURE SWITCH -
INSTALLATION.......................24-21
A/C HIGH PRESSURE SWITCH -
OPERATION.........................24-20
A/C HIGH PRESSURE SWITCH -
REMOVAL..........................24-21
A/C LINE COUPLERS - DESCRIPTION.....24-40
A/C LINE COUPLERS - OPERATION......24-41
A/C LINE COUPLERS - STANDARD
PROCEDURE........................24-43
A/C LOW PRESSURE SWITCH -
DESCRIPTION.......................24-21
A/C LOW PRESSURE SWITCH -
DIAGNOSIS AND TESTING.............24-21
A/C LOW PRESSURE SWITCH -
INSTALLATION.......................24-22
A/C LOW PRESSURE SWITCH -
OPERATION.........................24-21
A/C LOW PRESSURE SWITCH -
REMOVAL..........................24-21
A/C ORIFICE TUBE - DESCRIPTION.......24-53
A/C ORIFICE TUBE - OPERATION........24-53
A/C ORIFICE TUBE - REMOVAL..........24-54
A/C PERFORMANCE - DIAGNOSIS AND
TESTING............................24-2
ACCELERATOR PEDAL - INSTALLATION . . . 14-37
ACCELERATOR PEDAL - REMOVAL.......14-37
ACCELERATOR PEDAL POSITION
SENSOR - DESCRIPTION
...............14-91
ACCELERATOR PEDAL POSITION
SENSOR - INSTALLATION
..............14-93
ACCELERATOR PEDAL POSITION
SENSOR - OPERATION
................14-91
ACCELERATOR PEDAL POSITION
SENSOR - REMOVAL
..................14-91
ACCESSORY DRIVE BELT - DIAGNOSIS
AND TESTING
................7-24,7-27,7-31ACCUMULATOR - DESCRIPTION.........24-54
ACCUMULATOR - DESCRIPTION . 21-191,21-362,
21-537,21-707
ACCUMULATOR - INSPECTION . . 21-192,21-363,
21-538,21-708
ACCUMULATOR - INSTALLATION........24-55
ACCUMULATOR - OPERATION..........24-54
ACCUMULATOR - OPERATION . . . 21-191,21-362,
21-537,21-708
ACCUMULATOR - REMOVAL............24-54
ACTUATION TEST MODE - DESCRIPTION,
CIRCUIT.............................25-1
ACTUATOR - INSTALLATION, BLEND
DOOR.............................24-26
ACTUATOR - INSTALLATION, HEAT/
DEFROST DOOR.....................24-27
ACTUATOR - INSTALLATION, INSIDE
HANDLE.......................23-71,23-80
ACTUATOR - INSTALLATION, PANEL/
DEFROST DOOR.....................24-27
ACTUATOR - INSTALLATION,
RECIRCULATION DOOR................24-28
ACTUATOR - REMOVAL, BLEND DOOR....24-25
ACTUATOR - REMOVAL, HEAT/DEFROST
DOOR.............................24-26
ACTUATOR - REMOVAL, INSIDE HANDLE . 23-71,
23-80
ACTUATOR - REMOVAL, PANEL/DEFROST
DOOR.............................24-27
ACTUATOR - REMOVAL, RECIRCULATION
DOOR.............................24-27
ADAPTER - INSTALLATION, DEFROSTER
AND DEMISTER DUCT.................24-35
ADAPTER - REMOVAL, DEFROSTER AND
DEMISTER DUCT.....................24-35
ADAPTER BRACKET - INSTALLATION,
CAB CHASSIS........................13-9
ADAPTER BRACKET - REMOVAL, CAB
CHASSIS............................13-9
ADAPTER HOUSING SEAL -
INSTALLATION.................21-132,21-87
ADAPTER HOUSING SEAL - REMOVAL . . 21-132,
21-87
ADDING ADDITIONAL COOLANT -
STANDARD PROCEDURE................7-16
ADDITIONAL COOLANT - STANDARD
PROCEDURE, ADDING..................7-16
ADHESIVE LOCATIONS, SPECIFICATIONS
- STRUCTURAL......................23-44
ADJUSTER - DIAGNOSIS & TESTING,
POWER LUMBAR....................8N-18
ADJUSTER - INSTALLATION, SEAT BELT
TURNING LOOP.....................8O-29
ADJUSTER - INSTALLATION, SEAT
TRACK............................23-143
ADJUSTER - REMOVAL, SEAT BELT
TURNING LOOP.....................8O-29
ADJUSTER - REMOVAL, SEAT TRACK....23-143
ADJUSTER ASSEMBLY - INSTALLATION,
ROCKER ARM........................9-85
ADJUSTER ASSEMBLY - REMOVAL,
ROCKER ARM........................9-85
ADJUSTER ASSY - CLEANING, ROCKER
ARM ..............................9-262
ADJUSTER ASSY - DESCRIPTION,
ROCKER ARM.......................9-261
ADJUSTER ASSY - INSPECTION,
ROCKER ARM.......................9-262
ADJUSTER ASSY - INSTALLATION,
ROCKER ARM.............9-142,9-200,9-263
ADJUSTER ASSY - REMOVAL, ROCKER
ARM ....................9-142,9-200,9-261
ADJUSTER KNOB - INSTALLATION,
TURNING LOOP HEIGHT...............8O-30
ADJUSTER KNOB - REMOVAL, TURNING
LOOP HEIGHT.......................8O-30
ADJUSTMENT - STANDARD
PROCEDURE, COMPASS VARIATION......8M-4
ADJUSTMENT AND VERIFICATION -
STANDARD PROCEDURE, VALVE LASH....9-256
ADJUSTMENT, BANDS . . . 21-193,21-364,21-539,
21-709
ADJUSTMENT, CABLE TENSIONER
........5-40
ADJUSTMENT, CARGO DOOR
...........23-78
ADJUSTMENT, CENTER BEARING -
CENTER BEARING
.....................3-10
ADJUSTMENT, FRONT DOOR FORE/AFT
. . . 23-68
ADJUSTMENT, FRONT DOOR IN/OUT
.....23-69ADJUSTMENT, FRONT DOOR LATCH......23-72
ADJUSTMENT, FRONT DOOR UP/DOWN . . . 23-69
ADJUSTMENT, FRONT FASCIA...........13-2
ADJUSTMENT, HOOD................23-100
ADJUSTMENT, LATCH................23-100
ADJUSTMENT, LATCH STRIKER........23-102
ADJUSTMENT, REAR BRAKE DRUM.......5-34
ADJUSTMENT, SHIFT LEVER....21-853,21-888,
21-925
ADJUSTMENT, SHIFT MECHANISM.....21-252,
21-423,21-596,21-769
ADJUSTMENTS, FOG LAMP UNIT........8L-12
ADJUSTMENTS, FRONT AXLE - 216FBI....3-17
ADJUSTMENTS, FRONT AXLE - 248FBI....3-50
ADJUSTMENTS, GEAR.................19-16
ADJUSTMENTS, HEADLAMP UNIT.......8L-21
ADJUSTMENTS, REAR AXLE - 248RBI....3-114
ADJUSTMENTS, REAR AXLE - 267RBI....3-145
ADJUSTMENTS, REAR AXLE - 286RBI....3-174
ADJUSTMENTS, REAR AXLE - 9 1/4 .......3-84
ADJUSTMENTS, TRANSMISSION
THROTTLE VALVE CABLE . 21-254,21-425,21-598,
21-771
ADJUSTMENTS, VALVE BODY . . . 21-304,21-476,
21-646,21-818
AFTER AN AIRBAG DEPLOYMENT -
STANDARD PROCEDURE, SERVICE.......8O-4
AIR BLEED - STANDARD PROCEDURE....14-57
AIR CHECKING TRANSMISSION CLUTCH
AND BAND OPERATION - DIAGNOSIS
AND TESTING................21-147,21-318
AIR CLEANER ELEMENT - INSTALLATION . . 9-245
AIR CLEANER ELEMENT - REMOVAL.....9-244
AIR CONDITIONER - DESCRIPTION,
HEATER .............................24-1
AIR CONDITIONER - OPERATION,
HEATER .............................24-1
AIR CONDITIONING - INSTALLATION,
WATER PUMP BYPASS HOSE WITH.......7-77
AIR CONDITIONING - INSTALLATION,
WATER PUMP BYPASS HOSE
WITHOUT............................7-78
AIR CONDITIONING - REMOVAL, WATER
PUMP BYPASS HOSE WITH.............7-74
AIR CONDITIONING - REMOVAL, WATER
PUMP BYPASS HOSE WITHOUT..........7-77
AIR CONTROL MOTOR - DESCRIPTION,
IDLE...............................14-41
AIR CONTROL MOTOR - OPERATION,
IDLE...............................14-41
AIR COOLER AND PLUMBING -
CLEANING, CHARGE..................11-18
AIR COOLER AND PLUMBING -
DESCRIPTION, CHARGE...............11-17
AIR COOLER AND PLUMBING -
INSPECTION, CHARGE.................11-18
AIR COOLER AND PLUMBING -
INSTALLATION, CHARGE...............11-18
AIR COOLER AND PLUMBING -
OPERATION, CHARGE.................11-17
AIR COOLER AND PLUMBING -
REMOVAL, CHARGE..................11-17
AIR DAM - INSTALLATION, FRONT........13-2
AIR DAM - REMOVAL, FRONT...........13-1
AIR EXHAUSTER - INSTALLATION.......23-77
AIR EXHAUSTER - REMOVAL...........23-77
AIR HEATER - DESCRIPTION, INTAKE....14-100
AIR HEATER - INSTALLATION, INTAKE . . . 14-101
AIR HEATER - OPERATION, INTAKE.....14-100
AIR HEATER - REMOVAL, INTAKE.......14-100
AIR HEATER RELAY - DESCRIPTION,
INTAKE............................14-101
AIR HEATER RELAY - INSTALLATION,
INTAKE............................14-102
AIR HEATER RELAY - OPERATION,
INTAKE............................14-102
AIR HEATER RELAY - REMOVAL, INTAKE . 14-102
AIR IN FUEL SYSTEM - DIAGNOSIS AND
TESTING...........................14-56
AIR INJECTION PUMP - DESCRIPTION....25-28
AIR INJECTION PUMP - DIAGNOSIS AND
TESTING...........................25-28
AIR INJECTION PUMP - INSTALLATION . . . 25-29
AIR INJECTION PUMP - OPERATION
.....25-28
AIR INJECTION PUMP - REMOVAL
.......25-29
AIR INJECTION SYSTEM - DESCRIPTION
. . 25-25
AIR INJECTION SYSTEM - OPERATION
....25-27
AIR INJECTION SYSTEM - TORQUE
......25-28
BR/BEINDEX 1
Description Group-Page Description Group-Page Description Group-Page