DODGE RAM 2002 Service Repair Manual

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.
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 within  375
RPM and load is within  10% 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.
25 - 22 EMISSIONS CONTROLBR/BE
EMISSIONS CONTROL (Continued)

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 follows:
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
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 Factor
must 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'.
BR/BEEMISSIONS CONTROL 25 - 23
EMISSIONS CONTROL (Continued)

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
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 store
diagnostic 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
25 - 24 EMISSIONS CONTROLBR/BE
EMISSIONS CONTROL (Continued)

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 injectoris 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.
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).
BR/BEEMISSIONS CONTROL 25 - 25
EMISSIONS CONTROL (Continued)

AIR INJECTION
TABLE OF CONTENTS
page page
AIR INJECTION
DESCRIPTION - AIR INJECTION SYSTEM....26
OPERATION - AIR INJECTION SYSTEM......28
SPECIFICATIONS
TORQUE - AIR INJECTION SYSTEM.......29
AIR INJECTION PUMP
DESCRIPTION.........................29
OPERATION...........................29
DIAGNOSIS AND TESTING - AIR INJECTION
PUMP..............................29
REMOVAL.............................30INSTALLATION.........................30
AIR PUMP FILTER
REMOVAL.............................30
INSTALLATION.........................30
ONE WAY CHECK VALVE
DESCRIPTION.........................31
OPERATION...........................31
DIAGNOSIS AND TESTING - ONE-WAY
CHECK VALVE........................31
REMOVAL.............................31
INSTALLATION.........................31
AIR INJECTION
DESCRIPTION - AIR INJECTION SYSTEM
The air injection system (Fig. 1), (Fig. 2) or (Fig. 3)
is used on 5.9L V-8 and 8.0L V-10 heavy duty cycle
(HDC) gas powered engines only. The air injection
system consists of:
²A belt-driven air injection (AIR) pump²Two air pressure relief valves
²Rubber connecting air injection hoses with
clamps
²Metal connecting air tubes
²Two one-way check valves
²A replaceable injection pump air filter (8.0L V-10
engine only)
25 - 26 AIR INJECTIONBR/BE

Fig. 1 Air Injection System ComponentsÐTypical
1 - CATALYTIC CONVERTORS (2)
2 - ONE-WAY CHECK VALVES (2)
3-88Y'' CONNECTOR
4 - PRESSURE RELIEF VALVE
5 - HOSE
6 - CLAMPS
7 - HOSE
8 - CLAMP9 - AIR INJECTION PUMP
10 - INLET AIR FITTING
11 - OUTLET AIR FITTING
12 - METAL CONNECTING TUBE
13 - HOSE
14 - CLAMPS
BR/BEAIR INJECTION 25 - 27
AIR INJECTION (Continued)

OPERATION - AIR INJECTION SYSTEM
The air injection system adds a controlled amount
of air to the exhaust gases aiding oxidation of hydro-
carbons and carbon monoxide in the exhaust stream.
The system does not interfere with the ability of the
EGR system (if used) to control nitrous oxide (NOx)
emissions.
5.9L HDC ENGINE:Air is drawn into the pump
through a rubber tube that is connected to a fitting
on the air cleaner housing (Fig. 2).
8.0L V-10 ENGINE:Air is drawn into the pump
through a rubber tube that is connected to a fitting
on the air injection pump filter housing (Fig. 3). Air
is drawn into the filter housing from the front of the
vehicle with rubber tube. This tube is used as a
silencer to help prevent air intake noise at the open-
ing to the pump filter housing. An air filter is located
within the air pump filter housing (Fig. 3).
Air is then compressed by the air injector pump. It
is expelled from the pump and routed into a rubber
tube where it reaches the air pressure relief valve
(Fig. 1). Pressure relief holes in the relief valve willprevent excess downstream pressure. If excess down-
stream pressure occurs at the relief valve, it will be
vented into the atmosphere.
Air is then routed (Fig. 1) from the relief valve,
through a tube, down to a9Y9connector, through the
two one-way check valves and injected at both of the
catalytic convertors (referred to as downstream).
The two one-way check valves (Fig. 1) protect the
hoses, air pump and injection tubes from hot exhaust
gases backing up into the system. Air is allowed to
flow through these valves in one direction only
(towards the catalytic convertors).
Downstream air flow assists the oxidation process
in the catalyst, but does not interfere with EGR oper-
ation (if EGR system is used).
Fig. 2 Air Inlet for Air PumpÐ5.9L HDC Engine
1 - AIR FILTER HOUSING
2 - AIR INLET TUBE
3 - INLET AIR FITTING
4 - AIR INJECTION PUMP
5 - OUTLET AIR FITTING
Fig. 3 Air Inlet and Air Pump Air
1 - INJECTION PUMP AIR FILTER HOUSING
2 - R. F. INNER FENDER
3 - FILTER HOUSING MOUNTING NUT
4 - PRESSURE RELIEF VALVE
5 - HOSE CLAMPS
6 - AIR INJECTION PUMP
7 - AIR INLET REDUCER
8 - LID
25 - 28 AIR INJECTIONBR/BE
AIR INJECTION (Continued)

SPECIFICATIONS
TORQUE - AIR INJECTION SYSTEM
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Air Pump Filter Housing
Nut18
Air Pump Mounting Bolts 40 30
Air Pump Pulley Mounting
Bolts11 105
One-Way Check Valve to
Catalyst Tube33 25
AIR INJECTION PUMP
DESCRIPTION
The air pump is mounted on the front of the
engine and driven by a belt connected to the crank-
shaft pulley (Fig. 4) .
OPERATION
Refer to Air Injection System Description and
Operation for information.
DIAGNOSIS AND TESTING - AIR INJECTION
PUMP
The air injection system and air injection
pump is not completely noiseless.Under normal
conditions, noise rises in pitch as engine speed
increases. To determine if excessive noise is fault of
air injection system, disconnect accessory drive belt
and temporarily operate engine.Do not allow
engine to overheat when operating without
drive belt.
CAUTION: Do not attempt to lubricate the air injec-
tion pump. Oil in the pump will cause rapid deteri-
oration and failure.
Fig. 4 Air Injection Pump MountingÐTypical
1 - PUMP PULLEY
2 - AIR PUMP
3 - AUTOMATIC BELT TENSIONER
4 - PUMP MOUNTING BOLTS (2)
5 - PULLEY BOLTS
BR/BEAIR INJECTION 25 - 29
AIR INJECTION (Continued)

EXCESSIVE BELT NOISE1. Loose belt or defective automatic
belt tensioner.1. Refer to Cooling System.
2. Seized pump. 2. Replace pump.
EXCESSIVE PUMP NOISE
CHIRPING1. Insufficient break-in. 1. Recheck for noise after 1600 km
(1,000 miles) of operation.
EXCESSIVE PUMP NOISE
CHIRPING, RUMBLING, OR
KNOCKING1. Leak in hose. 1. Locate source of leak using soap
solution and correct.
2. Loose hose. 2. Reassemble and replace or tighten
hose clamp.
3. Hose touching other engine parts. 3. Adjust hose position.
4. Relief valve inoperative. 4. Replace relief valve.
5. Check valve inoperative. 5. Replace check valve.
6. Pump mounting fasteners loose. 6. Tighten mounting screws as
specified.
7. Pump failure. 7. Replace pump.
NO AIR SUPPLY.
ACCELERATE ENGINE TO
1500 RPM AND OBSERVE
AIR FLOW FROM HOSES. IF
FLOW INCREASES AS
RPM'S INCREASE, PUMP IS
FUNCTIONING NORMALLY.
IF NOT, CHECK POSSIBLE
CAUSE.1. Loose drive belt. 1. Refer to Cooling System.
2. Leaks in supply hose. 2. Locate leak and repair or replace as
required.
3. Leak at fitting(s). 3. Tighten and replace clamps.
4. Check valve inoperative. 4. Replace check valve.
5. Plugged inlet air filter (8.0L). 5. Replace filter
REMOVAL
The air injection pump does not have any internal
serviceable parts.
(1) Disconnect both of the hoses (tubes) at the air
injection pump.
(2) Loosen, but do not remove at this time, the
three air pump pulley mounting bolts (Fig. 4).
(3) Relax the automatic belt tensioner and remove
the engine accessory drive belt. Refer to Cooling Sys-
tem. See Belt Removal/Installation.
(4) Remove the three air pump pulley bolts and
remove pulley from pump.
(5) Remove the two air pump mounting bolts (Fig.
4) and remove pump from mounting bracket.
INSTALLATION
(1) Position air injection pump to mounting
bracket.
(2) Install two pump mounting bolts to mounting
bracket. Tighten bolts to 40 N´m (30 ft. lbs.) torque.
(3) Install pump pulley and three mounting bolts.
Tighten bolts finger tight.
(4) Relax tension from automatic belt tensioner
and install drive belt. Refer to Cooling System. See
Belt Removal/Installation.(5) Tighten pump pulley bolts to 11 N´m (105 in.
lbs.) torque.
(6) Install hoses and hose clamps at pump.
AIR PUMP FILTER
REMOVAL
The air filter for the air injection pump is located
inside a housing located in right-front side of engine
compartment (Fig. 3) . A rubber hose connects the fil-
ter housing to air injection pump. The filter is used
with 8.0L V-10 engines only.
(1) Remove rubber tubes at filter housing.
(2) Remove filter housing mounting nut and
remove housing.
(3) Remove lid from filter housing (snaps off).
(4) Remove filter from housing.
INSTALLATION
The air filter for the air injection pump is located
inside a housing located in right-front side of engine
compartment (Fig. 3) . A rubber hose connects the fil-
ter housing to air injection pump. The filter is used
with 8.0L V-10 engines only.
25 - 30 AIR INJECTIONBR/BE
AIR INJECTION PUMP (Continued)

(1) Clean inside of housing and lid before install-
ing new filter.
(2) Install filter into housing.
(3) Install lid to filter housing (snaps on).
(4) Position filter housing to fender.
(5) Install mounting nut and tighten to 11 N´m (8
ft. lbs.) torque.
(6) Install rubber tubes and cap at filter housing.
ONE WAY CHECK VALVE
DESCRIPTION
For air injection systems:A pair of one-way
check valves is used with the air injection system.
The check valves (Fig. 1) are located on each of the
air injection downstream tubes.
OPERATION
Each one-way check valve has a one-way dia-
phragm which prevents hot exhaust gases from back-
ing up into the air injection hose and air injection
pump. The check valve will protect the system if theair injection pump belt fails, an air hose ruptures or
exhaust system pressure becomes abnormally high.
DIAGNOSIS AND TESTING - ONE-WAY CHECK
VALVE
The one-way check valves are not repairable. To
determine condition of valve, remove the rubber air
tube from the inlet side of each check valve. Start the
engine. If exhaust gas is escaping through the inlet
side of check valve, it must be replaced.
REMOVAL
(1) Remove the hose clamp at inlet side of valve.
(2) Remove hose from valve.
(3) Remove valve from catalyst tube (unscrew).To
prevent damage to catalyst tube, a backup
wrench must be used on the tube.
INSTALLATION
(1) Install valve to catalyst tube. Tighten to 33
N´m (25 ft. lbs.) torque.
(2) Install hose and hose clamp to valve.
BR/BEAIR INJECTION 25 - 31
AIR PUMP FILTER (Continued)