
25 - 16
EMISSION
CONTROL
SYSTEMS
•
DOWNSTREAM
dciicc
HOSE
RELIEF
HOLES
J9325-37
Fig.
2 Air Injection
Pump
Operation cessive noise is fault of air injection system, discon
nect drive belt and operate engine.
CAUTION:
Do not lubricate air injection pump. Wipe
all oil off of pump
housing.
Oil in the pump
will
cause
rapid deterioration and failure.
CAUTION:
Completely cover the air pump before
cleaning
the engine or underhood compartment. Refer to the Component Removal/Installation section
of this group for air pump replacement procedures.
CHECK
VALVE—AIR
INJECTION
TUBE
A check valve (Fig. 1) is located on each of the air
injection downstream tubes. The check valve has a one-way diaphragm which pre
vents hot exhaust gases from backing up into the hose and pump. The check valve will protect the system if
the air injection pump belt fails, an air hose ruptures or exhaust system pressure becomes abnormally high.
TESTING
CHECK
VALVE
The 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
valve, it must be replaced.
Refer to the Component Removal/Installation section
of this group for check valve replacement procedures.
AIR
PUMP
DIAGNOSIS
Condition
Possible
Cause
Correction
EXCESSIVE
BELT
NOISE
(a)
Loose
belt
or defective auto,
belt
tensioner. (a) Refer to
Group
7,
Cooling.
(b) Seized pump. (b) Replace pump.
EXCESSIVE
PUMP
NOISE.
CHIRPING
(a) Insufficient break-in.
(a) Recheck for
noise
after
1600 km.
(1,000
miles) of operation.
EXCESSIVE
PUMP
NOISE CHIRPING,
RUMBUNG, OR KNOCKING (a) Leak in
hose.
(a) Locate
source
of leak
using
soap
solution
and correct.
(b)
Loose
hose.
(b)
Reassemble
and replace or tighten
hose
clamp.
(c)
Hose
touching other engine parts. (c) Adjust
hose
position.
(d) Relief valve inoperative. (d) Replace
relief
valve.
(e) Check valve inoperative. (e) Replace check valve.
(f)
Pump
mounting fasteners
loose.
(f) Tighten mounting
screws
as specified.
(g)
Pump
failure.
(g)
Replace pump.
NO AIR SUPPLY (ACCELERATE ENGINE TO 1500 RPM AND OBSERVE AIR
FLOW
FROM
HOSES.
IF THE
FLOW
INCREASES
AS
THE
RPM'S
INCREASE, THE
PUMP
IS
FUNCTION
ING NORMALLY. IF NOT, CHECK POSSIBLE
CAUSE.
(a)
Loose
drive belt.
(b)
Leaks
in
supply
hose.
(c) Leak at fitting(s). (a) Refer to
Group
7,
Cooling.
(b) Locate leak and repair or replace as required.
(c) Tighten or replace
clamps.
(d) Check valve inoperative. (d) Replace check valve.
J9325-38

•
EMISSION
CONTROL SYSTEMS
25 - 17
COMPONENT REMOVAL/INSTALLATION
INDEI
page
Air
Filter/Filter
Housing—Diesel Engines
17
Air
Filter/Filter
Housing—Gas Engines
17
Air
Injection
Pump
17
Air
Injection
Pump Relief Valve
18
Check
Valve—Air
Injection
Tube
18
Coolant Temperature
Sensor
. 18
EGR
Tube—Gas Powered Engines
19
EGR
Valve
19
AIR FILTER/FILTER HOUSING-GAS ENGINES
REMOVAL/INSTALLATION Remove crankcase breather/filter hose at side of air
filter housing. Remove wingnut (Fig. 1) and remove
housing from engine. Check condition of gasket at
throttle body and replace as necessary. To replace air filter element only: Remove wingnut
and air filter housing cover (Fig. 1). Clean inside of
housing before replacing filter. Housing removal is not necessary for filter replacement.
^
WING NUT
COVER
:
GASKET
| I
MOUNTING
STUD
Fig.
1 Air
Filter
Housing—Gas
Powered
Engines—Typical
page
Electric
EGR Transducer (EET)
20
EVAP
Canister
20
EVAP
Canister Purge Solenoid
20
Fuel Tank
Filler
Tube
Cap . 21
Oxygen
(02)
Sensor
21
Powertrain Control Module (PCM)
21
Pressure
Relief/Rollover Valve
21
If housing-to-throttle body mounting stud is being
installed, tighten to 10 N»m (90 in. lbs.) torque. In stall housing to engine and tighten wingnut to 1.5
N»m (15 in. lbs.) torque.
AIR FILTER/FILTER HOUSING-DIESEL ENGINES
REMO
VAL/INSTALLA
TION Remove the hose clamp at air filter housing (Fig.
2).
Remove mounting nuts and remove air filter
housing from vehicle.
To replace air filter element only: Remove hose clamp
and hose at air filter housing inlet tube. Remove three
wingnuts and air filter housing cover (Figs. 2 and 3). Clean inside of housing before replacing filter. Housing
removal is not necessary for filter replacement.
When installing a new air filter element, push el
ement into cover. Be sure it is pushed into tabs in
back of filter housing. Install wing nuts.
If housing had been removed, install mounting
nuts and tighten to 10 N»m (95 in. lbs.) torque.
AIR INJECTION PUMP
REMOVAL (1) Remove the relief valve hose clamp (Fig. 4) and
remove hose at relief valve.
(2) Remove relief valve from air pump (two bolts)
(Fig. 4). (3) Loosen (but do not remove at this time) the
three air pump pulley mounting bolts (number 2—figure 4).
(4) Relax the automatic belt tensioner and remove
the engine accessory drive belt. Refer to Group 7, Cooling System. See Belt Removal/Installation.
(5) Remove the three air pump pulley bolts and re
move pulley from pump.
(6) Remove the two air pump mounting bolts
(number
1—figure
4) and remove pump from mount
ing bracket.

•
EMISSION
CONTROL SYSTEMS
25 - 19
EGR
VALVE
REMOVAL
The EGR valve and the electric EGR transducer
(EET) are serviced as one unit.
(1) Disconnect vacuum hose to EGR valve/trans
ducer assembly. Note position of hoses on EGR valve
and transducer for easier installation.
(2) Remove EGR mounting bolts (Fig. 5).
Fig.
5 EGR
Valve
Mounting
Bolts
(3) Remove EGR valve and gasket. Discard old
gasket. Clean intake manifold mating surface and
check for cracks.
INSTALLATION
(1) Place new EGR gasket on intake manifold. (2) Install EGR valve. Tighten mounting bolts to
23 N*m (200 in. lbs.) torque. (3) Connect vacuum hose to valve/transducer as
sembly.
EGR
TUBE-GAS POWERED ENGINES
REMOVAL
(1) Remove air filter housing.
(2) Remove the spark plug cable loom and plug ca
bles from valve cover mounting stud at rear of right
valve cover. Position spark plug cables to top of valve cover.
(3) Disconnect two vacuum hoses at exhaust gas
recirculation (EGR) valve. (4) Remove 2 EGR valve mounting bolts (Fig. 5)
and remove EGR valve. Discard old gasket.
(5) Disconnect electrical connector at engine oil
pressure sending unit.
(6) To prevent damage to oil pressure sending unit,
a special tool, such as number C-4597 must be used
(Fig. 6). Remove sending unit from engine.
(7) Loosen EGR tube mounting nut at intake man
ifold (Fig. 7).
Fig.
6 Oil
Pressure
Sending
Unit—Removal/Installation
Fig.
7 EGR Tube—Typical
(8) Remove EGR tube mounting bolts at exhaust
manifold (Fig. 7) and remove EGR tube.
INSTALLATION
(1) Clean the EGR tube and exhaust manifold (at
EGR tube mounting point) of any old gasket mate
rial.
(2)
Install a new gasket to exhaust manifold end of
EGR tube. (3) Install EGR tube to both manifolds. Tighten
mounting nut at intake manifold. Tighten two
mounting bolts at exhaust manifold to 23 N»m (204 in. lbs.) torque.
(4) Coat the threads of the oil pressure sending
unit with thread sealant. Do not allow any of the
thread sealant to get into the sending unit opening
or the opening at the engine. Install sending unit to

25 - 20
EMISSION CONTROL SYSTEMS
• engine and tighten to 14 N*m (130 in. lbs.) torque.
Install electrical connector to sending unit.
(5) Clean the intake manifold and EGR valve of
any old gasket material.
(6) Install a new EGR valve gasket to intake man
ifold. (7) Install EGR valve to intake manifold. Tighten
two mounting bolts to 23 N*m (200 in. lbs.) torque.
(8) Install vacuum lines to EGR valve.
(9) Install spark plug cable loom and plug cables to
valve cover mounting stud.
(10) Install air filter housing.
ELECTRIC EGR TRANSDUCER
(EET) The EGR valve and the EET are serviced as one
unit. Also refer to EGR valve removal/installation.
REMOVAL
(1) Remove air filter housing.
(2) Disconnect wiring connector at EET (Fig. 8). (3) Disconnect hoses at EET. Note position of hoses
for easier installation.
(4) Remove EET from engine.
INSTALLATION (1) Position EET to engine and connect hoses.
(2) Connect wiring connector. (3) Install air filter housing.
ELECTRICAL
CONNECTOR
TRANSDUCER
J9325-15
Fig.
8 Electric EGR Transducer (EET)—Typical
EVAP
CANISTER
The EVAP canister is mounted in the engine com
partment on the right side wheel well (Fig. 9).
REMOVAL
(1) Remove fuel tubes/lines at EVAP canister.
Note location of tubes/lines before removal for easier
installation. (2) Remove mounting bolt at canister mounting
strap (Fig. 9).
(3) Remove canister and two-piece strap from
mounting bracket.
CANISTER
MOUNTING
STRAPS
CANISTER
MOUNTING
BRACKET RIGHT FRONT
INNER FENDER
MOUNTING
BOLT
EVAP
CANISTER
J9325-36
Fig.
9
EVAP
Canister Removal/Installation INSTALLATION
(1) Position canister to mounting bracket.
(2) Install canister and both mounting straps to
mounting bracket.
(3) Install canister bolt and tighten to 10 N*m (95
in. lbs.) torque.
(4) Install fuel tubes/lines to canister.
EVAP
CANISTER PURGE SOLENOID
REMOVAL
(1) Remove air filter housing.
(2) Disconnect wiring connector at solenoid (Fig.
10). BRACKET
MOUNTING
NUT
ELECTRICAL
CONNECTOR
CANISTER PURGE
SOLENOID/BRACKET VACUUM
CONNECTOR
J9214-50
Fig.
10
EVAP
Canister
Purge
Solenoid—
Typical
(3) Disconnect vacuum harness at solenoid (Fig.
10).

•
EMISSION CONTROL SYSTEMS 25 - 21 (4) Remove solenoid and its support bracket from
intake manifold (one bolt—5.2L/5.9L engine, one
nut—3.9L engine). (5) Remove EVAP canister purge solenoid from en
gine.
INSTALLATION
(1) Install EVAP canister purge solenoid and its
mounting bracket to intake manifold.
(2) Connect vacuum harness and wiring connector.
(3) Install air filter housing.
FUEL TANK FILLER TUBE CAP If replacement of the fuel filler tube cap (Fig. 11) is
necessary, it must be replaced with an identical cap
to be sure of correct system operation.
CAUTION:
Remove
the
fuel
tank
filler
tube
cap to
relieve
fuel
tank
pressure.
The cap
must
be re
moved
prior
to
disconnecting
any
fuel
system
com
ponent
or
before
draining
the
fuel
tank.
PLASTIC
GASKET
RN348
Fig.
11
Fuel
Tank
Filler
Tube Cap—Typical
OXYGEN (02) SENSOR For description, operation, diagnosis and removal/
installation procedures of the 02 sensor, refer to Group 14, Fuel Systems. POWERTRAIN CONTROL MODULE (PCM)
For removal and installation procedures, refer to
Group 14, Fuel Systems.
PRESSURE RELIEF/ROLLOWER WALWE For removal and installation procedures, refer to
the Fuel Tank section of Group 14, Fuel Systems.

COMPONENT AND SYSTEM INDEX
Name
Group-page
AUDIO
SYSTEMS
8F-1
SERVICE
PROCEDURES 8F-7
TEST PROCEDURES 8F-2
BATTERY/STARTER/GENERATOR SERVICE 8B-1 BATTERY SERVICE PROCEDURES 8B-1
GENERATOR SERVICE 8B-6
SPECIFICATIONS 8B-9
STARTER SERVICE PROCEDURES 8B-4
BODY COMPONENTS 23-1 CAB/BODY INTERIOR COMPONENTS
23-35
DOORS
23-21
EXTERIOR COMPONENTS 23-1
FIXED GLASS
23-29
PAINT
CODE CHART
23-54
REFINISHING PROCEDURES
23-54
BRAKES
5-1 BENDIX DISC BRAKE 5-37 BRAKE ADJUSTMENTS-BRAKE BLEEDING 5-7
BRAKE DIAGNOSIS 5-3
CHRYSLER
DISC BRAKE 5-27 DRUM BRAKES—ELEVEN INCH 5-46
DRUM BRAKES-TWELVE INCH 5-50
GENERAL INFORMATION 5-1 MASTER CYLINDER—COMBINATION VALVE-BRAKE
LINES 5-10
PARKING BRAKES 5-56
POWER BRAKE BOOSTER-BRAKE PEDAL 5-20 POWER BRAKE VACUUM PUMP-DIESEL ENGINE. . 5-22
REAR
WHEEL ANTILOCK
(RWAL)
BRAKES 5-59
SPECIFICATIONS 5-65
CHIME/BUZZER WARNING
SYSTEMS
8U-1
CLUTCH 6-1 CLUTCH DIAGNOSIS 6-2 CLUTCH SERVICE 6-11
COOLING SYSTEM 7-1
DIAGNOSIS 7-4
ENGINE ACCESSORY DRIVE BELTS 7-40
ENGINE BLOCK HEATERS 7-48
SERVICE
PROCEDURES 7-15 SPECIFICATIONS 7-49
ELECTRICAL 8A-1 BATTERY TEST PROCEDURES 8A-2
ENGINE STARTER MOTOR TEST PROCEDURES.... 8A-9
GENERAL INFORMATION 8A-1
GENERATOR TEST PROCEDURES ON VEHICLE . . . 8A-13
GROUP INDEX 8A-1
SPECIFICATIONS 8A-18
BATTERY/STARTING/CHARGING
SYSTEMS
DIAGNOSTICS 8A-1
EMISSION
CONTROL
SYSTEMS.
25-1 AIR INJECTION SYSTEM—5.9L HDC-GAS ENGINE . 25-15 COMPONENT REMOVAL/INSTALLATION 25-17 EVAPORATIVE EMISSION CONTROLS 25-6
EXHAUST EMISSION CONTROLS 25-10
GENERAL INFORMATION 25-1
ENGINES 9-1 3.9L ENGINE SERVICE PROCEDURES 9-17 5.2L ENGINE SERVICE PROCEDURES 9-47
5.9L (DIESEL) ENGINE SERVICE PROCEDURES . . . 9-107
Name
Group-page
5.9L ENGINE SERVICE PROCEDURES 9-77 ENGINE DIAGNOSIS 9-5
STANDARD SERVICE PROCEDURES 9-1
EXHAUST SYSTEM AND INTAKE MANIFOLD 11-1
EXHAUST SYSTEM DIAGNOSIS 11-3
GENERAL INFORMATION 11-1
SERVICE
PROCEDURES (DIESEL ENGINES) 11-17
SERVICE
PROCEDURES (GASOLINE ENGINES) 11-4
SPECIFICATIONS 11-27
FRAME AND BUMPERS 13-1 ATTACHED COMPONENTS 13-30
BUMPERS
13-1
FRAME 13-20
SNOW PLOW 13-3
FRONT SUSPENSION AND AXLE 2-1 FRONT SUSPENSION—2WD VEHICLES 2-7
FRONT SUSPENSION—4WD VEHICLES 2-14 FRONT WHEEL ALIGNMENT 2-3
GENERAL INFORMATION 2-1 MODEL 44 FRONT AXLE 2-17
MODEL 60 FRONT AXLE 2-49
TORQUE SPECIFICATIONS 2-75
FUEL SYSTEM 14-1 ACCELERATOR PEDAL AND THROTTLE CABLE . . . 14-25
DIESEL
FUEL INJECTION—COMPONENT DESCRIPTION/SYSTEM OPERATION 14-76
DIESEL
FUEL INJECTION-GENERAL DIAGNOSIS. . 14-88
DIESEL
FUEL INJECTION-SERVICE
PROCEDURES
14-106
FUEL DELIVERY SYSTEM-EXCEPT DIESEL 14-3
FUEL DELIVERY-DIESEL ENGINE 14-15 FUEL TANKS 14-20
GENERAL INFORMATION 14-1 MULTI-PORT FUEL INJECTION (MPI)-COMPONENT DESCRIPTION/SYSTEM OPERATION-EXCEPT
DIESEL
14-29
MULTI-PORT FUEL INJECTION
(MPlj-COMPONENT
REMOVAL/INSTALLATION-EXCEPT DIESEL .... 14-64
MULTI-PORT FUEL INJECTION (MPI)—GENERAL DIAGNOSIS-EXCEPT DIESEL 14-43
SERVICE
ADJUSTMENTS-DIESEL
14-122
SPECIFICATIONS
14-123
HEATING AND AIR CONDITIONING 24-1 CLIMATE CONTROL SYSTEM
24-29
COMPRESSOR
SERVICE
(SD-709)
24-21 DIAGNOSTIC PROCEDURES 24-3
GENERAL INFORMATION 24-1 REFRIGERANT SYSTEM SERVICE PROCEDURES . . 24-17
TORQUE SPECIFICATIONS
24-39
HORNS 8G-1
SERVICE
PROCEDURES 8G-3
TEST PROCEDURES 8G-1
IGNITION
SYSTEMS
8D-1 COMPONENT IDENTIFICATION/SYSTEM OPERATION. 8D-1
COMPONENT REMOVAL/INSTALLATION 8D-18 DIAGNOSTICS/SERVICE PROCEDURES 8D-7
IGNITION
SWITCH
8D-25
SPECIFICATIONS
8D-28
INSTRUMENT PANEL AND GAUGES 8E-1

CLUSTER
AND
GAUGE SERVICE PROCEDURES
. . . 8E-12
CLUSTER
AND
GAUGE TEST PROCEDURES
8E-5
GENERAL INFORMATION
8E-1
MESSAGE
CENTER-DIESEL ENGINE
8E-4
MESSAGE
CENTER-GAS ENGINE
8E-3
SWITCH
AND
PANEL COMPONENT SERVICE
8E-16
INTRODUCTION
lntro.-1
DESIGNATIONS, LABELS/PLATES/DECALS, CODES AND DIMENSIONS/WEIGHTS
Intro.-1
MEASUREMENT
AND
TORQUE SPECIFICATIONS
lntro.-11
LAMPS
8L-1
BULB APPLICATION
8L-11
EXTERIOR LAMPS
8L-1
EXTERIOR LAMPS SERVICE PROCEDURES
8L-3
INTERIOR LAMPS
8L-10
LUBRICATION
AND
MAINTENANCE
0-1
CHASSIS
AND
BODY
0-28
DRIVETRAIN
0-22
ENGINE MAINTENANCE
0-14
GENERAL INFORMATION
0-1
POWER DOOR LOCKS
8P-1
SERVICE
PROCEDURES
8P-2
TEST PROCEDURES
8P-1
POWER MIRRORS
8T-1
SERVICE
PROCEDURES
8T-2
TEST PROCEDURES
8T-1
POWER WINDOWS
8S-1
SERVICE
PROCEDURES
8S-3
TEST PROCEDURES
8S-1
PROPELLER SHAFTS
16-1
GENERAL INFORMATION
16-1
PROPELLER SHAFT REPLACEMENT
16-8
SERVICE
DIAGNOSIS/PROCEDURES
16-3
TORQUE SPECIFICATIONS
16-15
UNIVERSAL
JOINT
REPLACEMENT
16-10
REAR
SUSPENSION
AND
AXLE
3-1
8
3/8 and 9 1/4
AXLE
3-11
GENERAL INFORMATION
3-1
MODEL
60 and 70
AXLES
3-29
POWER-LOK DIFFERENTIAL
3-55
REAR
SUSPENSION—2WD
and 4WD
VEHICLES
.... 3-3
SERVICE
DIAGNOSIS
3-6
SPECIFICATIONS
3-27
SURE-GRIP
DIFFERENTIAL SERVICE
3-28
TORQUE SPECIFICATIONS
3-59
TRAC-LOK DIFFERENTIAL
3-51
REAR
WINDOW DEFOGGER
8N-1
REPAIR PROCEDURES (GRID LINES, TERMINALS,
AND PIGTAILS)
8N-3
SERVICE
PROCEDURES
8N-4
TEST PROCEDURES
8N-1
STEERING
19-1
GENERAL INFORMATION
19-1
POWER STEERING PUMP
19-11
POWER STEERING SYSTEM DIAGNOSIS
19-2
RECIRCULATING BALL POWER STEERING GEAR
. . 19-20
STEERING COLUMN
19-35
STEERING LINKAGE
19-17
TORQUE SPECIFICATIONS
19-40
TRANSMISSION
AND
TRANSFER CASE
21-1
AUTOMATIC TRANSMISSION DIAGNOSIS
AND
TESTING
21-85
AUTOMATIC TRANSMISSION REMOVAL
AND
INSTALLATION
21-142
AUTOMATIC TRANSMISSION—32RH/36RH/37RH/
42RH/46RH
21-73
G360
MANUAL TRANSMISSION
21-46
G360
TRANSMISSION OVERHAUL
21-53
GENERAL INFORMATION-32RH/36RH/37RH
21-73
GENERAL INFORMATION—42RH/46RH
. . . 21-78
IN-VEHICLE SERVICE—32RH/36RH/37RH/ 42RH/46RH
21-130
NP205
TRANSFER CASE
21-342
NP241
TRANSFER CASE
21-350
NV4500
MANUAL TRANSMISSION
21-1
NV4500
TRANSMISSION OVERHAUL
21-6
OVERDRIVE
UNIT
OVERHAUL—42RH/46RH
21-324
TRANSMISSION OVERHAUL—32RH
21-152
TRANSMISSION OVERHAUL—36RH/37RH
21-192
TRANSMISSION OVERHAUL—42RH
21-233
TRANSMISSION OVERHAUL—46RH
21-278
TRANSMISSION/TRANSFER CASE SPECIFICATIONS
21-364
TURN SIGNALS
AND
HAZARD WARNING FLASHER
. . . 8J-1
GENERAL INFORMATION
8J-1
MULTIFUNCTION SWITCH SERVICE PROCEDURES.
. 8J-3
MULTIFUNCTION SWITCH TESTING PROCEDURES.
. 8J-2
VEHICLE
SPEED
CONTROL SYSTEM
8H-1
SERVICE
PROCEDURES
8H-11
TEST PROCEDURES
8H-7
WHEELS
AND
TIRES
22-1
TIRES
22-1
TORQUE SPECIFICATIONS
22-13
VEHICLE VIBRATION
22-11
WHEELS
22-6
WINDSHIELD WIPER
AND
WASHER
SYSTEMS
8K-1
INTERMITTENT WINDSHIELD WIPER FUNCTION
AND
SWITCH TESTING PROCEDURES
8K-6
TWO
SPEED
WINDSHIELD WIPER MOTOR
AND
SWITCH TESTING PROCEDURES
8K-1
WINDSHIELD WASHERS
8K-10
WINDSHIELD WIPER SYSTEM SERVICE
PROCEDURES
8K-7
WIRING DIAGRAMS
8W-1
COMPONENT IDENTIFICATION
8W-9
GENERAL INFORMATION
8W-1
SPLICE
LOCATIONS
8W-29
WIRING DIAGRAMS AD-BODY
8W-37