Speed control DODGE RAM 1500 1998 2.G Workshop Manual

BLOWER MOTOR SWITCH
DESCRIPTION
The blower motor is controlled by a rotary-type
blower motor switch, mounted in the A/C-heater con-
trol. The switch allows the selection of one of four
different blower motor speeds and includes an Off
position.
OPERATION
The blower motor switch provides a blower motor
ground path through the A/C-heater mode control
switch. The blower motor switch directs this ground
path through or around the blower motor resistor
wires, as required to achieve the selected blower
motor speed.
The blower motor switch cannot be repaired and, if
faulty or damaged, the entire A/C-heater control
must be replaced.
DIAGNOSIS AND TESTING - BLOWER MOTOR
SWITCH
For circuit descriptions and diagrams, refer to the
appropriate wiring information. The wiring informa-
tion includes wiring diagrams, proper wire and con-
nector repair procedures, further details on wire
harness routing and retention, as well as pin-out and
location views for the various wire harness connec-
tors, splices and grounds.
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) Check for battery voltage at the fuse in the
Power Distribution Center (PDC). If OK, go to Step
2. If not OK, repair the shorted circuit or component
as required and replace the faulty fuse.
(2) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Remove the A/C-heater control from the instrument
panel (Refer to 24 - HEATING & AIR CONDITION-
ING/CONTROLS/A/C HEATER CONTROL -
REMOVAL). Check for continuity between the
ground circuit cavity of the A/C-heater control wire
harness connector and a good ground. There should
be continuity. If OK, go to Step 3. If not OK, repair
the open circuit to ground as required.
(3) With the A/C-heater control wire harness con-
nector disconnected, place the A/C-heater mode con-
trol switch in any position except the Off position.
Check for continuity between the ground circuit ter-
minal and each of the blower motor driver circuit ter-
minals of the A/C-heater control as you move the
blower motor switch to each of the four speed posi-
tions. There should be continuity at each driver cir-
cuit terminal in only one blower motor switch speed
position. If OK, test and repair the blower driver cir-
cuits between the A/C-heater control connector and
the blower motor resistor as required. If not OK,
replace the faulty A/C-heater control.
DEFROST DOOR ACTUATOR
DESCRIPTION
The defrost door actuator is a reversible, 12-volt
Direct Current (DC), servo motor. The defrost door
actuator is located on the driver side end of the
HVAC housing, underneath the instrument panel
and is mechanically connected to the defroster door.
The defrost door actuator is interchangeable with
the actuators for the mode door, blend door(s) and
the recirculation door. Each actuator is contained
within an identical black molded plastic housing with
an integral wire connector receptacle. Integral
mounting tabs allow the actuator to be secured with
three screws to the HVAC housing. Each actuator
also has an identical output shaft with splines that
connects it to the linkage that drives the proper door.
The defrost door actuator does not require mechani-
Fig. 18 A/C-Heater Control - Single Zone Shown,
Dual Zone Typical
1 - MOUNTING TAB (4)
2 - A/C BUTTON
3 - SIDEVIEW MIRROR DEFROSTER BUTTON (IF EQUIPED)
4 - MODE CONTROL SWITCH
5 - TEMPERATURE CONTROL SWITCH
6 - BLOWER MOTOR SWITCH
24 - 20 CONTROLSDR

(5) Install the HVAC housing (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION/HVAC
HOUSING - INSTALLATION)
BLOWER MOTOR
DESCRIPTION
The blower motor and blower wheel are located in
the passenger side end of the HVAC housing, below
the glove box. The blower motor controls the velocity
of air flowing through the HVAC housing by spinning
a squirrel cage-type blower wheel within the housing
at the selected speed. The blower motor and wheel
can be removed from the housing inside the vehicle
without removing the instrument panel or HVAC
housing.
OPERATION
The blower motor will only operate with the igni-
tion switch in the On position and the A/C-heater
mode control switch in any position, except Off. The
blower motor receives a fused battery feed circuit
through a fuse in the Power Distribution Center
(PDC) whenever the ignition switch is in the On posi-
tion. Blower motor speed is controlled by regulating
the ground path through or around the blower motor
resistor block and through the A/C-heater blower
motor switch.
The blower motor and blower motor wheel are ser-
viced only as a unit and cannot be repaired and, if
faulty or damaged, must be replaced.
DIAGNOSIS AND TESTING - BLOWER MOTOR
BLOWER MOTOR INOPERATIVE
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 ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
For circuit descriptions and diagrams, refer to the
appropriate wiring information. The wiring informa-
tion includes wiring, diagrams, proper wire and con-
nector repair procedures, further details on wire
harness routing and retention, as well as pin-out and
location views for the various wire harness connec-
tors, splices and grounds.
BLOWER MOTOR ELECTRICAL DIAGNOSIS
Refer to the Blower Motor Electrical Diagnosis
chart for basic checks of the blower motor circuit
(Fig. 3).
BLOWER MOTOR NOISE OR VIBRATION
Refer to the Blower Motor Noise/Vibration Diagno-
sis chart for basic checks of the blower motor when a
vibration or noise is present (Fig. 4).
24 - 28 DISTRIBUTIONDR
BLEND DOOR (Continued)

After the system has been tested for leaks and
evacuated, a refrigerant (R-134a) charge can be
injected into the system.
NOTE: When connecting the service equipment
coupling to the line fitting, verify that the valve of
the coupling is fully closed. This will reduce the
amount of effort required to make the connection.
(1) If using a separate vacuum pump close all
valves before disconnecting pump. Connect manifold
gauge set to the A/C service ports.
NOTE: Always refer to the underhood HVAC Speci-
fication label for the refrigerant fill level of the vehi-
cle being serviced.
(2) Measure refrigerant (refer to capacities). Refer
to the instructions provided with the equipment
being used.
(3) Verify engine is shut off. Open the suction and
discharge valves. Open the charge valve to allow the
refrigerant to flow into the system. When the trans-
fer of refrigerant has stopped, close the suction and
discharge valve.
(4) If all of the charge did not transfer from the
dispensing device, put vehicle controls into the fol-
lowing mode:
²Automatic transmission in park or manual
transmission in neutral
²Engine at idle
²A/C mode control set to outside air
²A/C mode control set to panel mode
²A/C temperature control set to full cool
²Blower motor control set on highest speed
²Vehicle windows closed
If the A/C compressor does not engage, test the
compressor clutch control circuit and correct any fail-
ure (Refer to 8 - ELECTRICAL/WIRING DIAGRAM
INFORMATION - DIAGNOSIS AND TESTING).
(5) Open the suction valve to allow the remaining
refrigerant to transfer to the system.
WARNING: TAKE CARE NOT TO OPEN THE DIS-
CHARGE (HIGH-PRESSURE) VALVE AT THIS TIME.
(6) Close all valves and test the A/C system perfor-
mance.
(7) Disconnect the charging station or manifold
gauge set. Install the service port caps.
REFRIGERANT CHARGE CAPACITY
The R-134a refrigerant system charge capacity for
this vehicle can be found on the underhood HVAC
specfication tag.
A/C COMPRESSOR
DESCRIPTION
DESCRIPTION - A/C COMPRESSOR
The A/C system on models equipped with the 5.9L
engine use a Sanden SD-7 reciprocating swash plate-
type compressor. This compressor has a fixed dis-
placement of 165 cubic centimeter (10.068 cubic
inches) and has both the suction and discharge ports
located on the cylinder head.
The A/C system on models equipped with the 3.7L,
4.7L and 5.7L engines use a Denso 10S17 reciprocat-
ing swash plate-type compressor. This compressor
has a fixed displacement of 170 cubic centimeter and
has both the suction and discharge ports located on
the cylinder head.
A label identifying the use of R-134a refrigerant is
located on both A/C compressors.
DESCRIPTION - HIGH PRESSURE RELIEF
VALVE
A high pressure relief valve is located on the com-
pressor cylinder head, which is on the rear of the
compressor. This mechanical valve is designed to
vent refrigerant from the system to protect against
damage to the compressor and other system compo-
nents, caused by condenser air flow restriction or an
overcharge of refrigerant.
OPERATION
OPERATION - A/C COMPRESSOR
The A/C compressor is driven by the engine
through an electric clutch, drive pulley and belt
arrangement. The compressor is lubricated by refrig-
erant oil that is circulated throughout the refrigerant
system with the refrigerant.
The compressor draws in low-pressure refrigerant
vapor from the evaporator through its suction port. It
then compresses the refrigerant into a high-pressure,
high-temperature refrigerant vapor, which is then
pumped to the condenser through the compressor dis-
charge port.
The compressor cannot be repaired. If faulty or
damaged, the entire compressor assembly must be
replaced. The compressor clutch, pulley and clutch
coil are available for service.
OPERATION - HIGH PRESSURE RELIEF VALVE
The high pressure relief valve vents the system
when a discharge pressure of 3445 to 4135 kPa (500
to 600 psi) or above is reached. The valve closes
24 - 48 PLUMBINGDR
PLUMBING (Continued)

when a minimum discharge pressure of 2756 kPa
(400 psi) is reached.
The high pressure relief valve vents only enough
refrigerant to reduce the system pressure, and then
re-seats itself. The majority of the refrigerant is con-
served in the system. If the valve vents refrigerant, it
does not mean that the valve is faulty.
The high pressure relief valve is a factory-cali-
brated unit. The valve cannot be adjusted or
repaired, and must not be removed or otherwise dis-
turbed. The valve is only serviced as a part of the
compressor assembly.
DIAGNOSIS AND TESTING - A/C COMPRESSOR
When investigating an air conditioning related
noise, you must first know the conditions under
which the noise occurs. These conditions include:
weather, vehicle speed, transmission in gear or neu-
tral, engine speed, engine temperature, and any
other special conditions. Noises that develop during
air conditioning operation can often be misleading.
For example: What sounds like a failed front bearing
or connecting rod, may be caused by loose bolts, nuts,
mounting brackets, or a loose compressor clutch
assembly.
Drive belts are speed sensitive. At different engine
speeds and depending upon belt tension, belts can
develop noises that are mistaken for a compressor
noise. Improper belt tension can cause a misleading
noise when the compressor clutch is engaged, which
may not occur when the compressor clutch is disen-
gaged. Check the serpentine drive belt condition and
tension as described in Cooling before beginning this
procedure.
(1) Select a quiet area for testing. Duplicate the
complaint conditions as much as possible. Switch the
compressor on and off several times to clearly iden-
tify the compressor noise. Listen to the compressor
while the clutch is engaged and disengaged. Probe
the compressor with an engine stethoscope or a long
screwdriver with the handle held to your ear to bet-
ter localize the source of the noise.
(2) Loosen all of the compressor mounting hard-
ware and retighten. Tighten the compressor clutch
mounting nut. Be certain that the clutch coil is
mounted securely to the compressor, and that the
clutch plate and rotor are properly aligned and have
the correct air gap (Refer to 24 - HEATING & AIR
CONDITIONING/CONTROLS/A/C COMPRESSOR
CLUTCH - INSTALLATION).
(3) To duplicate a high-ambient temperature condi-
tion (high head pressure), restrict the air flow
through the condenser. Install a manifold gauge set
or a DRBIIItscan tool to be certain that the dis-
charge pressure does not exceed 2760 kPa (400 psi).(4) Check the refrigerant system plumbing for
incorrect routing, rubbing or interference, which can
cause unusual noises. Also check the refrigerant lines
for kinks or sharp bends that will restrict refrigerant
flow, which can cause noises (Refer to 24 - HEATING
& AIR CONDITIONING/PLUMBING - STANDARD
PROCEDURE).
(5) If the noise is from opening and closing of the
high pressure relief valve, recover, evacuate and
recharge the refrigerant system (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - STAN-
DARD PROCEDURE), (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - STANDARD
PROCEDURE - REFRIGERANT SYSTEM EVACU-
ATE) and (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT SYSTEM CHARGE). If the high
pressure relief valve still does not seat properly,
replace the compressor (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING/A/C COMPRES-
SOR - REMOVAL).
(6) If the noise is from liquid slugging on the suc-
tion line, replace the accumulator (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/AC-
CUMULATOR - REMOVAL) and check the refriger-
ant oil level and the refrigerant system charge (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMB-
ING/REFRIGERANT OIL - STANDARD PROCE-
DURE) (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING/ACCUMULATOR -
REMOVAL). If after replacing the accumulator the
slugging condition still exists then replace the com-
pressor.(Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING/A/C COMPRESSOR - REMOVAL).
(7) If the liquid slugging condition continues fol-
lowing accumulator replacement, replace the com-
pressor and repeat Step 1.
REMOVAL
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
WARNING) and (Refer to 24 - HEATING & AIR CON-
DITIONING/PLUMBING - CAUTION).
NOTE: The A/C compressor may be removed and
repositioned without disconnecting the refrigerant
lines or discharging the refrigerant system. Dis-
charging is not necessary if servicing the compres-
sor clutch, clutch coil, engine, engine cylinder head
or the generator.
(1) Recover the refrigerant from the refrigerant
system (Refer to 24 - HEATING & AIR CONDITION-
DRPLUMBING 24 - 49
A/C COMPRESSOR (Continued)

(12) Reconnect the battery negative cable.
(13) Evacuate the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE).
(14) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE).
HEATER CORE
DESCRIPTION
The heater core is located in the HVAC housing,
behind the instrument panel. It is a heat exchanger
made of rows of tubes and fins.
OPERATION
Engine coolant is circulated through the heater
hoses to the heater core at all times. As the coolant
flows through the heater core, heat is removed from
the engine and is transferred to the heater core fins
and tubes. Air directed through the heater core picks
up the heat from the heater core fins. The blend door
allows control of the heater output air temperature
by regulating the amount of air flowing through the
heater core within the HVAC housing. The blower
motor speed controls the volume of air flowing
through the HVAC housing.
The heater core cannot be repaired and, if faulty or
damaged, it must be replaced.
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 ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
NOTE: Disassembly of the HVAC housing is not
required to remove heater core.
(1) Remove the HVAC housing (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - REMOVAL).(2) Remove the foam seal from the heater core
tubes.
(3) If equipped with the Dual Zone system, remove
the linkage rod from the actuator levers to gain
access to the heater core (Fig. 23).
(4) Remove the two screws that secure the heater
core tube bracket to the HVAC housing.
(5) Remove the heater core tube bracket.
(6) Pull the heater core out of the HVAC housing.
(7) Inspect all foam seals and repair or replace
them as required.
INSTALLATION
(1) Install the heater core into the HVAC housing.
(2) Position the heater core tube bracket onto the
HVAC housing.
(3) Install the two screws that secure the heater
core bracket to the HVAC housing. Tighten the
screws to 2.2 N´m (20 in. lbs.).
(4) If equipped with the Dual Zone system, install
the linkage rod onto the actuator levers.
(5) Install the foam seal onto the heater core
tubes.
(6) Install the HVAC housing (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION/HVAC
HOUSING - INSTALLATION).
Fig. 23 Heater Core ± Dual Zone Shown, Single
Zone Typical
1 - SCREWS
2 - TUBE BRACKET
3 - HEATER CORE
4 - LINKAGE ROD (IF EQUIPPED)
DRPLUMBING 24 - 63
ACCUMULATOR (Continued)

Immediately after a cold start, between predeter-
mined temperature thresholds limits, the three port
solenoid is briefly energized. This initializes the
pump by drawing air into the pump cavity and also
closes the vent seal. During non test conditions the
vent seal is held open by the pump diaphragm
assembly which pushes it open at the full travel posi-
tion. The vent seal will remain closed while the
pump is cycling due to the reed switch triggering of
the three port solenoid that prevents the diaphragm
assembly from reaching full travel. After the brief
initialization period, the solenoid is de-energized
allowing atmospheric pressure to enter the pump
cavity, thus permitting the spring to drive the dia-
phragm which forces air out of the pump cavity and
into the vent system. When the solenoid is energized
and de energized, the cycle is repeated creating flow
in typical diaphragm pump fashion. The pump is con-
trolled in 2 modes:
Pump Mode: The pump is cycled at a fixed rate to
achieve a rapid pressure build in order to shorten the
overall test length.
Test Mode: The solenoid is energized with a fixed
duration pulse. Subsequent fixed pulses occur when
the diaphragm reaches the Switch closure point.
The spring in the pump is set so that the system
will achieve an equalized pressure of about 7.5º H20.
The cycle rate of pump strokes is quite rapid as the
system begins to pump up to this pressure. As the
pressure increases, the cycle rate starts to drop off. If
there is no leak in the system, the pump would even-
tually stop pumping at the equalized pressure. If
there is a leak, it will continue to pump at a rate rep-
resentative of the flow characteristic of the size of the
leak. From this information we can determine if the
leak is larger than the required detection limit (cur-
rently set at .040º orifice by CARB). If a leak is
revealed during the leak test portion of the test, the
test is terminated at the end of the test mode and no
further system checks will be performed.
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, indicatedby 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. 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
DREMISSIONS CONTROL 25 - 3
EMISSIONS CONTROL (Continued)

OPERATION
OPERATION
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-
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. The connector is
located on the bottom edge of the instrument panel
near the steering column (Fig. 1).
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 - 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 TaskManager software organizes and prioritizes the diag-
nostic procedures. The job of the Task Manager is to
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.
Fig. 1 DATA LINK CONNECTOR LOCATION - TYPICAL
1 - 16-WAY DATA LINK CONNECTOR
DREMISSIONS CONTROL 25 - 5
EMISSIONS CONTROL (Continued)

FRONT SERVO - DESCRIPTION.........21-208
FRONT SERVO - DISASSEMBLY........21-209
FRONT SERVO - INSPECTION..........21-209
FRONT SERVO - OPERATION..........21-208
FRONT SKID PLATE - INSTALLATION.....13-23
FRONT SKID PLATE - REMOVAL.........13-23
FRONT SUSPENSION - DESCRIPTION,
GEAR - INDEPENDENT................19-17
FRONT SUSPENSION - INSTALLATION,
GEAR - INDEPENDENT................19-18
FRONT SUSPENSION - REMOVAL, GEAR
- INDEPENDENT.....................19-17
FRONT SUSPENSION, SPECIAL TOOLS....2-12
FRONT TOW HOOK ASSEMBLY -
INSTALLATION.......................13-23
FRONT TOW HOOK ASSEMBLY -
REMOVAL..........................13-23
FRONT WHEEL SPEED SENSOR -
DESCRIPTION........................5-47
FRONT WHEEL SPEED SENSOR -
INSTALLATION........................5-48
FRONT WHEEL SPEED SENSOR -
OPERATION..........................5-47
FRONT WHEEL SPEED SENSOR -
REMOVAL...........................5-48
FRONT WHEELHOUSE SPLASH SHIELD -
INSTALLATION.......................23-41
FRONT WHEELHOUSE SPLASH SHIELD -
REMOVAL..........................23-41
FUEL CONTROL ACTUATOR -
DESCRIPTION.......................14-74
FUEL CONTROL ACTUATOR -
OPERATION.........................14-74
FUEL CONTROL ACTUATOR - REMOVAL . . . 14-74
FUEL DELIVERY - GAS - DESCRIPTION....14-1
FUEL DELIVERY - GAS - OPERATION......14-2
FUEL DRAIN CIRCUIT - OPERATION......14-67
FUEL FILL DOOR - INSTALLATION.......23-39
FUEL FILL DOOR - REMOVAL...........23-39
FUEL FILLER CAP - DESCRIPTION.......25-13
FUEL FILLER CAP - OPERATION.........25-13
FUEL FILTER - STANDARD
PROCEDURES, WATER DRAINING AT.....14-47
FUEL FILTER / WATER SEPARATOR -
DESCRIPTION.......................14-50
FUEL FILTER / WATER SEPARATOR -
INSTALLATION.......................14-50
FUEL FILTER / WATER SEPARATOR -
OPERATION.........................14-50
FUEL FILTER / WATER SEPARATOR -
REMOVAL..........................14-50
FUEL FILTER/PRESSURE REGULATOR -
DESCRIPTION........................14-5
FUEL FILTER/PRESSURE REGULATOR -
OPERATION..........................14-6
FUEL GAUGE - DESCRIPTION...........8J-26
FUEL GAUGE - OPERATION.............8J-26
FUEL HEATER - DESCRIPTION..........14-51
FUEL HEATER - DIAGNOSIS AND
TESTING...........................14-52
FUEL HEATER - OPERATION............14-51
FUEL HEATER RELAY - DESCRIPTION....14-52
FUEL HEATER RELAY - INSTALLATION....14-53
FUEL HEATER RELAY - OPERATION......14-52
FUEL HEATER RELAY - REMOVAL........14-52
FUEL INDICATOR - DESCRIPTION, LOW . . . 8J-30
FUEL INDICATOR - OPERATION, LOW.....8J-30
FUEL INJECTION PUMP - DESCRIPTION . . 14-53
FUEL INJECTION PUMP - INSTALLATION . . 14-55
FUEL INJECTION PUMP - OPERATION....14-53
FUEL INJECTION PUMP - REMOVAL......14-54
FUEL INJECTION PUMP TIMING -
DIAGNOSIS AND TESTING.............14-53
FUEL INJECTOR - DESCRIPTION....14-26,14-74
FUEL INJECTOR - INSTALLATION........14-77
FUEL INJECTOR - OPERATION.....14-26,14-74
FUEL INJECTOR - REMOVAL............14-75
FUEL INJECTOR FIRING ORDER, DIESEL . . 14-48
FUEL INJECTOR RAIL - DESCRIPTION....14-78
FUEL INJECTOR RAIL - INSTALLATION....14-78
FUEL INJECTOR RAIL - OPERATION
......14-78
FUEL INJECTOR RAIL - REMOVAL
.......14-78
FUEL LEVEL SENDING UNIT / SENSOR -
DESCRIPTION
...................14-57,14-6
FUEL LEVEL SENDING UNIT / SENSOR -
INSTALLATION
........................14-7
FUEL LEVEL SENDING UNIT / SENSOR -
OPERATION
.....................14-57,14-6FUEL LEVEL SENDING UNIT / SENSOR -
REMOVAL...........................14-7
FUEL LINE LEAKS - DIAGNOSIS AND
TESTING, HIGH-PRESSURE.............14-58
FUEL LINES - DESCRIPTION........14-57,14-7
FUEL LINES - INSTALLATION...........14-60
FUEL LINES - OPERATION..............14-57
FUEL LINES - REMOVAL...............14-58
FUEL PRESSURE LIMITING VALVE -
DESCRIPTION.......................14-61
FUEL PRESSURE LIMITING VALVE -
INSTALLATION.......................14-61
FUEL PRESSURE LIMITING VALVE -
OPERATION.........................14-61
FUEL PRESSURE LIMITING VALVE -
REMOVAL..........................14-61
FUEL PRESSURE SENSOR -
DESCRIPTION.......................14-60
FUEL PRESSURE SENSOR -
INSTALLATION.......................14-61
FUEL PRESSURE SENSOR - OPERATION . . 14-60
FUEL PRESSURE SENSOR - REMOVAL....14-60
FUEL PUMP - DESCRIPTION............14-11
FUEL PUMP - OPERATION.............14-11
FUEL PUMP MODULE - DESCRIPTION....14-11
FUEL PUMP MODULE - INSTALLATION . . . 14-12
FUEL PUMP MODULE - OPERATION......14-11
FUEL PUMP MODULE - REMOVAL.......14-12
FUEL PUMP RELAY - DESCRIPTION......14-27
FUEL PUMP RELAY - INSTALLATION.....14-28
FUEL PUMP RELAY - OPERATION........14-27
FUEL PUMP RELAY - REMOVAL.........14-28
FUEL PUMP RELAYS - DIAGNOSIS AND
TESTING, ASD........................8I-5
FUEL RAIL - DESCRIPTION.............14-12
FUEL RAIL - INSTALLATION............14-15
FUEL RAIL - OPERATION...............14-12
FUEL RAIL - REMOVAL................14-13
FUEL REQUIREMENTS - DIESEL ENGINE
- DESCRIPTION........................0-1
FUEL SENSOR - DESCRIPTION, WATER
IN ................................14-66
FUEL SENSOR - OPERATION, WATER IN . . 14-66
FUEL SENSOR - REMOVAL, WATER IN....14-66
FUEL SYSTEM - DESCRIPTION, DIESEL . . . 14-45
FUEL SYSTEM - DIESEL ENGINE -
TORQUE............................14-48
FUEL SYSTEM - EXCEPT DIESEL -
TORQUE............................14-3
FUEL SYSTEM PARTS - STANDARD
PROCEDURES, CLEANING..............14-47
FUEL SYSTEM PRESSURE RELEASE -
STANDARD PROCEDURE................14-2
FUEL SYSTEM PRESSURE,
SPECIFICATIONS......................14-3
FUEL SYSTEM PRIMING - STANDARD
PROCEDURE........................14-47
FUEL SYSTEM, SPECIAL TOOLS..........14-5
FUEL SYSTEM, SPECIAL TOOLS -
DIESEL............................14-49
FUEL TANK - DESCRIPTION............14-17
FUEL TANK - OPERATION..............14-17
FUEL TANK MODULE - DESCRIPTION.....14-63
FUEL TANK MODULE - INSTALLATION....14-64
FUEL TANK MODULE - OPERATION......14-63
FUEL TANK MODULE - REMOVAL........14-63
FUEL TRANSFER PUMP - DESCRIPTION . . 14-64
FUEL TRANSFER PUMP - INSTALLATION . . 14-65
FUEL TRANSFER PUMP - OPERATION....14-64
FUEL TRANSFER PUMP - REMOVAL......14-64
FULL SIZE, SPARE WHEEL WITH
MATCHING TIRE - DESCRIPTION........22-15
FUNCTIONS - DESCRIPTION, CIRCUIT . . 8W-01-6
FUSE - DESCRIPTION, IOD...........8W-97-6
FUSE - INSTALLATION, IOD..........8W-97-7
FUSE - OPERATION, IOD.............8W-97-6
FUSE - REMOVAL, IOD..............8W-97-7
FUSES POWERING SEVERAL LOADS -
STANDARD PROCEDURE, TESTING
FOR A SHORT TO GROUND ON......8W-01-10
GAP AND FLUSH - SPECIFICATIONS......23-95
GAS ENGINE - DIAGNOSIS AND TESTING
. . 11-4
GAS ENGINE - INSTALLATION
...........19-26
GAS ENGINE - REMOVAL
..............19-25
GAS ENGINES - CLEANING, RADIATOR
FAN
................................7-34
GAS ENGINES - DESCRIPTION, COOLANT
RECOVERY CONTAINER
................7-33GAS ENGINES - INSPECTION, RADIATOR
FAN ................................7-34
GAS ENGINES - INSTALLATION,
COOLANT RECOVERY CONTAINER........7-33
GAS ENGINES - INSTALLATION,
RADIATOR FAN.......................7-34
GAS ENGINES - OPERATION, COOLANT
RECOVERY CONTAINER................7-33
GAS ENGINES - REMOVAL, COOLANT
RECOVERY CONTAINER................7-33
GAS ENGINES - REMOVAL, RADIATOR
FAN ................................7-33
GAS ENGINES - STANDARD
PROCEDURE, DRAINING COOLING
SYSTEM - ALL........................7-17
GAS ENGINES - STANDARD
PROCEDURE, REFILLING COOLING
SYSTEM - ALL........................7-18
GASKET - DIAGNOSIS AND TESTING,
CYLINDER HEAD......................9-21
GASKET FAILURE - DIAGNOSIS AND
TESTING, CYLINDER HEAD.............9-199
GASKET SELECTION - STANDARD
PROCEDURE, HEAD...................9-281
GASKET SURFACE PREPARATION -
STANDARD PROCEDURE, ENGINE........9-10
GASKETS AND SEALERS - STANDARD
PROCEDURE, FORM-IN-PLACE . . . 9-239,9-9,9-94
GAUGE - DESCRIPTION, ENGINE
TEMPERATURE......................8J-24
GAUGE - DESCRIPTION, FUEL...........8J-26
GAUGE - DESCRIPTION, OIL PRESSURE . . 8J-33
GAUGE - DESCRIPTION, VOLTAGE.......8J-42
GAUGE - OPERATION, ENGINE
TEMPERATURE......................8J-24
GAUGE - OPERATION, FUEL............8J-26
GAUGE - OPERATION, OIL PRESSURE....8J-33
GAUGE - OPERATION, VOLTAGE.........8J-43
GAUGES - DIAGNOSIS AND TESTING,
PRESSURE..........................22-7
GAUGES INDICATOR - DESCRIPTION,
CHECK.............................8J-21
GAUGES INDICATOR - OPERATION,
CHECK.............................8J-21
GEAR - DESCRIPTION, CRANKSHAFT.....9-273
GEAR - INDEPENDENT FRONT
SUSPENSION - DESCRIPTION...........19-17
GEAR - INDEPENDENT FRONT
SUSPENSION - INSTALLATION..........19-18
GEAR - INDEPENDENT FRONT
SUSPENSION - REMOVAL..............19-17
GEAR - INSTALLATION................9-273
GEAR - INSTALLATION, PINION
GEAR/RING......................3-51,3-77
GEAR - LINK/COIL - DESCRIPTION.......19-20
GEAR - LINK/COIL - INSTALLATION......19-21
GEAR - LINK/COIL - OPERATION........19-20
GEAR - LINK/COIL - REMOVAL..........19-20
GEAR - REMOVAL....................9-273
GEAR - REMOVAL, PINION GEAR/RING....3-49,
3-75
GEAR HOUSING - INSTALLATION........9-300
GEAR HOUSING - REMOVAL............9-299
GEAR HOUSING COVER - INSTALLATION . . 9-301
GEAR HOUSING COVER - REMOVAL
.....9-301
GEAR INPUT SHAFT SEAL -
INSTALLATION, STEERING
.............19-29
GEAR INPUT SHAFT SEAL - REMOVAL,
STEERING
..........................19-27
GEAR SELECTOR INDICATOR -
DESCRIPTION
.......................8J-27
GEAR SELECTOR INDICATOR -
OPERATION
.........................8J-27
GEAR SHIFT LEVER - INSTALLATION
.....19-12
GEAR SHIFT LEVER - REMOVAL
.........19-12
GEAR, SPECIAL TOOLS - POWER
STEERING
..........................19-23
GEAR, SPECIFICATIONS - POWER
STEERING
..........................19-22
GEAR TO COOLER - INSTALLATION,
RETURN HOSE
.................19-44,19-45
GEAR TO COOLER - REMOVAL, RETURN
HOSE
.........................19-44,19-45
GEAR/RING GEAR - INSTALLATION,
PINION
.........................3-51,3-77
GEAR/RING GEAR - REMOVAL, PINION
....3-49,
3-75
14 INDEXDR
Description Group-Page Description Group-Page Description Group-Page

HEATED SEAT MODULE - INSTALLATION . . . 8E-7
HEATED SEAT MODULE - INSTALLATION . . 8G-15
HEATED SEAT MODULE - OPERATION.....8E-6
HEATED SEAT MODULE - OPERATION....8G-14
HEATED SEAT MODULE - REMOVAL.......8E-7
HEATED SEAT MODULE - REMOVAL.....8G-15
HEATED SEAT SENSOR - DESCRIPTION . . . 8G-11
HEATED SEAT SENSOR - DIAGNOSIS
AND TESTING.......................8G-11
HEATED SEAT SENSOR - OPERATION....8G-11
HEATED SEAT SENSOR - REMOVAL......8G-11
HEATED SEAT SWITCH - DESCRIPTION . . . 8G-11
HEATED SEAT SWITCH - DIAGNOSIS
AND TESTING.......................8G-12
HEATED SEAT SWITCH - INSTALLATION . . 8G-13
HEATED SEAT SWITCH - OPERATION.....8G-12
HEATED SEAT SWITCH - REMOVAL......8G-13
HEATED SEAT SYSTEM - DESCRIPTION....8G-7
HEATED SEAT SYSTEM - DIAGNOSIS
AND TESTING........................8G-8
HEATED SEAT SYSTEM - OPERATION.....8G-8
HEATER - 5.9L DIESEL - DESCRIPTION,
ENGINE BLOCK.......................7-37
HEATER - 5.9L DIESEL - INSTALLATION,
ENGINE BLOCK.......................7-38
HEATER - 5.9L DIESEL - OPERATION,
ENGINE BLOCK.......................7-38
HEATER - 5.9L DIESEL - REMOVAL,
ENGINE BLOCK.........................7-38
HEATER - DESCRIPTION, ENGINE BLOCK . . . 7-36
HEATER - DESCRIPTION, FUEL..........14-51
HEATER - DESCRIPTION, INTAKE AIR.....14-80
HEATER - DIAGNOSIS AND TESTING,
ENGINE BLOCK.......................7-36
HEATER - DIAGNOSIS AND TESTING,
FUEL..............................14-52
HEATER - INSTALLATION, ENGINE
BLOCK..............................7-37
HEATER - INSTALLATION, INTAKE AIR....14-80
HEATER - OPERATION, ENGINE BLOCK....7-36
HEATER - OPERATION, FUEL............14-51
HEATER - OPERATION, INTAKE AIR......14-80
HEATER - REMOVAL, ENGINE BLOCK......7-37
HEATER - REMOVAL, INTAKE AIR........14-80
HEATER AND AIR CONDITIONER -
DESCRIPTION........................24-1
HEATER AND AIR CONDITIONER -
OPERATION..........................24-1
HEATER CONTROL - DESCRIPTION, A/C . . . 24-14
HEATER CONTROL - INSTALLATION, A/C . . 24-15
HEATER CONTROL - REMOVAL, A/C......24-15
HEATER CORE - DESCRIPTION..........24-63
HEATER CORE - INSTALLATION.........24-63
HEATER CORE - OPERATION............24-63
HEATER CORE - REMOVAL.............24-63
HEATER INLET HOSE - INSTALLATION....24-64
HEATER INLET HOSE - REMOVAL........24-64
HEATER PERFORMANCE TEST -
DIAGNOSIS AND TESTING..............24-6
HEATER RELAY - DESCRIPTION, FUEL....14-52
HEATER RELAY - DESCRIPTION, INTAKE
AIR ...............................14-82
HEATER RELAY - INSTALLATION, FUEL . . . 14-53
HEATER RELAY - INSTALLATION, INTAKE
AIR ...............................14-82
HEATER RELAY - OPERATION, FUEL......14-52
HEATER RELAY - OPERATION, INTAKE
AIR ...............................14-82
HEATER RELAY - REMOVAL, FUEL.......14-52
HEATER RELAY - REMOVAL, INTAKE AIR . . 14-82
HEATER RETURN HOSE - INSTALLATION . . 24-65
HEATER RETURN HOSE - REMOVAL......24-64
HEIGHT ADJUSTMENT - 4WD (LD) -
STANDARD PROCEDURE.................2-3
HEIGHT MEASUREMENT - 4WD (LD) -
STANDARD PROCEDURE.................2-3
HEMI ENGINE - INSTALLATION, 3.7L/4.7L
AND 5.7L......................24-59,24-73
HEMI ENGINE - REMOVAL, 3.7L/4.7L
AND 5.7L......................24-57,24-71
HIGH BEAM INDICATOR - DESCRIPTION
. . 8J-28
HIGH BEAM INDICATOR - OPERATION
....8J-28
HIGH MOUNTED STOP LAMP -
INSTALLATION, CENTER
...............8L-11
HIGH MOUNTED STOP LAMP -
REMOVAL, CENTER
...................8L-11
HIGH MOUNTED STOP LAMP UNIT -
INSTALLATION, CENTER
...............8L-11HIGH MOUNTED STOP LAMP UNIT -
REMOVAL, CENTER...................8L-11
HIGH PRESSURE RELIEF VALVE -
DESCRIPTION.......................24-48
HIGH PRESSURE RELIEF VALVE -
OPERATION.........................24-48
HIGH SPEEDS - DESCRIPTION, TIRE
PRESSURE..........................22-7
HIGH/LOW RELAY - DESCRIPTION,
WIPER.............................8R-20
HIGH/LOW RELAY - DIAGNOSIS AND
TESTING, WIPER.....................8R-21
HIGH/LOW RELAY - INSTALLATION,
WIPER.............................8R-22
HIGH/LOW RELAY - OPERATION, WIPER . . 8R-20
HIGH/LOW RELAY - REMOVAL, WIPER . . . 8R-21
HIGH-PRESSURE FUEL LINE LEAKS -
DIAGNOSIS AND TESTING.............14-58
HINGE - INSTALLATION.....23-16,23-22,23-31,
23-46
HINGE - INSTALLATION, CENTER SEAT
BACK..............................23-79
HINGE - REMOVAL....23-16,23-22,23-31,23-46
HINGE - REMOVAL, CENTER SEAT BACK . . 23-78
HINGE COVER - INSTALLATION, CENTER
SEAT BACK INERTIA..................23-77
HINGE COVER - REMOVAL, CENTER
SEAT BACK INERTIA..................23-77
HITCH - INSTALLATION, TRAILER........13-25
HITCH - REMOVAL, TRAILER...........13-25
HOAT COOLANT - DESCRIPTION..........7-32
HOISTING - STANDARD PROCEDURE......0-20
HOLDDOWN - DESCRIPTION, BATTERY . . . 8F-14
HOLDDOWN - INSTALLATION, BATTERY . . . 8F-14
HOLDDOWN - OPERATION, BATTERY.....8F-14
HOLDDOWN - REMOVAL, BATTERY......8F-14
HOLDER - INSTALLATION, CUP.........23-51
HOLDER - REMOVAL, CUP.............23-51
HOLDING CLUTCHES - DESCRIPTION....21-371
HOLDING CLUTCHES - OPERATION.....21-372
HOLE PLUG - INSTALLATION, CAMSHAFT
CORE..............................9-206
HOLE PLUG - REMOVAL, CAMSHAFT
CORE..............................9-205
HOLE REPAIR - DESCRIPTION,
THREADED........................Intro.-8
HONING - STANDARD PROCEDURE,
CYLINDER BORE.................9-128,9-38
HOOD - INSTALLATION................23-47
HOOD - REMOVAL....................23-46
HOOK - INSTALLATION, COAT...........23-66
HOOK - REMOVAL, COAT..............23-66
HOOK ASSEMBLY - INSTALLATION,
FRONT TOW........................13-23
HOOK ASSEMBLY - REMOVAL, FRONT
TOW ..............................13-23
HORN - DIAGNOSIS AND TESTING.......8H-1
HORN - INSTALLATION.................8H-2
HORN - REMOVAL....................8H-2
HORN SWITCH - DESCRIPTION..........8H-2
HORN SWITCH - DIAGNOSIS AND
TESTING............................8H-2
HORN SYSTEM - DESCRIPTION..........8H-1
HORN SYSTEM - DIAGNOSIS AND
TESTING............................8H-1
HORN SYSTEM - OPERATION............8H-1
HOSE - GEAR TO COOLER -
INSTALLATION, RETURN..........19-44,19-45
HOSE - GEAR TO COOLER - REMOVAL,
RETURN......................19-44,19-45
HOSE - INSTALLATION, FRONT BRAKE.....5-13
HOSE - INSTALLATION, HEATER INLET....24-64
HOSE - INSTALLATION, HEATER RETURN . 24-65
HOSE - INSTALLATION, PRESSURE . 19-44,19-45
HOSE - INSTALLATION, REAR BRAKE......5-12
HOSE - REMOVAL, FRONT..............5-12
HOSE - REMOVAL, HEATER INLET.......24-64
HOSE - REMOVAL, HEATER RETURN.....24-64
HOSE - REMOVAL, PRESSURE.....19-44,19-45
HOSE - REMOVAL, REAR BRAKE
.........5-11
HOSE - RESERVOIR TO COOLER -
INSTALLATION, RETURN
..........19-44,19-45
HOSE - RESERVOIR TO COOLER -
REMOVAL, RETURN
.............19-44,19-45
HOSE ASSEMBLY - INSTALLATION, REAR
TUBE
...............................5-13
HOSE ASSEMBLY - REMOVAL, REAR
TUBE
...............................5-12HOSE CLAMPS - DESCRIPTION...........7-3
HOSE CLAMPS - OPERATION.............7-5
HOSES/TUBES - DESCRIPTION, WASHER . 8R-11
HOSES/TUBES - OPERATION, WASHER . . . 8R-11
HOUSING - ASSEMBLY, HVAC...........24-35
HOUSING - DIAGNOSIS AND TESTING,
CLUTCH..............................6-7
HOUSING - DISASSEMBLY, HVAC........24-35
HOUSING - INSTALLATION, CLUTCH.......6-9
HOUSING - INSTALLATION, GEAR........9-300
HOUSING - INSTALLATION, HVAC........24-36
HOUSING - INSTALLATION, ROCKER.....9-255
HOUSING - REMOVAL, CLUTCH...........6-9
HOUSING - REMOVAL, GEAR...........9-299
HOUSING - REMOVAL, HVAC...........24-34
HOUSING - REMOVAL, ROCKER.........9-255
HOUSING BUSHING AND SEAL -
INSTALLATION, EXTENSION...........21-440
HOUSING BUSHING AND SEAL -
REMOVAL, EXTENSION...............21-440
HOUSING COVER - INSTALLATION, GEAR . 9-301
HOUSING COVER - REMOVAL, GEAR.....9-301
HOUSING FLUID LEAK - DIAGNOSIS AND
TESTING, CONVERTER.........21-144,21-318
HOUSING SEAL - INSTALLATION,
ADAPTER...............21-128,21-364,21-85
HOUSING SEAL - INSTALLATION,
EXTENSION . 21-128,21-201,21-507,21-536,21-85
HOUSING SEAL - REMOVAL, ADAPTER . . 21-128,
21-364,21-85
HOUSING SEAL - REMOVAL,
EXTENSION . 21-128,21-201,21-507,21-536,21-85
HOUSING SEAL AND DUST BOOT -
INSTALLATION, EXTENSION.....21-476,21-571
HOUSING SEAL AND DUST BOOT -
REMOVAL, EXTENSION.........21-476,21-571
HOW TO USE WIRING DIAGRAMS -
DESCRIPTION.....................8W-01-1
H-SECTION REPLACEMENT - STANDARD
PROCEDURE, REAR FRAME............13-13
HUB / BEARING - INSTALLATION.........2-32
HUB / BEARING - REMOVAL.............2-31
HVAC HOUSING - ASSEMBLY...........24-35
HVAC HOUSING - DISASSEMBLY........24-35
HVAC HOUSING - INSTALLATION........24-36
HVAC HOUSING - REMOVAL............24-34
HYDRAULIC BOOSTER - DIAGNOSIS
AND TESTING........................5-30
HYDRAULIC LASH ADJUSTER -
DIAGNOSIS AND TESTING.........9-125,9-32
HYDRAULIC PRESSURE TEST -
DIAGNOSIS AND TESTING......21-141,21-316
HYDRAULIC SCHEMATICS, SCHEMATICS
AND DIAGRAMS..............21-176,21-337
HYDRAULIC TAPPETS - DIAGNOSIS AND
TESTING...........................9-210
HYDRAULIC TAPPETS - INSTALLATION . . . 9-211
HYDRAULIC TAPPETS - REMOVAL.......9-211
HYDROBOOST - INSTALLATION..........5-27
HYDROBOOST - INSTALLATION, ALL
EXCEPT.............................5-27
HYDROBOOST - REMOVAL..............5-26
HYDROBOOST - REMOVAL, ALL EXCEPT . . . 5-26
HYDRO-BOOST BRAKE BOOSTER -
INSTALLATION........................5-32
HYDRO-BOOST BRAKE BOOSTER -
REMOVAL
...........................5-31
HYDROFORM FENDER RAIL REPAIR -
STANDARD PROCEDURE
...............13-11
HYDROSTATIC LOCK - STANDARD
PROCEDURE
...................9-190,9-240
IDENTIFICATION - DESCRIPTION,
FASTENER
.........................Intro.-5
IDENTIFICATION AND INFORMATION -
DESCRIPTION, SECTION
.............8W-01-6
IDENTIFICATION NUMBER -
DESCRIPTION, VEHICLE
..............Intro.-1
IDLE AIR CONTROL MOTOR -
DESCRIPTION
.......................14-28
IDLE AIR CONTROL MOTOR -
INSTALLATION
.......................14-29
IDLE AIR CONTROL MOTOR -
OPERATION
.........................14-28
IDLE AIR CONTROL MOTOR - REMOVAL
. . 14-29
IDLER SHAFT - INSTALLATION
......9-179,9-81
IDLER SHAFT - REMOVAL
..........9-179,9-81
IGNITION - SPECIFICATIONS, TORQUE
.....8I-3
16 INDEXDR
Description Group-Page Description Group-Page Description Group-Page

IGNITION CIRCUIT SENSE -
DESCRIPTION.......................8E-10
IGNITION CIRCUIT SENSE - OPERATION . . 8E-11
IGNITION COIL - DESCRIPTION..........8I-11
IGNITION COIL - INSTALLATION.........8I-14
IGNITION COIL - OPERATION............8I-12
IGNITION COIL - REMOVAL.............8I-13
IGNITION COIL CAPACITOR -
DESCRIPTION........................8I-21
IGNITION COIL CAPACITOR -
INSTALLATION.......................8I-21
IGNITION COIL CAPACITOR - OPERATION . . 8I-21
IGNITION COIL CAPACITOR - REMOVAL . . . 8I-21
IGNITION COIL RESISTANCE, 3.7L V-6.....8I-5
IGNITION COIL RESISTANCE, 4.7L V-8.....8I-5
IGNITION COIL RESISTANCE, 5.7L V-8.....8I-5
IGNITION CONTROL - DESCRIPTION.......8I-1
IGNITION SWITCH - DESCRIPTION........19-9
IGNITION SWITCH - DESCRIPTION,
KEY-IN.............................19-11
IGNITION SWITCH - DIAGNOSIS AND
TESTING............................19-9
IGNITION SWITCH - INSTALLATION......19-11
IGNITION SWITCH - OPERATION.........19-9
IGNITION SWITCH - REMOVAL..........19-10
IGNITION SWITCH AND KEY LOCK
CYLINDER - DIAGNOSIS AND TESTING . . . 19-11
IGNITION TIMING, SPECIFICATIONS.......8I-5
IGNITION-OFF DRAW TEST - STANDARD
PROCEDURE........................8F-11
IMMOBILIZER MODULE - DESCRIPTION,
SENTRY KEY........................8E-13
IMMOBILIZER MODULE - INSTALLATION,
SENTRY KEY........................8E-15
IMMOBILIZER MODULE - OPERATION,
SENTRY KEY........................8E-13
IMMOBILIZER MODULE - REMOVAL,
SENTRY KEY........................8E-15
IMMOBILIZER MODULE (SKIM) -
DESCRIPTION, SENTRY KEY.............8Q-1
IMMOBILIZER MODULE (SKIM) -
OPERATION, SENTRY KEY..............8Q-2
IMMOBILIZER SYSTEM INDICATOR
LAMP - DESCRIPTION, SENTRY KEY......8Q-5
IMMOBILIZER SYSTEM INDICATOR
LAMP - OPERATION, SENTRY KEY........8Q-5
IMMOBILIZER SYSTEM INITIALIZATION,
STANDARD PROCEDURE - SENTRY
KEY................................8Q-3
IMMOBILIZER SYSTEM (SKIS) -
DESCRIPTION, SENTRY KEY.............8Q-1
IMMOBILIZER SYSTEM (SKIS) -
OPERATION, SENTRY KEY..............8Q-2
IMMOBILIZER SYSTEM TRANSPONDER
PROGRAMMING, STANDARD
PROCEDURE - SENTRY KEY.............8Q-4
IMPACT SENSOR - DESCRIPTION, SIDE . . 8O-59
IMPACT SENSOR - OPERATION, SIDE....8O-59
INCORRECT FLUID LEVEL - DIAGNOSIS
AND TESTING, EFFECTS OF......21-201,21-366
INDEPENDENT FRONT SUSPENSION -
DESCRIPTION, GEAR..................19-17
INDEPENDENT FRONT SUSPENSION -
INSTALLATION, GEAR.................19-18
INDEPENDENT FRONT SUSPENSION -
REMOVAL, GEAR.....................19-17
INDICATOR - DESCRIPTION, ABS........8J-17
INDICATOR - DESCRIPTION, AIRBAG.....8J-18
INDICATOR - DESCRIPTION, BRAKE/
PARK BRAKE........................8J-19
INDICATOR - DESCRIPTION, CARGO
LAMP
..............................8J-20
INDICATOR - DESCRIPTION, CHECK
GAUGES
............................8J-21
INDICATOR - DESCRIPTION, CRUISE
.....8J-22
INDICATOR - DESCRIPTION, DOOR AJAR
. . 8J-23
INDICATOR - DESCRIPTION, ETC
........8J-25
INDICATOR - DESCRIPTION, GEAR
SELECTOR
..........................8J-27
INDICATOR - DESCRIPTION, HIGH BEAM
. . 8J-28
INDICATOR - DESCRIPTION, LAMP OUT
. . . 8J-29
INDICATOR - DESCRIPTION, LOW FUEL
. . . 8J-30
INDICATOR - DESCRIPTION, SEATBELT
. . . 8J-34
INDICATOR - DESCRIPTION, SECURITY
. . . 8J-35
INDICATOR - DESCRIPTION, SERVICE
4WD
...............................8J-36
INDICATOR - DESCRIPTION, TOW/HAUL
. . . 8J-39INDICATOR - DESCRIPTION, TRANS
TEMP..............................8J-40
INDICATOR - DESCRIPTION, TURN
SIGNAL............................8J-40
INDICATOR - DESCRIPTION, UPSHIFT....8J-41
INDICATOR - DESCRIPTION, WAIT-TO-
START .............................8J-44
INDICATOR - DESCRIPTION, WASHER
FLUID..............................8J-44
INDICATOR - DESCRIPTION, WATER-IN-
FUEL..............................8J-45
INDICATOR - DIAGNOSIS AND TESTING,
BRAKE.............................8J-20
INDICATOR - OPERATION, ABS..........8J-17
INDICATOR - OPERATION, AIRBAG.......8J-18
INDICATOR - OPERATION, BRAKE/PARK
BRAKE.............................8J-19
INDICATOR - OPERATION, CARGO LAMP . . 8J-20
INDICATOR - OPERATION, CHECK
GAUGES............................8J-21
INDICATOR - OPERATION, CRUISE.......8J-22
INDICATOR - OPERATION, DOOR AJAR . . . 8J-23
INDICATOR - OPERATION, ETC..........8J-25
INDICATOR - OPERATION, GEAR
SELECTOR..........................8J-27
INDICATOR - OPERATION, HIGH BEAM....8J-28
INDICATOR - OPERATION, LAMP OUT....8J-29
INDICATOR - OPERATION, LOW FUEL.....8J-30
INDICATOR - OPERATION, SEATBELT.....8J-34
INDICATOR - OPERATION, SECURITY......8J-36
INDICATOR - OPERATION, SERVICE 4WD . . 8J-37
INDICATOR - OPERATION, TOW/HAUL....8J-39
INDICATOR - OPERATION, TRANS TEMP . . 8J-40
INDICATOR - OPERATION, TURN SIGNAL . . 8J-41
INDICATOR - OPERATION, UPSHIFT......8J-42
INDICATOR - OPERATION, WAIT-TO-
START .............................8J-44
INDICATOR - OPERATION, WASHER
FLUID..............................8J-44
INDICATOR - OPERATION, WATER-IN-
FUEL..............................8J-45
INDICATOR LAMP - DESCRIPTION,
SENTRY KEY IMMOBILIZER SYSTEM......8Q-5
INDICATOR LAMP - OPERATION,
SENTRY KEY IMMOBILIZER SYSTEM......8Q-5
INDICATOR LAMP (MIL) - DESCRIPTION,
MALFUNCTION.......................8J-31
INDICATOR LAMP (MIL) - OPERATION,
MALFUNCTION.......................8J-31
INDICATOR TEST - STANDARD
PROCEDURE, BUILT-IN................8F-10
INDICATORS - DIAGNOSIS AND
TESTING, TREAD WEAR................22-8
INERTIA HINGE COVER - INSTALLATION,
CENTER SEAT BACK..................23-77
INERTIA HINGE COVER - REMOVAL,
CENTER SEAT BACK..................23-77
INFLATION PRESSURES - DESCRIPTION,
TIRE................................22-7
INFO CENTER - DESCRIPTION,
ELECTRONIC VEHICLE.................8M-7
INFO CENTER - INSTALLATION,
ELECTRONIC VEHICLE.................8M-9
INFO CENTER - OPERATION,
ELECTRONIC VEHICLE.................8M-7
INFO CENTER - REMOVAL, ELECTRONIC
VEHICLE............................8M-9
INITIAL OPERATION - STANDARD
PROCEDURE, POWER STEERING
PUMP.............................19-40
INITIALIZATION, STANDARD PROCEDURE
- SENTRY KEY IMMOBILIZER SYSTEM....8Q-3
INJECTED RINGS - ASSEMBLY, WITH......3-13
INJECTED RINGS - DISASSEMBLY, WITH . . . 3-11
INJECTION PUMP - DESCRIPTION, FUEL . . 14-53
INJECTION PUMP - INSTALLATION, FUEL . 14-55
INJECTION PUMP - OPERATION, FUEL....14-53
INJECTION PUMP - REMOVAL, FUEL.....14-54
INJECTION PUMP TIMING - DIAGNOSIS
AND TESTING, FUEL..................14-53
INJECTOR - DESCRIPTION, FUEL . . . 14-26,14-74
INJECTOR - INSTALLATION, FUEL........14-77
INJECTOR - OPERATION, FUEL
.....14-26,14-74
INJECTOR - REMOVAL, FUEL
...........14-75
INJECTOR FIRING ORDER, DIESEL -
FUEL
..............................14-48
INJECTOR RAIL - DESCRIPTION, FUEL
....14-78
INJECTOR RAIL - INSTALLATION, FUEL
. . . 14-78INJECTOR RAIL - OPERATION, FUEL.....14-78
INJECTOR RAIL - REMOVAL, FUEL.......14-78
INLET AIR TEMPERATURE SENSOR/
PRESSURE SENSOR - DESCRIPTION.....14-79
INLET AIR TEMPERATURE SENSOR/
PRESSURE SENSOR - INSTALLATION.....14-79
INLET AIR TEMPERATURE SENSOR/
PRESSURE SENSOR - OPERATION.......14-79
INLET AIR TEMPERATURE SENSOR/
PRESSURE SENSOR - REMOVAL........14-79
INLET FILTER - INSTALLATION..........14-20
INLET FILTER - REMOVAL..............14-20
INLET HOSE - INSTALLATION, HEATER....24-64
INLET HOSE - REMOVAL, HEATER.......24-64
INNER BELT MOLDING - INSTALLATION,
FRONT DOOR.......................23-93
INNER BELT MOLDING - INSTALLATION,
REAR DOOR........................23-94
INNER BELT MOLDING - REMOVAL,
FRONT DOOR.......................23-93
INNER BELT MOLDING - REMOVAL,
REAR DOOR........................23-94
INPUT - OPERATION, ASD SENSE - PCM . . . 8I-5
INPUT CLUTCH ASSEMBLY - ASSEMBLY . 21-378
INPUT CLUTCH ASSEMBLY -
DESCRIPTION......................21-373
INPUT CLUTCH ASSEMBLY -
DISASSEMBLY......................21-374
INPUT CLUTCH ASSEMBLY - OPERATION . 21-373
INPUT SHAFT SEAL - INSTALLATION,
STEERING GEAR.......................19-29
INPUT SHAFT SEAL - REMOVAL,
STEERING GEAR.....................19-27
INPUT SPEED SENSOR - DESCRIPTION . . 21-382
INPUT SPEED SENSOR - INSTALLATION . 21-382
INPUT SPEED SENSOR - OPERATION....21-382
INPUT SPEED SENSOR - REMOVAL.....21-382
INSERTS - INSTALLATION, SPRING TIP....2-45
INSERTS - REMOVAL, SPRING TIP........2-44
INSIDE HANDLE ACTUATOR -
INSTALLATION..................23-22,23-32
INSIDE HANDLE ACTUATOR - REMOVAL . . 23-22,
23-31
INSTRUMENT CLUSTER - ASSEMBLY.....8J-15
INSTRUMENT CLUSTER - DESCRIPTION . . . 8J-2
INSTRUMENT CLUSTER - DIAGNOSIS
AND TESTING.......................8J-10
INSTRUMENT CLUSTER - DISASSEMBLY . . 8J-14
INSTRUMENT CLUSTER - INSTALLATION . . 8J-16
INSTRUMENT CLUSTER - OPERATION.....8J-6
INSTRUMENT CLUSTER - REMOVAL.....8J-14
INSTRUMENT PANEL ANTENNA CABLE -
INSTALLATION.......................8A-7
INSTRUMENT PANEL ANTENNA CABLE -
REMOVAL...........................8A-7
INSTRUMENT PANEL ASSEMBLY -
INSTALLATION.......................23-55
INSTRUMENT PANEL ASSEMBLY -
REMOVAL..........................23-52
INSTRUMENT PANEL CENTER BEZEL -
INSTALLATION.......................23-57
INSTRUMENT PANEL CENTER BEZEL -
REMOVAL..........................23-57
INSTRUMENT PANEL DEMISTER DUCTS
- INSTALLATION.....................24-37
INSTRUMENT PANEL DEMISTER DUCTS
- REMOVAL.........................24-36
INSTRUMENT PANEL DRIVER SIDE
BEZEL - INSTALLATION................23-58
INSTRUMENT PANEL DRIVER SIDE
BEZEL - REMOVAL...................23-58
INSTRUMENT PANEL DUCTS -
INSTALLATION.......................24-37
INSTRUMENT PANEL DUCTS - REMOVAL . 24-37
INSTRUMENT PANEL HEADLAMP
SWITCH BEZEL - INSTALLATION.........23-56
INSTRUMENT PANEL HEADLAMP
SWITCH BEZEL - REMOVAL............23-56
INSTRUMENT PANEL LOWER
SURROUND - INSTALLATION...........23-59
INSTRUMENT PANEL LOWER
SURROUND - REMOVAL
...............23-59
INSTRUMENT PANEL TOP COVER -
INSTALLATION
.......................23-59
INSTRUMENT PANEL TOP COVER -
REMOVAL
..........................23-58
INTAKE AIR HEATER - DESCRIPTION
.....14-80
INTAKE AIR HEATER - INSTALLATION
.....14-80
DRINDEX 17
Description Group-Page Description Group-Page Description Group-Page