2002 JEEP LIBERTY Ignition switch

(2) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 67.5 to 82.5 ohms. If OK, go to
Step 3. If not OK, replace the faulty relay.
(3) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, see Relay Circuit Test. If not OK,
replace the faulty relay.
RELAY CIRCUIT TEST
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information).
(1) The relay common feed terminal cavity (30) is
connected to fused battery feed. There should be bat-
tery voltage at the cavity for relay terminal 30 at all
times. If OK, go to Step 2. If not OK, repair the open
circuit to the fuse in the PDC as required.
(2) The relay normally closed terminal (87A) is not
used in this application. Go to Step 3.
(3) The relay normally open terminal cavity (87) is
connected to the compressor clutch coil. There should
be continuity between this cavity and the A/C com-
pressor clutch relay output circuit cavity of the com-
pressor clutch coil wire harness connector. If OK, go
to Step 4. If not OK, repair the open circuit as
required.
(4) The relay coil battery terminal (86) is con-
nected to the fused ignition switch output (run/start)circuit. There should be battery voltage at the cavity
for relay terminal 86 with the ignition switch in the
On position. If OK, go to Step 5. If not OK, repair the
open circuit to the fuse in the junction block as
required.
(5) The coil ground terminal cavity (85) is switched
to ground through the Powertrain Control Module
(PCM). There should be continuity between this cav-
ity and the A/C compressor clutch relay control cir-
cuit cavity of the PCM wire harness connector C
(gray) at all times. If not OK, repair the open circuit
as required.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the cover from the Power Distribution
Center (PDC).
(3) Refer to the label on the PDC for compressor
clutch relay identification and location.
(4) Unplug the compressor clutch relay from the
PDC.
INSTALLATION
(1) Install the compressor clutch relay by aligning
the relay terminals with the cavities in the PDC and
pushing the relay firmly into place.
(2) Install the PDC cover.
(3) Connect the battery negative cable.
(4) Test the relay operation.
A/C HEATER CONTROL
DESCRIPTION
Both the heater-only and A/C heater systems use a
combination of mechanical, electrical, and vacuum
controls. These controls provide the vehicle operator
with a number of setting options to help control the
climate and comfort within the vehicle. Refer to the
owner's manual in the vehicle glove box for more
information on the features, use, and suggested oper-
ation of these controls.
The heater-only or A/C heater control panel is
located to the right of the instrument cluster on the
instrument panel. The control panel contains a rota-
ry-type temperature control knob, a rotary-type mode
control switch knob, and a rotary-type blower motor
speed switch knob. The control also has a push but-
ton to activate the rear window defogger.
The heater-only or A/C heater control panel cannot
be repaired. If faulty or damaged, the entire unit
must be replaced. The illumination lamps are avail-
able for service replacement.
Fig. 10 COMPRESSOR CLUTCH RELAY
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
24 - 16 CONTROLSKJ
A/C COMPRESSOR CLUTCH RELAY (Continued)

(2) Install and tighten the a/c low pressure switch
on the accumulator fitting. The switch should be
hand-tightened onto the accumulator fitting.
(3) Plug the wire harness connector into the a/c
low pressure switch.
(4) Connect the battery negative cable.
BLEND DOOR ACTUATOR
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove A/C housing from vehicle(Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - REMOVAL).
(3) Remove the screws that secure the blend door
actuator to the top of the HVAC housing. (Fig. 14).
(4) Remove the blend door actuator.
INSTALLATION
(1) Install the blend door actuator in place.
(2) Install and tighten the screws that secure the
blend door actuator to the housing. Tighten the
mounting screws to 2.4 ( .34) N´m (21 ( 3) in. lbs.).
(3) Install the HVAC housing into the vehicle(Re-
fer to 24 - HEATING & AIR CONDITIONING/DIS-
TRIBUTION/HVAC HOUSING - INSTALLATION).
(4) Install the blend door actuator electrical con-
nector from the wiring harness through the glove
box.
(5) Connect the battery negative cable.
BLOWER MOTOR RELAY
DESCRIPTION
The blower motor relay is a International Stan-
dards Organization (ISO)-type relay. The relay is a
electromechanical device that switches battery cur-
rent from a fuse in the Power Distribution Center
(PDC) directly to the blower motor. The relay is ener-
gized when the relay coil is provided a voltage signal
by the ignition switch. (Refer to 24 - HEATING &
AIR CONDITIONING/CONTROLS/BLOWER
MOTOR RELAY - DIAGNOSIS AND TESTING)
OPERATION
The blower motor relay is installed in a wire har-
ness connector that is secured to the passenger side
outboard end of the HVAC housing in the passenger
compartment, next to the HVAC wire harness con-
nector.
The blower motor relay cannot be repaired and, if
faulty or damaged, it must be replaced.
Fig. 14 HEATER CORE REMOVAL/INSTALLATION
1 - HEATER CORE
2- MOUNTING SCREW HOLE
3- INLET AND OUTLET TUBES
4- VACUUM HARNESS
5- ACTUATOR SCREWS (3)
6- ELECTRIC BLEND DOOR ACTUATOR
7- MOUNTING SCREW HOLE
8- HEATER CORE RETAINER TABS (4)
24 - 20 CONTROLSKJ
A/C LOW PRESSURE SWITCH (Continued)

DIAGNOSIS AND TESTING - BLOWER MOTOR
RELAY
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.
RELAY TEST
The blower motor relay (Fig. 15) is located in the
PDC which is located under the hood.. Remove the
relay from the PDC to perform the following tests:
(1) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
no continuity between terminals 87 and 30. If OK, go
to Step 2. If not OK, replace the faulty relay.
(2) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 60.7 to 80.3 ohms. If OK, go to
Step 3. If not OK, replace the faulty relay.
(3) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, see the Relay Circuit Test. If not OK,
replace the faulty relay.
RELAY CIRCUIT TEST
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information).
(1) The relay common feed terminal cavity (30) is
connected to fused battery feed directly from a fuse
in the Power Distribution Center (PDC), and should
be hot at all times. Check for battery voltage at the
connector cavity for relay terminal 30. If OK, go to
Step 2. If not OK, repair the open circuit to the PDC
fuse as required.
(2) The relay normally closed terminal cavity (87A)
is not used for this application. Go to Step 3.
(3) The relay normally open terminal cavity (87) is
connected to the blower motor. When the relay is
energized, terminal 87 is connected to terminal 30
and provides full battery current to the blower motor
feed circuit. There should be continuity between the
connector cavity for terminal 87 and the blower
motor at all times. If OK, go to Step 4. If not OK,
repair the open circuit to the blower motor as
required.
(4) The coil battery terminal cavity (86) is con-
nected to the ignition switch. When the ignition
switch is placed in the On position, fused ignition
switch output is directed from a fuse in the junction
block to the relay electromagnetic coil to energize the
relay. There should be battery voltage at the connec-
tor cavity for relay terminal 86 with the ignition
switch in the On position. If OK, go to Step 5. If not
OK, repair the open circuit to the junction block fuse
as required.
(5) The coil ground terminal cavity (85) is con-
nected to ground. This terminal supplies the ground
for the relay electromagnet coil. There should be con-
tinuity between the connector cavity for relay termi-
nal 85 and a good ground at all times. If not OK,
repair the open circuit as required.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
Fig. 15 BLOWER MOTOR RELAY
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
KJCONTROLS 24 - 21
BLOWER MOTOR RELAY (Continued)

BLOWER MOTOR SWITCH
DESCRIPTION
The heater-only or A/C Heater blower motor is con-
trolled by a four position rotary-type blower motor
switch, mounted in the A/C Heater control panel. The
switch allows the selection of one of four blower
motor speeds, but can only be turned off by selecting
the Off position with the heater-only or A/C Heater
mode control switch knob.
OPERATION
The blower motor switch directs the blower motor
ground path through the mode control switch to the
blower motor resistor, or directly to ground, as
required to achieve the selected blower motor speed.
The blower motor switch cannot be repaired and, if
faulty or damaged, the entire heater-only or A/C
Heater control unit must be replaced.
DIAGNOSIS AND TESTING - BLOWER MOTOR
SWITCH
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information).
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. Check for continuity between the ground cir-
cuit cavity of the A/C Heater control wire harness
connector and a good ground. There should be conti-
nuity. 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 unplugged, place the A/C Heater mode control
switch knob 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 knob to each of the four speed
positions. There should be continuity at each driver
circuit terminal in only one blower motor switch
speed position. If OK, test and repair the blower
driver circuits between the A/C Heater control con-
nector and the blower motor resistor as required. If
not OK, replace the faulty A/C Heater control unit.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
The blower motor switch cannot be repaired and, if
faulty or damaged, the entire heater-only or A/C
Heater control unit must be replaced. (Refer to 24 -
HEATING & AIR CONDITIONING/CONTROLS/A/C
HEATER CONTROL - REMOVAL)
INSTALLATION
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) The blower motor switch cannot be repaired
and, if faulty or damaged the entire heater-only or
A/C heater control unit must be replaced(Refer to 24
- HEATING & AIR CONDITIONING/CONTROLS/
A/C HEATER CONTROL - INSTALLATION).
KJCONTROLS 24 - 23

DESCRIPTION - STATE DISPLAY TEST MODE
The switch inputs to the Powertrain Control Mod-
ule (PCM) have two recognized states; HIGH and
LOW. For this reason, the PCM cannot recognize the
difference between a selected switch position versus
an open circuit, a short circuit, or a defective switch.
If the State Display screen shows the change from
HIGH to LOW or LOW to HIGH, assume the entire
switch circuit to the PCM functions properly. Connect
the DRB scan tool to the data link connector and
access the state display screen. Then access either
State Display Inputs and Outputs or State Display
Sensors.
DESCRIPTION - CIRCUIT ACTUATION TEST
MODE
The Circuit Actuation Test Mode checks for proper
operation of output circuits or devices the Powertrain
Control Module (PCM) may not internally recognize.
The PCM attempts to activate these outputs and
allow an observer to verify proper operation. Most of
the tests provide an audible or visual indication of
device operation (click of relay contacts, fuel spray,
etc.). Except for intermittent conditions, if a device
functions properly during testing, assume the device,
its associated wiring, and driver circuit work cor-
rectly. Connect the DRB scan tool to the data link
connector and access the Actuators screen.
DESCRIPTION - DIAGNOSTIC TROUBLE CODES
A Diagnostic Trouble Code (DTC) indicates the
PCM has recognized an abnormal condition in the
system.Remember that DTC's are the results of a sys-
tem or circuit failure, but do not directly iden-
tify the failed component or components.
NOTE: For a list of DTC's, refer to the charts in this
section.
BULB CHECK
Each time the ignition key is turned to the ON
position, the malfunction indicator (check engine)
lamp on the instrument panel should illuminate for
approximately 2 seconds then go out. This is done for
a bulb check.
OBTAINING DTC'S USING DRB SCAN TOOL
(1) Connect the DRB scan tool to the data link
(diagnostic) connector. This connector is located in
the passenger compartment; at the lower edge of
instrument panel; near the steering column.
(2) Turn the ignition switch on and access the
ªRead Faultº screen.
(3) Record all the DTC's and ªfreeze frameº infor-
mation shown on the DRB scan tool.
(4) To erase DTC's, use the ªErase Trouble Codeº
data screen on the DRB scan tool.Do not erase any
DTC's until problems have been investigated
and repairs have been performed.
(M)Malfunction Indicator Lamp (MIL) illuminated during engine operation if this DTC was recorded
(depending if required by CARB and/or EPA). MIL is displayed as an engine icon on instrument panel.
(G)Generator lamp illuminated
Generic Scan
Tool P-CodeDRB Scan Tool Display Brief Description of DTC
P0030 (M) 1/1 O2 Sensor Heater Circuit
MalfunctionProblem detected in oxygen sensor heater relay circuit.
P0031 (M) 1/1 O2 Sensor Heater Circuit Low Problem detected in oxygen sensor heater relay circuit.
P0032 (M) 1/1 O2 Sensor Heater Circuit High Problem detected in oxygen sensor heater relay circuit.
P0036 (M) 1/2 O2 Sensor Heater Circuit
MalfunctionProblem detected in oxygen sensor heater relay circuit.
P0037 (M) 1/2 O2 Sensor Heater Circuit Low Problem detected in oxygen sensor heater relay circuit.
P0038 (M) 1/2 O2 Sensor Heater Circuit High Problem detected in oxygen sensor heater relay circuit.
P0043 (M) 1/3 O2 Sensor Heater Circuit Low Problem detected in oxygen sensor heater relay circuit.
P0044 (M) 1/3 O2 Sensor Heater Circuit High Problem detected in oxygen sensor heater relay circuit.
P0051 (M) 2/1 O2 Sensor Heater Circuit Low Problem detected in oxygen sensor heater relay circuit.
P0052 (M) 2/1 O2 Sensor Heater Circuit High Problem detected in oxygen sensor heater relay circuit.
25 - 2 EMISSIONS CONTROLKJ
EMISSIONS CONTROL (Continued)

DESCRIPTION - TASK MANAGER
The PCM is responsible for efficiently coordinating
the operation of all the emissions-related compo-
nents. The PCM is also responsible for determining if
the diagnostic systems are operating properly. The
software designed to carry out these responsibilities
is referred to as the 'Task Manager'.
DESCRIPTION - MONITORED SYSTEMS
There are new electronic circuit monitors that
check fuel, emission, engine and ignition perfor-
mance. These monitors use information from various
sensor circuits to indicate the overall operation of the
fuel, engine, ignition and emission systems and thus
the emissions performance of the vehicle.
The fuel, engine, ignition and emission systems
monitors do not indicate a specific component prob-
lem. They do indicate that there is an implied prob-
lem within one of the systems and that a specific
problem must be diagnosed.
If any of these monitors detect a problem affecting
vehicle emissions, the Malfunction Indicator Lamp
(MIL) will be illuminated. These monitors generate
Diagnostic Trouble Codes that can be displayed with
the MIL or a scan tool.
The following is a list of the system monitors:
²Misfire Monitor
²Fuel System Monitor
²Oxygen Sensor Monitor
²Oxygen Sensor Heater Monitor
²Catalyst Monitor
²Leak Detection Pump Monitor (if equipped)
All these system monitors require two consecutive
trips with the malfunction present to set a fault.
Refer to the appropriate Powertrain Diagnos-
tics Procedures manual for diagnostic proce-
dures.
The following is an operation and description of
each system monitor:
OXYGEN SENSOR (O2S) MONITOR
Effective control of exhaust emissions is achieved
by an oxygen feedback system. The most important
element of the feedback system is the O2S. The O2S
is located in the exhaust path. Once it reaches oper-
ating temperature 300É to 350ÉC (572É to 662ÉF), the
sensor generates a voltage that is inversely propor-
tional to the amount of oxygen in the exhaust. The
information obtained by the sensor is used to calcu-
late the fuel injector pulse width. This maintains a
14.7 to 1 Air Fuel (A/F) ratio. At this mixture ratio,
the catalyst works best to remove hydrocarbons (HC),
carbon monoxide (CO) and nitrogen oxide (NOx) from
the exhaust.The O2S is also the main sensing element for the
Catalyst and Fuel Monitors.
The O2S can fail in any or all of the following
manners:
²slow response rate
²reduced output voltage
²dynamic shift
²shorted or open circuits
Response rate is the time required for the sensor to
switch from lean to rich once it is exposed to a richer
than optimum A/F mixture or vice versa. As the sen-
sor starts malfunctioning, it could take longer to
detect the changes in the oxygen content of the
exhaust gas.
The output voltage of the O2S ranges from 0 to 1
volt. A good sensor can easily generate any output
voltage in this range as it is exposed to different con-
centrations of oxygen. To detect a shift in the A/F
mixture (lean or rich), the output voltage has to
change beyond a threshold value. A malfunctioning
sensor could have difficulty changing beyond the
threshold value.
OXYGEN SENSOR HEATER MONITOR
If there is an oxygen sensor (O2S) shorted to volt-
age DTC, as well as a O2S heater DTC, the O2S
fault MUST be repaired first. Before checking the
O2S fault, verify that the heater circuit is operating
correctly.
Effective control of exhaust emissions is achieved
by an oxygen feedback system. The most important
element of the feedback system is the O2S. The O2S
is located in the exhaust path. Once it reaches oper-
ating temperature 300É to 350ÉC (572 É to 662ÉF), the
sensor generates a voltage that is inversely propor-
tional to the amount of oxygen in the exhaust. The
information obtained by the sensor is used to calcu-
late the fuel injector pulse width. This maintains a
14.7 to 1 Air Fuel (A/F) ratio. At this mixture ratio,
the catalyst works best to remove hydrocarbons (HC),
carbon monoxide (CO) and nitrogen oxide (NOx) from
the exhaust.
The voltage readings taken from the O2S sensor
are very temperature sensitive. The readings are not
accurate below 300ÉC. Heating of the O2S sensor is
done to allow the engine controller to shift to closed
loop control as soon as possible. The heating element
used to heat the O2S sensor must be tested to ensure
that it is heating the sensor properly.
The O2S sensor circuit is monitored for a drop in
voltage. The sensor output is used to test the heater
by isolating the effect of the heater element on the
O2S sensor output voltage from the other effects.
KJEMISSIONS CONTROL 25 - 17
EMISSIONS CONTROL (Continued)

an associated limp in will take two trips to illumi-
nate the MIL.
Refer to the Diagnostic Trouble Codes Description
Charts in this section and the appropriate Power-
train Diagnostic Procedure Manual for diagnostic
procedures.
DESCRIPTION - NON-MONITORED CIRCUITS
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. For 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 injectoris 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 AIRFLOW
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.
DESCRIPTION - HIGH AND LOW LIMITS
The PCM compares input signal voltages from each
input device with established high and low limits for
the device. If the input voltage is not within limits
and other criteria are met, the PCM stores a diagnos-
tic trouble code in memory. Other diagnostic trouble
code criteria might include engine RPM limits or
input voltages from other sensors or switches that
must be present before verifying a diagnostic trouble
code condition.
DESCRIPTION - LOAD VALUE
ENGINE IDLE/NEUTRAL 2500 RPM/NEUTRAL
All Engines 2% to 8% of Maximum Load 9% to 17% of Maximum Load
25 - 20 EMISSIONS CONTROLKJ
EMISSIONS CONTROL (Continued)

BRAKE CALIPERS - OPERATION, DISC.....5-14
BRAKE CALIPERS - REMOVAL, DISC......5-14
BRAKE COMPONENTS, SPECIFICATIONS....5-6
BRAKE DRUM - DIAGNOSIS AND
TESTING............................5-27
BRAKE DRUM MACHINING - STANDARD
PROCEDURES........................5-27
BRAKE FLUID CONTAMINATION -
DIAGNOSIS AND TESTING..............5-26
BRAKE FLUID, SPECIFICATIONS..........5-27
BRAKE HOSE - INSTALLATION, FRONT.....5-10
BRAKE HOSE - INSTALLATION, REAR......5-10
BRAKE HOSE - REMOVAL, REAR..........5-9
BRAKE INDICATOR - DESCRIPTION,
BRAKE/PARK........................8J-13
BRAKE INDICATOR - DIAGNOSIS AND
TESTING...........................8J-14
BRAKE INDICATOR - OPERATION,
BRAKE/PARK........................8J-13
BRAKE LAMP SWITCH - DESCRIPTION . . . 8L-16
BRAKE LAMP SWITCH - DIAGNOSIS
AND TESTING.......................8L-17
BRAKE LAMP SWITCH - INSTALLATION . . . 8L-18
BRAKE LAMP SWITCH - OPERATION.....8L-16
BRAKE LAMP SWITCH - REMOVAL......8L-17
BRAKE LINE AND HOSES - DIAGNOSIS
AND TESTING.........................5-8
BRAKE LINES - DESCRIPTION............5-8
BRAKE PADS - INSTALLATION, FRONT.....5-11
BRAKE PADS - REMOVAL, FRONT........5-11
BRAKE ROTOR - DIAGNOSIS AND
TESTING, DISC.......................5-18
BRAKE ROTOR - STANDARD
PROCEDURE, DISC....................5-19
BRAKE SHOES - INSTALLATION, DRUM....5-11
BRAKE SHOES - REMOVAL, DRUM.......5-11
BRAKE SYSTEM - DIAGNOSIS AND
TESTING, BASE........................5-3
BRAKE TRANSMISSION SHIFT
INTERLOCK SYSTEM - DESCRIPTION....21-124
BRAKE TRANSMISSION SHIFT
INTERLOCK SYSTEM - DIAGNOSIS
AND TESTING......................21-125
BRAKE TRANSMISSION SHIFT
INTERLOCK SYSTEM - OPERATION.....21-125
BRAKE/PARK BRAKE INDICATOR -
DESCRIPTION.......................8J-13
BRAKE/PARK BRAKE INDICATOR -
OPERATION.........................8J-13
BRAKES - ABS - DESCRIPTION...........5-32
BRAKES - ABS - OPERATION............5-32
BRAKES - ABS - SPECIFICATIONS........5-33
BRAKES - BASE - DESCRIPTION...........5-2
BRAKES - BASE - WARNING..............5-2
BRAKES, SPECIAL TOOLS - BASE.........5-7
BRAKING SYSTEM - DIAGNOSIS AND
TESTING, ANTILOCK...................5-33
BREAK-IN - STANDARD PROCEDURE,
A/C COMPRESSOR CLUTCH............24-12
BUCKLE - INSTALLATION, FRONT SEAT
BELT ..............................8O-26
BUCKLE - INSTALLATION, REAR SEAT
BELT ..............................8O-35
BUCKLE - REMOVAL, FRONT SEAT BELT . . 8O-25
BUCKLE - REMOVAL, REAR SEAT BELT . . . 8O-34
BUILT-IN INDICATOR TEST - STANDARD
PROCEDURE........................8F-10
BULB - INSTALLATION, ASH RECEIVER
LAMP..............................8L-71
BULB - INSTALLATION, CARGO LAMP....8L-73
BULB - INSTALLATION, CENTER HIGH
MOUNTED STOP LAMP................8L-19
BULB - INSTALLATION, COMPASS
MINI-TRIP ILLUMINATION..............8L-75
BULB - INSTALLATION, COURTESY
LAMP..............................8L-76
BULB - INSTALLATION, FRONT FOG
LAMP..............................8L-22
BULB - INSTALLATION, FRONT LAMP....8L-27
BULB - INSTALLATION, FRONT POSITION
LAMP..............................8L-28
BULB - INSTALLATION, HEADLAMP
......8L-32
BULB - INSTALLATION, HEATER-A/C
CONTROL ILLUMINATION
..............8L-78
BULB - INSTALLATION, LICENSE PLATE
LAMP
..............................8L-45
BULB - INSTALLATION, READING LAMP
. . . 8L-79
BULB - INSTALLATION, REAR LAMP
.....8L-59BULB - INSTALLATION, REPEATER LAMP . . 8L-60
BULB - INSTALLATION, TRANSMISSION
RANGE INDICATOR ILLUMINATION.......8L-83
BULB - INSTALLATION, VANITY LAMP....8L-84
BULB - REMOVAL, ASH RECEIVER LAMP . . 8L-71
BULB - REMOVAL, CARGO LAMP........8L-72
BULB - REMOVAL, CENTER HIGH
MOUNTED STOP LAMP................8L-18
BULB - REMOVAL, COMPASS MINI-TRIP
ILLUMINATION......................8L-74
BULB - REMOVAL, COURTESY LAMP.....8L-75
BULB - REMOVAL, FRONT FOG LAMP....8L-21
BULB - REMOVAL, FRONT LAMP........8L-26
BULB - REMOVAL, FRONT POSITION
LAMP..............................8L-28
BULB - REMOVAL, HEADLAMP..........8L-31
BULB - REMOVAL, HEATER-A/C
CONTROL ILLUMINATION..............8L-78
BULB - REMOVAL, LICENSE PLATE
LAMP..............................8L-44
BULB - REMOVAL, READING LAMP......8L-79
BULB - REMOVAL, REAR LAMP.........8L-58
BULB - REMOVAL, REPEATER LAMP.....8L-60
BULB - REMOVAL, TRANSMISSION
RANGE INDICATOR ILLUMINATION.......8L-82
BULB - REMOVAL, VANITY LAMP........8L-83
BUMPER - INSTALLATION, JOUNCE.......2-19
BUMPER - REMOVAL, JOUNCE...........2-19
BURNT FLUID - DIAGNOSIS AND
TESTING, CAUSES OF................21-125
BUSHING - NV3550 - INSTALLATION,
EXTENSION HOUSING.................21-74
BUSHING - NV3550 - REMOVAL,
EXTENSION HOUSING.................21-73
BUSHINGS - INSTALLATION, STABILIZER
BAR.................................2-9
BUSHINGS - REMOVAL, STABILIZER BAR . . . 2-9
BUSHINGS, AND BALL JOINT -
DESCRIPTION, UPPER SUSPENSION
ARM ...............................2-20
BUSHINGS, AND BALL JOINT -
OPERATION, UPPER SUSPENSION
ARM ...............................2-20
CABLE - ADJUSTMENTS, GEARSHIFT....21-130
CABLE - ADJUSTMENTS, PARK-
INTERLOCK........................21-154
CABLE - DESCRIPTION.................8P-3
CABLE - DESCRIPTION, ANTENNA BODY . . . 8A-4
CABLE - DIAGNOSIS AND TESTING,
ANTENNA BODY......................8A-5
CABLE - DIAGNOSIS AND TESTING,
GEARSHIFT........................21-128
CABLE - INSTALLATION, ANTENNA BODY . . 8A-6
CABLE - INSTALLATION, GEARSHIFT....21-129
CABLE - INSTALLATION, INSTRUMENT
PANEL ANTENNA......................8A-8
CABLE - INSTALLATION, LATCH RELEASE . 23-120
CABLE - INSTALLATION, PARK -
INTERLOCK........................21-153
CABLE - INSTALLATION, THROTTLE
CONTROL..........................14-46
CABLE - OPERATION...................8P-3
CABLE - OPERATION, ANTENNA BODY.....8A-5
CABLE - REMOVAL, ANTENNA BODY......8A-6
CABLE - REMOVAL, GEARSHIFT........21-128
CABLE - REMOVAL, INSTRUMENT PANEL
ANTENNA...........................8A-7
CABLE - REMOVAL, LATCH RELEASE....23-120
CABLE - REMOVAL, PARK - INTERLOCK . 21-153
CABLE - REMOVAL, THROTTLE
CONTROL..........................14-45
CABLE RESISTANCE, 2.4L - SPARK PLUG . . . 8I-3
CABLES - DESCRIPTION, BATTERY.......8F-18
CABLES - DIAGNOSIS AND TESTING,
BATTERY...........................8F-19
CABLES - INSTALLATION...............5-30
CABLES - OPERATION, BATTERY........8F-18
CABLES - REMOVAL...................5-30
CALIBRATION - STANDARD PROCEDURE,
COMPASS...........................8M-2
CALIPER ADAPTER - INSTALLATION,
DISC BRAKE.........................5-18
CALIPER ADAPTER - REMOVAL, DISC
BRAKE
..............................5-18
CALIPERS - ASSEMBLY, DISC BRAKE
......5-16
CALIPERS - CLEANING, DISC BRAKE
......5-16
CALIPERS - DESCRIPTION, DISC BRAKE
. . . 5-13
CALIPERS - DISASSEMBLY, DISC BRAKE
. . . 5-14CALIPERS - INSPECTION, DISC BRAKE....5-16
CALIPERS - INSTALLATION, DISC BRAKE . . . 5-17
CALIPERS - OPERATION, DISC BRAKE.....5-14
CALIPERS - REMOVAL, DISC BRAKE......5-14
CAMBER AND CASTER ADJUSTMENT -
STANDARD PROCEDURE.................2-5
CAMBER, CASTER AND TOE
ADJUSTMENT - STANDARD
PROCEDURE..........................2-5
CAMSHAFT(S) - DESCRIPTION.......9-23,9-33
CAMSHAFT(S) - INSTALLATION......9-25,9-33
CAMSHAFT(S) - REMOVAL..........9-24,9-33
CANISTER - DESCRIPTION, VAPOR......25-33
CANISTER - INSTALLATION, VAPOR......25-33
CANISTER - OPERATION, VAPOR........25-33
CANISTER - REMOVAL, VAPOR..........25-33
CAP - CLEANING, RADIATOR PRESSURE . . . 7-25
CAP - DESCRIPTION, FUEL FILLER.......25-27
CAP - DESCRIPTION, RADIATOR
PRESSURE..........................7-25
CAP - DIAGNOSIS AND TESTING,
RADIATOR PRESSURE.................7-25
CAP - INSPECTION, RADIATOR
PRESSURE..........................7-25
CAP - INSTALLATION, INSTRUMENT
PANEL END........................23-153
CAP - OPERATION, FUEL FILLER........25-27
CAP - OPERATION, RADIATOR
PRESSURE..........................7-25
CAP - REMOVAL, INSTRUMENT PANEL
END ..............................23-153
CAPACITIES - SPECIFICATIONS, FLUID......0-4
CAPACITOR - DESCRIPTION, IGNITION
COIL...............................8I-16
CAPACITOR - INSTALLATION, IGNITION
COIL...............................8I-16
CAPACITOR - OPERATION, IGNITION
COIL...............................8I-16
CAPACITOR - REMOVAL, IGNITION COIL . . . 8I-16
CAPACITY - SPECIFICATIONS, CHARGE . . . 24-42
CAPACITY TEST - DIAGNOSIS AND
TESTING, FUEL PUMP.................14-15
CARDAN UNIVERSAL JOINTS -
ASSEMBLY, SINGLE.....................3-9
CARDAN UNIVERSAL JOINTS -
DISASSEMBLY, SINGLE..................3-8
CARGO LAMP BULB - INSTALLATION.....8L-73
CARGO LAMP BULB - REMOVAL........8L-72
CARGO LAMP SWITCH - INSTALLATION . . 8L-74
CARGO LAMP SWITCH - REMOVAL......8L-73
CARGO LAMP UNIT - INSTALLATION.....8L-74
CARGO LAMP UNIT - REMOVAL.........8L-74
CARPETS AND FLOOR MATS -
INSTALLATION......................23-158
CARPETS AND FLOOR MATS - REMOVAL . 23-158
CASE - NV231 - ASSEMBLY, TRANSFER . . 21-194
CASE - NV231 - CLEANING, TRANSFER . . 21-190
CASE - NV231 - DESCRIPTION,
TRANSFER............................0-3
CASE - NV231 - DESCRIPTION,
TRANSFER.........................21-178
CASE - NV231 - DIAGNOSIS AND
TESTING, TRANSFER.................21-180
CASE - NV231 - DISASSEMBLY,
TRANSFER.........................21-182
CASE - NV231 - INSPECTION, TRANSFER . 21-190
CASE - NV231 - INSTALLATION,
TRANSFER.........................21-205
CASE - NV231 - OPERATION, TRANSFER
. 21-179
CASE - NV231 - REMOVAL, TRANSFER
. . 21-181
CASE - NV242 - ASSEMBLY, TRANSFER
. . 21-230
CASE - NV242 - CLEANING, TRANSFER
. . 21-227
CASE - NV242 - DESCRIPTION,
TRANSFER
............................0-3
CASE - NV242 - DESCRIPTION,
TRANSFER
.........................21-215
CASE - NV242 - DIAGNOSIS AND
TESTING, TRANSFER
.................21-216
CASE - NV242 - DISASSEMBLY,
TRANSFER
.........................21-218
CASE - NV242 - INSPECTION, TRANSFER
. 21-228
CASE - NV242 - INSTALLATION,
TRANSFER
.........................21-243
CASE - NV242 - OPERATION, TRANSFER
. 21-215
CASE - NV242 - REMOVAL, TRANSFER
. . 21-217
CASE BEARINGS - INSTALLATION,
DIFFERENTIAL
...............3-110,3-44,3-79
4 INDEXKJ
Description Group-Page Description Group-Page Description Group-Page