warning light CHEVROLET DYNASTY 1993 Manual PDF

SYSTEMS TEST
WARNING: APPLY PARKING BRAKE AND/OR
BLOCK WHEELS BEFORE PERFORMING A TEST
WITH THE ENGINE OPERATING.
OBTAINING DIAGNOSTIC TROUBLE CODES
(1) Connect DRBII scan tool to the data link con-
nector located in the engine compartment near the
powertrain control module (PCM). (2) Start the engine if possible, cycle the transaxle
selector and the A/Cswitch if applicable. Shut off
the engine. (3) Turn the ignition switch on, access Read Fault
Screen. Record all the fault messages shown on the
DRBII scan tool. Observe the malfunction indicator
lamp (check engine lamp on the instrument panel).
The lamp should light for 3 seconds then go out (bulb
check).
STATE DISPLAY TEST MODE
The switch inputs used by the powertrain control
module (PCM) have only two recognized states,
HIGH and LOW. For this reason, the PCM cannot
recognize the difference between a selected switch po-
sition versus an open circuit, a short circuit, or a de-
fective switch. If the change is displayed, it can be
assumed that the entire switch circuit to the PCM is
functional. From the state display screen access ei-
ther State Display Inputs and Outputs or State Dis-
play Sensors.
STATE DISPLAY INPUTS AND OUTPUTS
Connect the DRBII scan tool to the vehicle and ac-
cess the State Display screen. Then access Inputs and
Outputs. The following is a list of the engine control
system functions accessible through the Inputs and
Outputs screen. Park/Neutral Switch (automatic transaxle only)
Speed Control Resume
Brake Switch
Speed Control On/Off
Speed Control Set
A/C Switch Sense
S/C (Speed Control) Vent Solenoid
S/C (Speed Control) Vacuum Solenoid
Torque Converter Clutch Solenoid (3 speed auto-
matic transaxle)
A/C Clutch Relay
EGR Solenoid
Auto Shutdown Relay
Radiator Fan Relay
Purge Solenoid
Malfunction Indicator (Check Engine) Lamp
STATE DISPLAY SENSORS
Connect the DRBII scan tool to the vehicle and ac-
cess the State Display screen. Then access Sensor
Display. The following is a list of the engine control
system functions accessible through the Sensor Dis-
play screen. Oxygen Sensor Signal
Coolant Temperature
Coolant Temp Sensor
Throttle Position
Minimum Throttle
Battery Voltage
MAP Sensor Reading
Idle Air Control Motor Position
Added Adaptive Fuel
Adaptive Fuel Factor
Barometric Pressure
Min Airflow Idl Spd
Engine Speed
Fault #1 Key-On Info
Module Spark Advance
Speed Control Target
Fault #2 Key-On Info
Fault #3 Key-On Info
Speed Control Status
Charging System Goal
Theft Alarm Status
Speed Control Switch Voltage
Map Sensor Voltage
Vehicle Speed
Oxygen Sensor State
MAP Gauge Reading
Throttle Opening (percentage)
Total Spark Advance
CIRCUIT ACTUATION TEST MODE
The circuit actuation test mode checks for proper
operation of output circuits or devices which the pow-
ertrain control module (PCM) cannot internally rec-
ognize. The PCM can attempt to activate these
outputs and allow an observer to verify proper oper-
ation. Most of the tests provide an audible or visual
indication of device operation (click of relay contacts,
spray fuel, etc.). With the exception of an intermit-
tent condition, if a device functions properly during
its test, it can be assumed that the device, its associ-
ated wiring, and its driver circuit are in working or-
der.
OBTAINING CIRCUIT ACTUATION TEST
Connect the DRBII scan tool to the vehicle and ac-
cess the Actuators screen. The following is a list of
the engine control system functions accessible
through Actuators screens. Stop All Tests
Ignition Coil #1
Fuel Injector #1
Idle Air Control Motor Open/Close
Ä FUEL SYSTEMS 14 - 45

the PCM to store diagnostic trouble codes for other
systems. For example, a fuel pressure problem will not
register a fault directly, but could cause a rich or lean
condition. This could cause the PCM to store an oxygen
sensor diagnostic trouble code. Fuel Pressure - The vacuum assisted fuel pressure
regulator controls fuel system pressure. The PCM
cannot detect a clogged fuel pump inlet filter, clogged
in-line fuel filter, stuck open regulator, 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 diagnostic 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. Engine Timing - The PCM cannot detect an incor-
rectly indexed timing belt, camshaft sprocket and
crankshaft sprocket. However, these could result in a
rich or lean condition causing the PCM to store an
oxygen sensor diagnostic trouble code. 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. Fuel Injector Mechanical Malfunctions - The
PCM cannot determine if a fuel injector is clogged, the
needle is sticking or if the wrong injector is installed.
However, these could result in a rich or lean condition
causing the PCM to store an oxygen sensor diagnostic
trouble code. Excessive Oil Consumption - Although the PCM
monitors exhaust stream oxygen content when the
system is in closed loop, it cannot determine excessive
oil consumption. Throttle Body Air Flow - The PCM cannot detect a
clogged or restricted air cleaner inlet or filter element. Evaporative System - The PCM cannot detect a
disconnected (open vacuum line) restricted, plugged or
loaded evaporative purge canister. 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. 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 connector pins.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 diagnostic 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.
DIAGNOSTIC TROUBLE CODES
A diagnostic trouble code indicates the powertrain
control module (PCM) has recognized an abnormal
condition in the system. Abnormal conditions are usu-
ally shorted or open circuits.
The technician can display diagnostic trouble codes in
two ways. The first way is to cycle the ignition switch and
count the number of times the malfunction indicator lamp
(check engine lamp on the instrument panel) flashes on
and off. The DRBII scan tool provides the second method
of displaying diagnostic trouble codes. Diagnostic trouble
codes indicate the results of a circuit failure, but do not
directly identify the failed component.
For a list of Diagnostic Trouble Codes, refer to
the charts at the end of this section.
OBTAINING DIAGNOSTIC TROUBLE CODES
USING DRBII SCAN TOOL
WARNING: APPLY PARKING BRAKE AND/OR BLOCK
WHEELS BEFORE PERFORMING ANY TEST ON AN
OPERATING ENGINE. (1) Connect DRBII scan tool to the data link (diag-
nostic) connector located in the engine compartment,
next to the PCM (Fig. 1). (2) If possible, start the engine and cycle the A/C
switch if applicable. Shut off the engine. (3)
Turn the ignition switch on, access Read Fault
Screen. Record all the diagnostic trouble codes shown on
the DRBII scan tool. [Observe the malfunction indicator
lamp (check engine lamp) on the instrument panel. The
lamp should light for 2 seconds then go out (bulb check)].
To erase diagnostic trouble codes, use the Erase
Trouble Code data screen on the DRBII scan tool.
USING THE MALFUNCTION INDICATOR LAMP (1) Cycle the ignition key On - Off - On - Off - On
within 5 seconds. (2) Count the number of times the malfunction indi-
cator lamp (check engine lamp on the instrument
panel) flashes on and off. The number of flashes
represents the trouble code. There is a slight pause be-
Ä FUEL SYSTEMS 14 - 71

(3) Ensure the injector holes are clean and all plugs
have been removed. (4) Lubricate the injector O-rings with a drop of
clean engine oil to ease installation. (5) Install the injector assembly into their holes.
Install mounting screws. Fuel rail assembly must be
drawn into the intake manifold evenly making sure
each injector enters its own hole. Once all injectors are
seated, tighten bolts to 23 N Im (200 in. lbs) torque.
(6) Connect vacuum hose to fuel pressure regulator.
(7) Close fuel tube clip around fuel tubes and install
fastener. (8) Lubricate the ends of the chassis fuel tubes with
a light coating of clean 30 weight engine oil. Connect
fuel supply and return hoses to chassis fuel tube
assembly. Pull back on the quick connect fittings to
ensure complete insertion. Refer to Quick Connect
Fittings in the Fuel Delivery section of this group. (9) Connect vacuum hose intake manifold nipple.
(10) Connect negative cable to battery.
CAUTION: When using the ASD Fuel System Test, the
Auto Shutdown (ASD) Relay remains energized for
either 7 minutes, until the test is stopped, or until the
ignition switch is turned to the Off position.
(11) With the DRBII scan tool, use the ASD Fuel
System Test to pressurize system and check for leaks.
FUEL INJECTOR
The fuel rail must be removed to service the injec-
tors. Refer to Fuel Injector Rail Assembly in this
section.
REMOVAL
WARNING: RELEASE FUEL SYSTEM PRESSURE BE-
FORE SERVICING FUEL SYSTEM COMPONENTS.
WHEN SERVICING FLEXIBLE FUEL VEHICLES,
WEAR METHANOL RESISTANT GLOVES AND EYE
PROTECTION AND AVOID BREATHING FUMES. DO NOT ALLOW METHANOL/GASOLINE MIXTURES TO
CONTACT SKIN. SERVICE VEHICLES IN WELL VEN-
TILATED AREAS AND AVOID IGNITION SOURCES.
NEVER SMOKE WHILE SERVICING THE VEHICLE.
(1) Disconnect electrical connector from injector
(Fig. 8).
(2) Position fuel rail assembly so that the fuel injec-
tors are easily accessible (Fig. 9). (3) Remove injector lock ring from fuel rail and
injector. Pull injector straight out of fuel rail receiver
cup. (4) Check injector O-ring for damage. Replace dam-
aged O-rings. If injector is reused, install a protective
cap on the injector tip to prevent damage. (5) Repeat steps for remaining injectors.
INSTALLATION
WARNING: FUEL INJECTORS AND INJECTOR
O-RINGS DESIGNED FOR GASOLINE ONLY VE-
HICLES CANNOT BE USED ON FLEXIBLE FUEL AA-
BODY VEHICLES. WHEN SERVICING THE FUEL SYS-
TEM OF A FLEXIBLE FUEL VEHICLE, ONLY USE
ORIGINAL EQUIPMENT OR EQUIVALENT REPLACE-
MENT COMPONENTS.
Fig. 7 Fuel Injector Ports
Fig. 8 Servicing Fuel Injectors
14 - 80 FUEL SYSTEMS Ä

HEATED OXYGEN SENSOR (O2SENSOR)
The oxygen sensor is installed in the exhaust man-
ifold (Fig. 16).
CAUTION: Do not pull on the oxygen sensor wires
when disconnecting the electrical connector.
WARNING: THE EXHAUST MANIFOLD MAY BE EX-
TREMELY HOT. USE CARE WHEN SERVICING THE
OXYGEN SENSOR. (1) Disconnect oxygen sensor electrical connector.
(2) Remove sensor using Tool C-4907 (Fig. 17).
Slightly tightening the sensor can ease removal.
When the sensor is removed, the exhaust manifold
threads must be cleaned with an 18 mm X 1.5 + 6E
tap. If using original sensor, coat the threads with
Loctite 771-64 anti-seize compound or equivalent.
New sensors are packaged with compound on the
threads and do not require additional compound.
Tighten the sensor to 27 N Im (20 ft. lbs.) torque.
Fig. 14 Solenoid Mounting
Fig. 15 PCM
Fig. 16 Heated Oxygen Sensor
Fig. 17 Oxygen Sensor Socket
14 - 112 FUEL SYSTEMS Ä

SYSTEM TESTS
WARNING: APPLY PARKING BRAKE AND/OR BLOCK
WHEELS BEFORE PERFORMING ANY TEST ON AN
OPERATING ENGINE.
OBTAINING DIAGNOSTIC TROUBLE CODES
(1) Connect DRBII scan tool to the data link connec-
tor located in the engine compartment near the pow-
ertrain control module (PCM). (2) Start the engine if possible, cycle the transaxle
selector and the A/Cswitch if applicable. Shut off the
engine. (3) Turn the ignition switch on, access Read Fault
Screen. Record all the fault messages shown on the
DRBII scan tool. Observe the malfunction indicator
lamp (Check Engine lamp on the instrument panel).
The lamp should light for 3 seconds then go out (bulb
check). Diagnostic trouble code erasure; access erase
diagnostic trouble code data
STATE DISPLAY TEST MODE
The switch inputs used by the powertrain control
module (PCM) have only two recognized states, HIGH
and LOW. For this reason, the PCM cannot recognize
the difference between a selected switch position ver-
sus an open circuit, a short circuit, or a defective
switch. If the change is displayed, it can be assumed
that the entire switch circuit to the PCM is functional.
From the state display screen access either State
Display Inputs and Outputs or State Display Sensors.
STATE DISPLAY INPUTS AND OUTPUTS
Connect the DRBII scan tool to the vehicle. Access
the State Display screen. Then access Inputs and
Outputs. The following is a list of the engine control
system functions accessible through the Inputs and
Outputs screen. Park/Neutral Switch
Speed Control Resume
Brake Switch
Speed Control On/Off
Speed Control Set
A/C Switch Sense
S/C Vent Solenoid
S/C Vacuum Solenoid
A/C Clutch Relay
EGR Solenoid
Auto Shutdown Relay
Radiator Fan Relay
Purge Solenoid
Torque Converter Clutch Solenoid
Malfunction Indicator Lamp (Check Engine Lamp)
STATE DISPLAY SENSORS
Connect the DRBII scan tool to the vehicle and ac-
cess the State Display screen. Then access Sensor
Display. The following is a list of the engine control
system functions accessible through the Sensor Dis-
play screen. Battery Temperature
Oxygen Sensor Signal
Engine Coolant Temperature
Engine Coolant Temp Sensor
Throttle Position
Minimum Throttle
Battery Voltage
MAP Sensor Reading
Idle Air Control Motor Position
Adaptive Fuel Factor
Barometric Pressure
Min Airflow Idle Speed
Engine Speed
Fault #1 Key-On Info
Module Spark Advance
Speed Control Target
Fault #2 Key-on Info
Fault #3 Key-on Info
Speed Control Status
Speed Control Switch Voltage
Charging System Goal
Theft Alarm Status
Map Sensor Voltage
Vehicle Speed
Oxygen Sensor State
MAP Gauge Reading
Throttle Opening (percentage)
Total Spark Advance
CIRCUIT ACTUATION TEST MODE
The circuit actuation test mode checks for proper
operation of output circuits or devices which the pow-
ertrain control module (PCM) cannot internally rec-
ognize. The PCM can attempt to activate these
outputs and allow an observer to verify proper oper-
ation. Most of the tests provide an audible or visual
indication of device operation (click of relay contacts,
spray fuel, etc.). Except for intermittent conditions, if
a device functions properly during testing, assume
the device, its associated wiring, and driver circuit
working correctly.
OBTAINING CIRCUIT ACTUATION TEST
Connect the DRBII scan tool to the vehicle and ac-
cess the Actuators screen. The following is a list of
the engine control system functions accessible
through Actuators screens. Stop All Tests
Ignition Coil #1
Fuel Injector #1
Fuel Injector #2
Fuel Injector #3
14 - 134 FUEL SYSTEMS Ä

HEATED OXYGEN SENSOR (O2SENSOR)
The oxygen sensor is installed in the exhaust man-
ifold (Fig. 21).
CAUTION: Do not pull on the oxygen sensor wires
when disconnecting the electrical connector. WARNING: THE EXHAUST MANIFOLD MAY BE EX-
TREMELY HOT. USE CARE WHEN SERVICING THE
OXYGEN SENSOR.
(1) Disconnect oxygen sensor electrical connector.
(2) Remove sensor using Tool C-4907 (Fig. 22).
Slightly tightening the sensor can ease removal.
When the sensor is removed, the exhaust manifold
threads must be cleaned with an 18 mm X 1.5 + 6E tap.
If using original sensor, coat the threads with Loctite
771-64 anti-seize compound or equivalent. New sen-
sors are packaged with compound on the threads and
do not require additional compound. The sensor must
be tightened to 27 N Im (20 ft. lbs.) torque.
Fig. 19 PCMÐAC Body
Fig. 20 PCMÐAG and AJ Bodies
Fig. 21 Heated Oxygen Sensor
Fig. 22 Oxygen Sensor Socket
14 - 144 FUEL SYSTEMS Ä

line. However, these could result in a rich or lean
condition causing an oxygen sensor fault to be stored in
the PCM. Secondary Ignition Circuit - The PCM cannot
detect an inoperative ignition coil, fouled or worn spark
plugs, ignition cross firing, or open spark plug cables. Engine Timing - The PCM cannot detect an incor-
rectly indexed timing chain, camshaft sprocket and
crankshaft sprocket. However, these could result in a
rich or lean condition causing an oxygen sensor fault to
be stored in the PCM. 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. Fuel Injector Malfunctions - The PCM cannot
determine if a fuel injector is clogged, the needle is
sticking or the wrong injector is installed. However,
these could result in a rich or lean condition causing an
oxygen sensor fault to be stored in the PCM. Excessive Oil Consumption - Although the PCM
monitors exhaust stream oxygen content when the
system is in closed loop, it cannot determine excessive
oil consumption. Throttle Body Air Flow - The PCM cannot detect a
clogged or restricted air cleaner inlet or filter element. Evaporative System - The PCM will not detect a
restricted, plugged or loaded evaporative purge canis-
ter. Vacuum Assist - Leaks or restrictions in the
vacuum circuits of vacuum assisted engine control
system devices are not monitored by the PCM. How-
ever, these could result in a MAP sensor fault being
stored in the PCM. PCM System Ground - The PCM cannot determine
a poor system ground. However, a diagnostic trouble
code may be generated as a result of this condition. PCM Connector Engagement - The PCM cannot
determine spread or damaged connector pins. How-
ever, a diagnostic trouble code may be generated as a
result of this condition.
HIGH AND LOW LIMITS
The powertrain control module (PCM) compares in-
put signal voltages from each input device with estab-
lished high and low limits for the device. If the input
voltage is not within limits and other diagnostic
trouble code criteria are met, a diagnostic trouble code
will be stored 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 a fault condition can be verified.
DIAGNOSTIC TROUBLE CODE DESCRIPTION
A diagnostic trouble code indicates that the power-
train control module (PCM) has recognized an abnor- mal condition in the system. Diagnostic trouble codes
can be obtained from the malfunction indicator lamp
(Check Engine lamp on the instrument panel) or from
the DRBII scan tool. Diagnostic trouble codes indicate
the results of a failure but do not identify the failed
component directly.
SYSTEM TESTS
WARNING: APPLY PARKING BRAKE AND/OR BLOCK
WHEELS BEFORE PERFORMING ANY TEST ON AN
OPERATING ENGINE.
OBTAINING DIAGNOSTIC TROUBLE CODES
(1) Connect the DRBII scan tool to the data link
connector located in the engine compartment near the
driver side strut tower (Fig. 1). (2) Start the engine if possible, cycle the transaxle
selector and the A/Cswitch if applicable. Shut off the
engine. (3) Turn the ignition switch on, access Read Fault
Screen. Record all the fault messages shown on the
DRBII scan tool. Observe the malfunction indicator
lamp (check engine lamp on the instrument panel). The
lamp should light for 2 seconds then go out (bulb
check). Diagnostic trouble code erasure; access erase
diagnostic trouble code data
STATE DISPLAY TEST MODE
The switch inputs used by the powertrain control
module (PCM) have only two recognized states, HIGH
and LOW. For this reason, the PCM cannot recognize
the difference between a selected switch position ver-
sus an open circuit, a short circuit, or a defective
switch. If the change is displayed, it can be assumed
that the entire switch circuit to the PCM is functional.
From the state display screen access either State
Display Inputs and Outputs or State Display Sensors.
STATE DISPLAY INPUTS AND OUTPUTS
Connect the DRBII scan tool to the vehicle and access
the State Display screen. Then access Inputs and
Outputs. The following is a list of the engine control
system functions accessible through the Inputs and
Outputs screen. Park/Neutral Switch
Speed Control Resume
Brake Switch
Speed Control On/Off
Speed Control Set
A/C Switch Sense
S/C Vent Solenoid
Ä FUEL SYSTEMS 14 - 163

is made with the camshaft gear. While holding the
sensor in this position, install and tighten the retain-
ing bolt 12 N Im (105 in. lbs.) torque.
(2) Connect camshaft position sensor electrical con-
nector to harness connector. Position connector away
from the accessory belt.
HEATED OXYGEN SENSOR (O2SENSOR) SERVICE
The oxygen sensor is installed in the exhaust mani-
fold (Fig. 27).
CAUTION: Do not pull on the oxygen sensor wire
when disconnecting the electrical connector.
WARNING: THE EXHAUST MANIFOLD MAY BE EX-
TREMELY HOT. USE CARE WHEN SERVICING THE
OXYGEN SENSOR.
(1) Disconnect oxygen sensor electrical connector
(Fig. 28). (2) Remove sensor using Tool C-4907 (Fig. 29).
Slightly tightening the sensor can ease removal. When the sensor is removed, the exhaust manifold
threads must be cleaned with an 18 mm X 1.5 + 6E tap.
If using original sensor, coat the threads with Loctite
771-64 anti-seize compound or equivalent. New sen-
sors are packaged with compound on the threads and
do not require additional compound. The sensor must
be tightened to 27 N Im (20 ft. lbs.) torque.
Fig. 27 Oxygen SensorÐ3.3L Engine
Fig. 28 Oxygen Sensor Connector
Fig. 29 Oxygen Sensor Socket
Ä FUEL SYSTEMS 14 - 177

WHEELS SERVICE PROCEDURES INDEX
page page
General Information ........................ 6
Tire and Wheel Balance .................... 6
Tire and Wheel Run Out .................... 7 Wheel Installation
......................... 6
Wheel Replacement ....................... 6
GENERAL INFORMATION
Original equipment wheels are designed for proper
operation at all loads up to the maximum vehicle ca-
pacity. All models use steel or cast aluminum drop center
wheels. The safety rim wheel (Fig. 1) has raised sec-
tions between the rim flanges and the rim well A.
Initial inflation of the tires forces the bead over
these raised sections. In case of tire failure the raised
sections help hold the tire in position on the wheel
until the vehicle can be brought to a safe stop. Cast aluminum wheels require special balance
weights and alignment equipment.
WHEEL INSTALLATION
The wheel studs and nuts are designed for specific
applications and must be replaced with equivalent
parts. Do not use replacement parts of lessor quality
or a substitute design. All aluminum and some steel
wheels have wheel stud nuts which feature an en-
larged nose. This enlarged nose is necessary to en-
sure proper retention of the aluminum wheels. Before installing the wheel, be sure to remove any
build up of corrosion on the wheel mounting surfaces
with scraping and wire brushing. Installing wheels
without good metal-to-metal contact could cause later
loosening of wheel nuts. This could adversely affect
the safety and handling of your vehicle. To install the wheel, position it properly on the
mounting surface using the hub pilot as a guide. All wheel nuts should be lightly tightened before progres-
sively tightening them in sequence (Fig. 2). Tighten
wheel nuts to 129 N Im (95 ft. lbs.). Never use oil or
grease on studs or nuts.
WHEEL REPLACEMENT
Wheels must be replaced if they:
² have excessive run out
² are bent or dented
² leak air through welds
² have damaged bolt holes
Wheel repairs employing hammering, heating, or
welding are not allowed. Original equipment replacement wheels are avail-
able through your dealer. When obtaining wheels from
any other source, the replacement wheels should be
equivalent in load carrying capacity. The wheel dimen-
sions (diameter, width, offset, and mounting configura-
tion) must match original equipment wheels. Failure to
use equivalent replacement wheels may adversely af-
fect the safety and handling of your vehicle. Replace-
ment with used wheels is not recommended as
their service history may have included severe
treatment or very high mileage and they could
fail without warning.
TIRE AND WHEEL BALANCE
Balancing need is indicated by vibration of seats,
floor pan, or steering wheel when driving over 90 km/h
(55 mph) on a smooth road.
Fig. 1 Safety Rim
Fig. 2 Tightening Wheel Nuts (5-Stud)
22 - 6 WHEELSÐTIRES Ä

BODY DIAGNOSTIC PROCEDURES INDEX
page page
Water Leaks ............................. 2 Wind Noise.............................. 3
WATER LEAKS
Water leaks can be caused by poor sealing, improper
body component alignment, body seam porosity, miss-
ing plugs, or blocked drain holes. Centrifugal and
gravitational force can cause water to drip from an
area somewhat distant from the actual leak point,
making leak detection difficult. All body sealing points
should be water tight in normal wet driving conditions.
Water flowing downward from the front of the vehicle
should not enter the passenger or luggage compart-
ment. Moving sealing surfaces will not always seal
water tight under all conditions. At times, side glass,
door, or convertible top seals will allow water to enter
the passenger compartment during high pressure
washing or hard driving rain (severe) conditions. Over
compensating on door, glass, or top adjustments to stop
a water leak that occurs under severe conditions, can
cause premature seal wear and excessive closing or
latching effort. After a repair procedure has been
performed, water test vehicle to verify leak has stopped
before returning vehicle to use.
VISUAL INSPECTION BEFORE WATER LEAK TESTS
Verify that floor and body plugs are in place, body
drains are clear and body components are aligned and
sealed. If component alignment or sealing is necessary,
refer to the appropriate section of this group for proper
procedures.
WATER LEAK TESTS
WARNING: DO NOT USE ELECTRIC SHOP LIGHTS
OR TOOLS IN WATER TEST AREA, PERSONAL IN-
JURY CAN RESULT.
When a determination has been made on the condi-
tions that a water leak occurs, simulate the conditions
as closely as possible.
² If a leak occurs when the car is parked in a steady
light rain, flood the leak area with a open ended garden
hose.
² If a leak occurs at highway speeds in a steady rain,
test the leak area with a stream or fan spray of water
from a garden hose with an adjustable nozzle. Direct
the spray in the direction comparable to actual condi-
tions. ²
If a leak seems to occur only when the vehicle is
parked on an incline, hoist the end or side of the vehicle
to simulate this condition before water testing. This
method can also be used when the leak occurs when the
vehicle accelerates, stops, or turns. If the leak occurs
on acceleration, hoist the front of the vehicle. If the
leak occurs when braking, hoist the back of the vehicle.
If the leak occurs on left turns, hoist the left side of the
vehicle. If the leak occurs on right turns, hoist the right
side of the vehicle. For hoisting recommendations refer
to Group 0, Lubrication and Maintenance, General
Information section.
WATER LEAK DETECTION
To detect a water leak point of entry, perform a water
test and watch for water tracks or droplets forming on
the inside if the vehicle. If necessary remove interior
trim covers or panels to gain visual access to the leak
area. If the hose can not be positioned without being
held, have someone help perform the water test. Some water leaks must be tested for a considerable
length of time to become apparent. When a leak ap-
pears, determine the highest point of the water track or
drop. The highest point usually will indicate the point
of entry. After leak point has been determined, repair
the leak and water test to verify that leak has stopped. Locating the entry point of water that is leaking into
a cavity between panels can be difficult. The trapped
water splashes or runs from the cavity it is dammed up
in, often at a distance from the entry point. Most water
leaks of this type become apparent after accelerating,
stopping, turning, or when on a incline.
MIRROR INSPECTION METHOD
When a leak point area is visually obstructed, use a
suitable mirror to gain visual access. A mirror can also
be used to deflect light to a limited access area to assist
in locating a leak point.
BRIGHT LIGHT LEAK TEST METHOD
Some water leaks in the luggage compartment can be
detected without water testing. Position the vehicle in
a brightly light area. From inside the darkened lug-
gage compartment inspect around seals and body
seams. If necessary, have a helper direct a drop light
over the suspected leak areas around the lug-
23 - 2 BODY Ä