1993 CHEVROLET PLYMOUTH ACCLAIM radiator

(3) Inspect the spark plug condition. Refer to Spark
Plug Condition in this section.
SPARK PLUG GAP ADJUSTMENT
Check the spark plug gap with a gap gauge. If the
gap is not correct, adjust it by bending the ground
electrode (Fig. 6).
SPARK PLUG INSTALLATION
(1) Start the spark plug into the cylinder head by
hand to avoid cross threading. (2) Tighten spark plugs to 28 N Im (20 ft. lbs.)
torque. (3) Install spark plug cables over spark plugs.
IDLE RPM TESTÐ2.5L AND 3.0L ENGINES
WARNING: APPLY PARKING BRAKE AND/OR BLOCK
WHEELS BEFORE PERFORMING IDLE CHECK OR
ADJUSTMENT, OR ANY TESTS WITH A RUNNING
ENGINE.
Engine idle set rpmshould be recorded when the
vehicle is first brought into shop for testing. This
will assist in diagnosing complaints of engine stalling,
creeping and hard shifting on vehicles equipped with
automatic transaxles. Proceed to the Throttle Body Minimum Airflow pro-
cedures in Group 14.
IGNITION TIMING PROCEDUREÐ2.2L TBI, 2.5L
TBI, 2.5L MPI, AND 3.0L ENGINES
WARNING: APPLY PARKING BRAKE AND/OR BLOCK
WHEELS BEFORE PERFORMING SETTING IGNITION
TIMING OR PERFORMING ANY TEST ON AN OPER-
ATING ENGINE.
Proper ignition timing is required to obtain optimum
engine performance. The distributor must be correctly
indexed to provide correct initial ignition timing. (1) Set the gearshift selector in park or neutral and
apply the parking brake. All lights and accessories
must be off. (2) If using a magnetic timing light, insert the
pickup probe into the open receptacle next to the
timing scale window. If a magnetic timing unit is not
available, use a conventional timing light connected to
the number one cylinder spark plug cable. Do not puncture cables, boots or nipples with
test probes. Always use proper adapters. Punc-
turing the spark plug cables with a probe will
damage the cables. The probe can separate the
conductor and cause high resistance. In addition
breaking the rubber insulation may permit sec-
ondary current to arc to ground. (3) Turn selector switch to the appropriate cylinder
position. (4) Start engine and run until operating tempera-
ture is obtained. (5) With the engine at normal operating tempera-
ture, connect the DRBII scan tool to the data link
connector (diagnostic connector). Access the State Dis-
play screen. Refer to the appropriate Powertrain Diag-
nostics Procedures Manual. If not using the DRBII
scan tool, disconnect the coolant temperature
sensor electrical connector. The electric radiator
fan will operate and the malfunction indicator lamp
(instrument panel Check Engine light) will turn on
after disconnecting the coolant sensor or starting the
DRBII scan tool procedure. (6) Aim Timing Light at timing scale (Fig. 7 or Fig.
8) or read magnetic timing unit. If flash occurs when
timing mark is before specified degree mark, timing is
advanced. To adjust, turn distributor housing in direc-
tion of rotor rotation. If flash occurs when timing mark is after specified
degree mark, timing is retarded. To adjust, turn dis-
tributor housing against direction of rotor rotation.
Refer to Vehicle Emission Control Information label for
correct timing specification. If timing is within 62É of
value specified on the label, proceed to step (8). If
outside specified tolerance, proceed to next step. (7) Loosen distributor hold-down arm screw
enough to rotate the distributor housing (Fig. 9 or
Fig. 6 Setting Spark Plug GapÐTypical
8D - 16 IGNITION SYSTEMS Ä

EXTERIOR LAMPSÐAA BODY INDEX
page page
Center High-Mounted Stop Lamp (CHMSL) Bulb . . 9
Fog Lamp ............................... 9
Fog Lamp Bulb ........................... 9
Front Side Marker Lamp or Bulb .............. 7
Headlamp Bulb ........................... 7 Headlamp Lens
........................... 7
License Plate Lamp or BulbÐAA/P Body ....... 8
License Plate LampsÐAA/C Body ............. 8
Park and Turn Signal Lamp or Bulb ........... 7
Tail, Stop and Turn Signal and Back-Up Lamp . . . 8
HEADLAMP BULB
REMOVAL (FIG. 1)
(1) Raise hood to the open position.
(2) Disconnect wire connector from lamp socket be-
hind the headlamp in the engine compartment. (3) Rotate bulb retaining ring counterclockwise
one quarter turn and remove the ring from the lamp. (4) Pull bulb from the lens assembly. When install-
ing bulb, align notches on bulb base to grooves in
lamp opening.
CAUTION: Do not touch the bulb with fingers or any
possibly oily surface, reduced bulb life will result.
INSTALLATION
Reverse the preceding operation.
HEADLAMP LENS
REMOVAL
(1) Raise hood to the open position.
(2) Disconnect wire connector from back of head-
lamp bulb. (3) Remove screws holding side marker lamp to
front fender. (4) Separate side marker lamp from fender and re-
move bulb socket from lamp. (5) Remove screws holding headlamp to radiator
closure panel. (6) Separate headlamp from radiator closure panel.
INSTALLATION
Reverse the preceding operation.
PARK AND TURN SIGNAL LAMP OR BULB
REMOVAL (FIG. 2)
(1) Remove screws holding park and turn signal
lamp to bumper fascia. (2) Separate lamp from bumper fascia.
(3) Remove socket from lamp.
(4) Pull bulb from socket.
INSTALLATION
Reverse the preceding operation.
FRONT SIDE MARKER LAMP OR BULB
REMOVAL (FIG. 3)
(1) Remove lamp assembly attaching screws and
separate the lamp from the front fender opening. (2) Rotate the side marker lamp socket counter-
clockwise one quarter turn and pull the socket and
bulb from the lamp. (3) Remove the bulb from the socket.
Fig. 1 Aero Headlamp
Fig. 2 Park and Turn Signal Lamp
Ä LAMPS 8L - 7

AERO HEADLAMP HOUSING
REMOVAL (FIG. 4 AND 5)
To remove the aero headlamp housing, perform
steps (1) and (2) of bulb removal operation and pro-
ceed with the following procedures. (1) The battery may have to be removed to replace
the left front headlamp bulb or lens. (2) From inside the engine compartment, unsnap
the headlamp adjuster cables from the headlamp ad-
juster screws. (3) Remove the four headlamp lens attaching nuts
from behind the grille opening panel, and remove the
lamp housing from the vehicle.
INSTALLATION
Reverse the preceding operation.
PARK/TURN SIGNAL LAMP OR BULBÐAC/D-BODY
REMOVAL (FIG. 6)
(1) Remove nut holding park turn signal lamp to
the GOP through an access hole in the radiator clo-
sure panel from behind the lamp. (2) Separate the park and turn signal lamp from
the GOP. (3) Remove the socket from the lamp
(4) Pull the bulb from the socket if bulb replace-
ment is required.
INSTALLATION
Reverse the preceding operation.
PARK/TURN SIGNAL LAMP OR BULBÐAC/C-BODY
REMOVAL (FIG. 7)
(1) Remove the two park and turn signal lamp at-
taching screws. (2) Separate the lamp from the front bumper fascia
and remove the bulb and socket assembly.
Fig. 3 Sealed Beam ReplacementÐTypical
Fig. 4 Aero HeadlampÐAC/D-Body
Fig. 5 Headlamp Adjuster CablesÐAC/D-Body
Fig. 6 Park, Turn Signal, Cornering and Side Marker LampsÐAC/D-Body
Ä LAMPS 8L - 11

EXTERIOR LAMPSÐAP BODY INDEX
page page
Center High Mounted Stop Lamp (CHMSL)Ð AP/24-44-Body ......................... 21
Center High Mounted Stop Lamp BulbÐ AP/24-44-Body ......................... 21
Fog Lamp Bulb .......................... 21
Fog Lamps ............................. 21
Front Side Marker Lamp or Bulb ............. 20
Headlamp Bulb .......................... 19 Headlamp Diagnosis
...................... 19
Headlamp Housing ....................... 19
License Plate Lamp or Bulb ................ 20
Park and Turn Signal Lamp or Bulb .......... 20
Tail, Stop, Turn Signal, Back-Up and Side Marker Lamp ................................ 20
Tail, Stop, Turn Signal, Back-Up and Side Marker Lamp Bulbs ........................... 20
HEADLAMP DIAGNOSIS
For headlamp diagnosis, refer to the headlamp di-
agnosis chart at the beginning of this group. Refer to
Wiring Diagrams manual for circuit and component
locations.
HEADLAMP BULB
REMOVAL (FIG. 1)
(1) Left front bulb removal: Remove the windshield
washer reservoir upper mounting screw and position
reservoir rearward. (2) Disconnect wire connector from back of head-
lamp behind radiator closure panel.
CAUTION: Do not touch the bulb glass with fingers
or other oily surface, reduced bulb life will result.
(3) Rotate the bulb retaining ring counterclockwise
one quarter turn and remove the ring, bulb holder
and bulb from the lens assembly. The bulb holder
has alignment notches.
INSTALLATION
Reverse the preceding operation.
HEADLAMP HOUSING
RIGHT HEADLAMP REMOVAL (FIG. 1)
To remove the aero headlamp housing, perform
steps 1, 2 and 3 of bulb removal operation and pro-
ceed with the following steps. (1) From in the engine compartment, remove the
three headlamp assembly to body attaching nuts and
separate the lamp from the body. (2) Pull headlamp/lens assembly forward.
(3) Pull the lower section of the headlamp adjuster
cable from the lamp adjuster screw.
(4) Remove headlamp/lens assembly.
(5) Remove the four lamp/lens to headlamp bucket
screws. (6) Remove headlamp/lens.
INSTALLATION
Reverse the preceding operation.
LEFT HEADLAMP REMOVAL (FIG. 1)
(1) Disconnect battery cables, negative first, and
remove battery. (2) Remove the windshield washer reservoir upper
mounting screw and position reservoir rearward. (3) Remove the air cleaner intake tube.
(4) Remove screws holding Engine Controller to in-
ner fender flange. (5) Move Engine Controller rearward, leave wires
connected. (6) Remove air duct from front of Engine Control-
ler. (7) Disconnect wire connector from back of head-
lamp. (8) From in the engine compartment, remove nuts
holding headlamp housing to radiator closure panel. (9) Separate headlamp housing from radiator clo-
sure panel. (10) Pull headlamp housing forward.
(11) Pull the lower section of the headlamp ad-
juster cable from the lamp adjuster screw. (12) Separate headlamp from vehicle.
INSTALLATION
Reverse the preceding operation.
Fig. 1 Aero Headlamp
Ä LAMPS 8L - 19

CONCEALED HEADLAMPS INDEX
page page
Concealed Headlamp MotorÐAC-Body ........ 29
Diagnostic Procedures ..................... 27
General Information ....................... 27 Headlamp DoorÐAC-Body
................. 29
Headlamp DoorÐAY Body ................. 29
Headlamp Drive MotorÐAY Body ............ 30
GENERAL INFORMATION
For proper operation of the Concealed Headlamp
System, refer to the Owner's Manual provided with
the vehicle.
The Concealed Headlamps are controlled by the Body
Controller (Fig. 1). Refer to Group 8E, Instrument
Panel for service procedures. The Body Controller re-
ceives input information from the ignition switch, head-
lamp switch, and the headlamp dimmer switch. The Body Controller also controls the headlamp doors
when the Passing Lights (manually flashing bright
lights) are used. With the headlamp switch turned off,
actuating the headlamp dimmer switch will signal the
Body Controller to open the headlamp doors. The oper-
ator then has two seconds to flash the bright lights be-
fore the Body Controller closes the headlamp doors.
Holding the headlamp dimmer switch in the engaged
position will signal the Body Controller to keep the
headlamp doors open until the dimmer switch is re-
leased. Actuating the headlamp dimmer switch with the
parking lamps ON signals the Body Controller to open
the headlamp doors and keep them open until the head-
lamp switch is turned off.
AY and AC vehicles use a single motor, centrally
located behind the radiator grille, and linked to the
headlamp doors by a torsion bar. Refer to Service
Procedures for more information. The headlamp door drive motors are equipped with
a manual override hand wheel to open or close the
headlamp doors if a failure should occur or servicing
is required. Access to the handwheel can be gained
through a flap covered hole in the sight shield be-
hind the bumper fascia, and under the hood. Several
revolutions of the handwheel may be required to
move the headlamp doors.
DIAGNOSTIC PROCEDURES
Before diagnosing a problem with the headlamp
doors, check for possible collision damage, binding,
improperly installed assemblies, or freezing weather
conditions. When diagnosing an electrical problem, refer to:
² The Concealed Headlamps Electrical Diagnosis
chart in this section.
² The Wiring Diagrams Manual.
² The Headlamp Doors System section of the appro-
priate Body Diagnostic Procedures Manual.
PROBLEM
One headlamp door is inoperative when the head-
lamp switch is ON and the ignition switch is in the
RUN position. The other headlamp door operates
normally.
AC OR AY-VEHICLE BODY CHECK:
² Headlamp door pivot and crank for seizure.
² Headlamp torsion bar sleeve or clip for excessive
wear or breakage.
² Headlamp door crank for missing or broken screw.
² Headlamp torsion bar for disengagement or break-
age.
PROBLEM
Headlamp door operates erratically.
CHECK:
² For freezing weather conditions.
² For excessive effort to move headlamp door pivots.
² For corrosion or improperly aligned components.
² For stripped motor reduction gears.
² For defective body controller. Refer to the Con-
cealed Headlamp Electrical Diagnosis chart in this
section. Also refer to the Wiring Diagrams Manual
and Body Diagnostic Procedures Manual.
Fig. 1 Body Controller
Ä LAMPS 8L - 27

FRONT IMPACT SENSORS
The driver air bag system is a safety device de-
signed to reduce the risk of fatality or serious injury,
caused by a frontal impact of the vehicle. The impact sensors provide verification of the di-
rection and severity of the impact. Three impact sen-
sors are used. One is called a safing sensor. It is
located inside the diagnostic module which is
mounted on the floor pan, just forward of the center
console. The other two sensors are mounted on the
upper crossmember of the radiator closure panel on
the left and right side of the vehicle under the hood. The impact sensors are threshold sensitive switches
that complete an electrical circuit when an impact
provides a sufficient G force to close the switch. The
sensors are calibrated for the specific vehicle and re-
act to the severity and direction of the impact.
CLOCKSPRING
The clockspring is mounted on the steering column
behind the steering wheel, and is used to maintain a
continuous electrical circuit between the wiring har-
ness and the driver's air bag module. This assembly
consists of a flat ribbon-like electrically conductive
tape which winds and unwinds with the steering
wheel rotation.
DIAGNOSTIC MODULE
The Air Bag System Diagnostic Module (ASDM)
contains the safing sensor and energy reserve capac-
itor. The ASDM monitors the system to determine
the system readiness. The ASDM will store sufficient
energy to deploy the air bag for only two minutes af-
ter the battery is disconnected. If both front impact
sensors are open the air bag could be deployed up to
9.5 minutes after the battery is disconnected. The
ASDM contains on-board diagnostics, and will illumi-
nate the AIR BAG warning lamp in the cluster when
a fault occurs.
STORAGE
The air bag module must be stored in its original
special container until used for service. Additionally,
it must be stored in a clean, dry environment, away
from sources of extreme heat, sparks, and sources of
high electrical energy. Always place or store the
module on a surface with the trim cover facing up to
minimize movement in case of accidental deploy-
ment.
HANDLING LIVE MODULE
At no time should any source of electricity be per-
mitted near the inflator on the back of the module.
When carrying a live module, the trim cover should
be pointed away from the body to minimize injury in
the event of accidental deployment. In addition, if
the module is placed on a bench or other surface, the plastic trim cover should be face up to minimize
movement in case of accidental deployment. When handling a steering column with an air bag
module attached, never place the column on the floor
or other surface with the steering wheel or module
face down.
DEPLOYED MODULE
The vehicle interior may contain a very small
amount of sodium hydroxide powder, a byproduct of
air bag deployment. Since this powder can irritate
the skin, eyes, nose or throat, be sure to wear safety
glasses, rubber gloves and long sleeves during
cleanup (Fig. 2).
If you find that the cleanup is irritating your skin,
run cool water over the affected area. Also, if you ex-
perience nasal or throat irritation, exit the vehicle
for fresh air until the irritation ceases. If irritation
continues, see a physician.
CLEANUP PROCEDURE
Begin the cleanup by putting tape over the two air
bag exhaust vents (Fig. 3) so that no additional pow-
der will find its way into the vehicle interior. Then
remove the air bag and air bag module from the ve-
hicle. Use a vacuum cleaner to remove any residual pow-
der from the vehicle interior. Work from the outside
in so that you avoid kneeling or sitting in a un-
cleaned area. Be sure to vacuum the heater and A/C outlets as
well (Fig. 4). In fact it's a good idea to run the blower
on low and to vacuum up any powder expelled from
the plenum. You may need to vacuum the interior of
the car a second time to recover all of the powder. Place the deployed bag and module in your auto-
motive scrap.
Fig. 2 Wear Safety Glasses and Rubber Gloves
8M - 2 RESTRAINT SYSTEMS Ä

SERVICE OF DEPLOYED AIR BAG MODULE
After an air bag has been deployed, the air bag
module and clockspring must be replaced because
they cannot be reused. Other air bag system compo-
nents are replaced if damaged.
SCHEDULED MAINTENANCE INSPECTION
Vehicles equipped with a Air Bag System must be
inspected every three years or 30,000 miles / 48,000
Km. The following items should be inspected. (1) Inspect components for damage or deteriora-
tion. (a) If the air bag module housing shows signs of
physical damage or abuse, replace the module. (b) Check that both front impact sensors are
properly installed to the upper crossmember of the
radiator closure panel. Repair as required.
(2) Check the air bag warning lamp for proper op-
eration as follows: (a) Turn ignition switch to the ON position, the
air bag warning lamp should light. If not, test the system using the DRB II and Passive Restraint
System Diagnostic Procedures Manual. Repair as
required.
(b) The air bag warning lamp lights, but fails to go
out after ten seconds. Test the system using the DRB
II and Passive Restraint System Diagnostic Proce-
dures Manual. Repair as required. (c) Erasing of fault codes is not required.
AIR BAG SYSTEM CHECK
WARNING: BEFORE BEGINNING ANY AIR BAG SYS-
TEM CHECK PROCEDURES, REMOVE AND ISOLATE
THE BATTERY NEGATIVE (-) CABLE (GROUND)
FROM THE VEHICLE BATTERY. THIS IS THE ONLY
SURE WAY TO DISABLE THE AIR BAG SYSTEM.
FAILURE TO DO THIS COULD RESULT IN ACCIDEN-
TAL AIR BAG DEPLOYMENT AND POSSIBLE PER-
SONAL INJURY.
WHEN AN UNDEPLOYED AIR BAG ASSEMBLY IS
TO BE REMOVED FROM THE STEERING WHEEL,
DISCONNECT BATTERY GROUND CABLE AND
ISOLATE. ALLOW SYSTEM CAPACITOR TO DIS-
CHARGE FOR TWO MINUTES, THEN BEGIN AIR
BAG REMOVAL. (1) Disconnect the battery negative cable and iso-
late. (2) Remove forward console or cover as necessary.
(3) Connect DRB II to ASDM diagnostic 6-way con-
nector, located at right side of module. (4) Turn the ignition key to ON position. Exit vehicle
with DRB II. Use the latest version of the proper
cartridge. (5) After checking that no one is inside the vehicle,
connect the negative battery cable. (6) Using the DRB II, read and record active fault
data. (7) Read and record any stored faults.
(8) Refer to the Passive Restraint Diagnostic Test
Manual if any faults are found in steps 6 and 7. (9) Erase stored faults if there are no active fault
codes. If problems remain, fault codes will not erase. (10) With the ignition key in the ON position, make
sure no one is in the vehicle. (11) From the passenger side of vehicle, turn the
ignition key to OFF then ON and observe the instru-
ment cluster air bag lamp. It should go on for 6 to 8
seconds, then go out; indicating system is functioning
normally. If air bag warning lamp either fails to light,
blinks on and off or goes on and stays on, there is
a system malfunction. Refer to the Passive Re-
straint Diagnostic Test Manual to diagnose the
problem.
Fig. 3 Seal the Air Bag Exhaust Vents
Fig. 4 Vacuum Heater and A/C Outlets
Ä RESTRAINT SYSTEMS 8M - 3

AIR BAG MODULE
WARNING: BEFORE BEGINNING ANY AIR BAG
SYSTEM REMOVAL OR INSTALLATION PROCE-
DURES, REMOVE AND ISOLATE THE BATTERY
NEGATIVE (-) CABLE (GROUND) FROM THE VEHI-
CLE BATTERY. THIS IS THE ONLY SURE WAY TO
DISABLE THE AIR BAG SYSTEM. FAILURE TO DO
THIS COULD RESULT IN ACCIDENTAL AIR BAG
DEPLOYMENT AND POSSIBLE PERSONAL INJURY. UNDEPLOYED AIR BAG REMOVAL FROM THE
STEERING WHEEL: DISCONNECT BATTERY
GROUND CABLE AND ISOLATE. ALLOW SYS-
TEM CAPACITOR TO DISCHARGE FOR TWO
MINUTES. BEGIN AIR BAG REMOVAL.
REMOVAL
When removing a deployed module, wear rubber
gloves, eye protection and a long sleeve shirt as de-
posits may be on the surface which could irritate the
skin and eyes. (1) Disconnect battery negative cable and isolate.
(2) Wait two minutes for the reserve capacitor to
discharge before removing undeployed module. (3) Remove four nuts attaching air bag module to
steering wheel (Fig. 5).
(4) Lift module, and disconnect electrical connector
from rear of module. (5) Remove module.
(6) When replacing a deployed module, the clock-
spring must also be replaced. Refer to Clockspring
Removal and Installation for proper procedure.
INSTALLATION
(1) Connect clockspring wiring connector to the
module, by pressing straight in on the connector. (2) Install four nuts and tighten to 9 to 11 N Im (80
to 100 in. lbs.) torque. (3) Do not connect battery negative cable. Refer to
Air Bag System Check for proper procedure.
LEFT FRONT IMPACT SENSOR
REMOVAL
WARNING: BEFORE BEGINNING ANY AIR BAG
SYSTEM REMOVAL OR INSTALLATION PROCE-
DURES, REMOVE AND ISOLATE THE BATTERY
NEGATIVE (-) CABLE (GROUND) FROM THE VEHI-
CLE BATTERY. THIS IS THE ONLY SURE WAY TO
DISABLE THE AIR BAG SYSTEM. FAILURE TO DO
THIS COULD RESULT IN ACCIDENTAL AIR BAG
DEPLOYMENT AND POSSIBLE PERSONAL INJURY. (1) Disconnect battery negative cable and isolate.
(2) Disconnect speed control servo from battery
tray, if equipped. (3) Remove battery, battery tray, powertrain con-
trol module and coolant bottle. (4) Disconnect impact sensor electrical connector.
(5) Remove three screws holding sensor to radiator
closure panel. Remove left sensor (Fig. 6).
INSTALLATION
(1) Mount left sensor (arrow pointed forward) to
engine side of closure panel using three screws pro-
vided with new sensor. Tighten to 10 to 13 N Im (90
to 120 in. lbs.) torque.
Fig. 5 Air Bag Module
Fig. 6 Left Impact Sensor
8M - 4 RESTRAINT SYSTEMS Ä