1993 CHEVROLET DYNASTY check engine

INOPERATIVE SYSTEM
If road test verifies an inoperative system with a
correct speedometer operation:
² Inspect fuse
² Check for loose electrical and vacuum connections
at the servo
² Check for correct position of the vacuum check
valve in the hose from servo to vacuum source. The
word VAC on the valve must point toward the vac-
uum source.
² Inspection should also be made to verify that both
ends of the vehicle speed control cable are securely
attached. If either end is loose, the vehicle speed con-
trol will be inoperative.
CHECKING FOR FAULT CODE
(1) When trying to verify a vehicle speed control
electronic malfunction: (a) Connect a DRB II if available.
(b) Plug DRB II into the diagnostic connector in
the engine compartment. (c) Check that either a Fault Code 34 or Fault
Code 15 is indicated. (d) An inoperative vehicle speed control may still
occur without either fault code being indicated. (e) With key inserted in ignition switch, cycle
switch to ON position three times. On third cycle,
leave switch in ON position. (f) After switch has been cycled three times, ob-
serve CHECK ENGINE indicator on instrument
cluster. If a Fault Code is present, indicator will
flash (blink) in a series which will show which
Fault Code is the problem. EXAMPLE: A series of
three flashes in rapid succession, a slight pause,
then four flashes in rapid succession would indicate
Fault Code 34.
(2) If no Fault Code appears, or Fault Code 34 is
observed, refer to:
² The Servo Electrical Test.
² The Powertrain Control Module Electrical Test.
(3) If a fault code 15 is observed, test vehicle speed
sensor. For testing vehicle speed sensor and related compo-
nents refer to the Powertrain Diagnostics Test Proce-
dure Manual. (4) Correct any problems found when performing
these tests and recheck for Fault Code if changes
were made. (5) If no problems were found above, replace pow-
ertrain control module.
VEHICLE SPEED CONTROL ELECTRICAL TESTS
WARNING: IF REMOVAL OF AIR BAG MODULE IS
NECESSARY, REFER TO GROUP 8M, RESTRAINT
SYSTEMS.
Fig. 6 Vehicle Speed ControlÐAC & AY Bodies with 2.5L
Ä VEHICLE SPEED CONTROL 8H - 3

(a) With brake pedal released, there should be
continuity:
² Between pin 1 and pin 4
² Between pin 3 and pin 6
² No continuity between pin 2 and pin 5
(b) With brake pedal depressed, there should be
no continuity:
² Between pin 1 and pin 4
² Between pin 3 and pin 6
² Continuity between pin 2 and pin 5
(2) If the above results are not obtained, the stop
lamp switch is defective or out of adjustment. (3) Stop lamp switch adjustment is detailed in
Group 5, Brakes.
VACUUM SUPPLY TEST
(1) Disconnect vacuum hose at the servo and in-
stall a vacuum gauge in the hose (Fig. 17).
(2) Start engine and observe gauge at idle. Vac-
uum gauge should read at least ten inches of mer-
cury. Shut off engine, the vacuum should continue to
hold 10 inches of mercury. (3) If vacuum does not meet this requirement,
check and correct the following vacuum leaks:
² Vacuum lines
² Check valve
² Vacuum reservoir
² Servo, refer to Servo Vacuum Test
² Poor engine performance
SERVO VACUUM TEST
(1) Remove the vehicle speed control cable at the
throttle body end. (2) Disconnect the 4-way electrical connector and
the vacuum harness at the servo (Refer to Fig. 12). (3) Connect battery voltage to pin 2 of the servo.
(4) Ground the remaining three servo pins 1, 3 and
4. (5) Connect a hand held vacuum pump to the servo
vacuum nipple and apply 10 to 15 inches of vacuum. (6) The cable should pull in and hold for as long as
vacuum is applied.
SERVO UNIT
REMOVAL
(1) Remove two nuts attaching vehicle speed con-
trol cable and mounting bracket to servo. (2) Remove screws attaching servo mounting
bracket. (3) Remove servo mounting bracket.
Fig. 15 Vehicle Speed Control Switch Continuity
Fig. 16 Stop Lamp and Vehicle Speed Control Switch Wiring
Fig. 17 Vacuum Gauge Test
Ä VEHICLE SPEED CONTROL 8H - 9

LAMPS
CONTENTS
page page
BULB APPLICATION TABLE ............... 38
CONCEALED HEADLAMPS ................ 27
EXTERIOR LAMP SWITCHES AND HEADLAMP ALIGNMENT ........................... 3
EXTERIOR LAMP SYSTEMS .............. 25
EXTERIOR LAMPSÐAA BODY ............. 7
EXTERIOR LAMPSÐAC BODY ............ 10 EXTERIOR LAMPSÐAG BODY
............ 14
EXTERIOR LAMPSÐAJ BODY ............ 16
EXTERIOR LAMPSÐAP BODY ............ 19
EXTERIOR LAMPSÐAY-BODY ............ 22
GENERAL INFORMATION .................. 1
ILLUMINATED ENTRY SYSTEM ........... 33
GENERAL INFORMATION
Each vehicle is equipped with lamps used for illumi-
nating and indicating purposes. A circuit must have a
good ground to be complete. Circuit ground occurs
when the lamp socket makes contact with the metal
body. On vehicles with plastic lamps, a wire between
the socket and the body makes the grounds. When changing lamp bulbs, check the socket for
corrosion. If corrosion is present, clean contacts with a
wire brush and coat the inside of the socket with
Mopar tMulti-purpose Grease or equivalent.
CAUTION: Do not touch the glass of halogen bulbs
with fingers or any possibly oily surface, reduced
bulb life will result.
BODY IDENTIFICATION
Throughout this Group, references are made to the
vehicle family or body code. To decode the vehicle
identification plates, refer to the Introduction Section
at the front of this manual.
DIAGNOSTIC PROCEDURES
Begin electrical system failure diagnosis by testing
all related fuses and circuit breakers in the fuse block
and engine compartment. When a vehicle experiences problems with the head-
lamp system, verify the condition of the battery con-
nections, charging system, headlamp bulbs, wire con-
nectors, relay, high beam dimmer switch and headlamp
switch. Refer to Wiring Diagrams manual for compo-
nent locations and circuit information.
SYMPTOM
Headlamps are dim when engine is idling of
with ignition turned OFF. Canada cars must
have lamps ON. ACTION
² Clean battery terminal clamps and posts. Refer to
Group 8B, Battery/Starter/Generator Service for
proper procedures.
² Test charging system output. Refer to Group 8A,
Battery/Starting/Charging Systems Diagnostics for
proper testing procedures.
² Test for high resistance in headlamp circuits.
² Defective headlamp bulb.
SYMPTOM
Bulbs burn out frequently.
ACTION
² Test charging system output. Refer to Group 8A,
Battery/Starting/Charging Systems Diagnostics for
proper testing procedures.
² Check for loose or corroded connector terminals or
splices in headlamp circuits. Refer to Wiring Diagrams
manual for component and splice locations.
SYMPTOM
Headlamps are dim with engine running above
idle. Canada cars must have lamps ON.
ACTION
² Test charging system output. Refer to Group 8A,
Battery/Starting/Charging Systems Diagnostics for
proper testing procedures.
² Test for high resistance in headlamp circuits.
² Defective headlamp bulb.
SYMPTOM
Headlamps flash randomly.
ACTION
² Test for poor circuit ground.
² Test for high resistance in headlamp circuits.
Ä LAMPS 8L - 1

BULB APPLICATION TABLE
GENERAL INFORMATION
The following Bulb Application Table lists the
lamp title in bold print on the left side of the column.
The vehicle family and model codes are listed under
the lamp title. The trade number or part number is
listed on the right side of the column.
CAUTION: Do not use bulbs that have a higher can-
dle power than the bulb listed in the Bulb Applica-
tion Table. Damage to lamp can result. Do not touch halogen bulbs with fingers or other
possibly oily surfaces. Bulb life will be reduced .
EXTERIOR LAMPS
Back-up
AY/C-P ....................................................................921
AA/D-A, AC/C, AY/C-S .........................................922
AA/P-P-C, AJ/C, AP/D-P.....................................1156
AA/P-H, AC/D, AG/V, AY/C-P ...........................3157
Center High Mounted Stop
AA ...........................................................................921
AC, AG, AJ, AY, AP ............................................922
Cornering
AA, AY .................................................................3157
Fog
AA ......................................................................GE880
AP/D...................................................................GE893
AG, AP/P .................................................................H3
Front Side Marker
AA/P-H, AA/D, AC, AJ, AP, AY-S......................168
AA/P-PX, AA/C, AY-P ....................................194NA
Front Side Marker/Turn Sig.
AG....................................................................3157NA
Headlamp/Aero
AG, AJ-High Beam .............................................9005
AG, AJ-Low beam ...............................................9006
AA, AC/D, AP ......................................................9004
Headlamp/Sealed Low Beam
AC/C, AY ...........................................................H4703
Headlamp/Sealed High Beam
AC/C, AY ...........................................................H4701
License Plate
AA, AC/C, AG, AJ, AP, AY/C-S ..........................168
AC/D, AY/C-P.........................................................194
Park/Turn Signal
AC/C-D, AY/C-P, AY/C-S ..............................3157NA
AA/P-X-C, AC/C, AG, AY/C-P, AY/C-S ........194NA
AA/P-H-D ..............................................................3157
AJ, AP...................................................................2057
Rear Side Marker
AC/C, AG, AJ, AY/C-S-P ......................................168
AA/P-C-D, AC/D, AP, AY/CS (opt.) .....................916
Tail
AG ...........................................................................168
AJ, AY/C-P .............................................................916 Tail Reflector
AY ...........................................................................168
Tail/Stop/Turn Signal
AP ..........................................................................2057
AG, AC..................................................................3057
AA, AJ, AY ..........................................................3157
INTERIOR LAMPS
Some components have lamps that can only be ser-
viced by a Authorized Service Center (ASC) after the
component is removed from the vehicle. Contact local
dealer for location of nearest ASC. Chrysler vehicles
are equipped with a mechanical instrument cluster
(MIC) or an optional electronic instrument cluster
(EIC). If a bulb is unique to the MIC or EIC the ac-
ronym will follow the title.
INDICATOR LAMPS
Service procedures for the indicator lamps in the
instrument cluster are located in Group 8E, Instru-
ment Panel and Gauges. Air Bag (MIC)
AC, AY....................................................................103
AA, AG, AJ, AP ...............................................PC194
Antilock (MIC)
AA ...........................................................................103
AC, AG, AJ, AP, AY .......................................PC194
Antilock (EIC)
AA, AY ..............................................................PC194
AJ ............................................................................103
Brake (MIC)
AA ...........................................................................103
AC, AG, AJ, AP, AY .......................................PC194
Brake (EIC)
AA, AY ..............................................................PC194
AJ ............................................................................103
Check Engine (MIC)
AA ...........................................................................103
AC, AG, AJ, AP, AY .......................................PC194
Check Engine (EIC)
AA, AY ..............................................................PC194
AJ ............................................................................103
Check Gauges
All .......................................................................PC194
Door Open
AA, AC, AY .............................................................74
AP ............................................................................161
AG, AJ ............................................................4437661
Fog Lamp (MIC)
AG ......................................................................PC194
High Beam (MIC)
AA ...........................................................................103
AC, AG, AJ, AP, AY .......................................PC194
High Beam (EIC)
AA, AY ..............................................................PC194
Lamp Outage
8L - 38 LAMPS Ä

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

(2) Connect sensor wiring lead from harness to
connector on body of sensor. (3) Install coolant bottle, powertrain control mod-
ule, battery tray and battery. (4) Install speed control servo to battery tray, if
equipped. (5) Do not connect negative battery cable. Refer to
Air Bag Systems Check for proper procedure.
RIGHT FRONT IMPACT SENSOR
REMOVAL
(1) Disconnect battery ground cable and isolate.
(2) Disconnect impact sensor electrical connector
(Fig. 7).
(3) Remove three screws holding sensor to radiator
closure panel. Remove right sensor.
INSTALLATION
(1) Mount right sensor (arrow pointed forward) to
engine side of closure panel using three screws pro-
vided with the new sensor. Tighten 10 to 13 N Im (90-
120 in. lbs.) torque. (2) Connect sensor wiring lead from harness to
connector on body of sensor. (3) Do not connect negative battery cable. Refer to
Air Bag Systems Check for proper procedure.
AIR BAG SYSTEM DIAGNOSTIC MODULE (ASDM)
WARNING: THE ASDM CONTAINS ONE OF THE IM-
PACT SENSORS WHICH ENABLE THE SYSTEM TO
DEPLOY THE AIR BAG. TO AVOID ACCIDENTAL
DEPLOYMENT, NEVER CONNECT ASDM ELECTRI- CALLY TO THE SYSTEM UNLESS IT IS BOLTED TO
VEHICLE. BEFORE BEGINNING ANY AIR BAG SYS-
TEM REMOVAL OR INSTALLATION PROCEDURES,
REMOVE AND ISOLATE THE BATTERY NEGATIVE
(-) CABLE (GROUND) FROM THE VEHICLE BAT-
TERY. THIS IS THE ONLY SURE WAY TO DISABLE
THE AIR BAG SYSTEM. FAILURE TO DO THIS
COULD RESULT IN ACCIDENTAL AIR BAG DE-
PLOYMENT, AND POSSIBLE PERSONAL INJURY.
REMOVAL
(1) Disconnect battery ground cable, and isolate.
(2) Remove forward console bezel (Fig. 8).
(3) Remove two screws from right side console be-
zel and remove bezel. (4) Disconnect wiring at ASDM.
(5) Remove module mounting screws, and remove
module.
INSTALLATION
(1) Position the ASDM with the arrow pointing
forward on the console reinforcement. Insert tab on
the ASDM in the slot on the reinforcement. (2) Attach the ASDM to the support bracket with
the screws supplied and tighten to 1.7 to 2 N In
(15-20 in. lbs.) torque. (3) Connect wiring at ASDM, making sure both
connectors are seated and locking tabs engaged. (4) Install right side console bezel.
(5) Install forward console bezel.
(6) Do not connect negative battery cable. Refer to
Air Bag System Check for proper procedure.
Fig. 7 Right Impact Sensor
Fig. 8 Air Bag System Diagnostic Module (ASDM)
Ä RESTRAINT SYSTEMS 8M - 5

(3) Activate the power door locks in both the
LOCK and UNLOCK directions. The horn will sound
after each activation. (4) Rotate the key in each of the door lock cylin-
ders to the unlock position. The horn will sound as
the switch closes, and again when it opens. There
must b e a 1 second delay between changing switch
states, or the horn will not sound.
² Press the LOCK button,horn will sound.
² Press the UNLOCK button, horn will sound.
(5) Cycle the key to the ignition RUN position. A
single horn pulse will indicate proper operation of
the ignition input. This will also take the module out
of the diagnostics mode. For any of these tests, if the
switch does not remain open or closed for at least 1
second, the horn will only sound once. The lack of a horn pulse, during any operation, in-
dicates a switch failure. Check for continuity at the
switch, if this is good, check for an open or shorted
wire between the switch and alarm module. Also,
check if a new powertrain control module has been
installed recently. Vehicle Theft Security System will
not function until 20 engine cranks. Whenever a Vehicle Theft Security System mal-
function occurs, first verify that the wire harness is
properly connected to all connectors before starting
normal diagnosis and repair procedures. Refer to Ve-
hicle Theft Security System Diagnosis Chart (Fig. 3).VEHICLE THEFT SECURITY SYSTEM MODULE
REPLACEMENT
If the Vehicle Theft Security System module is be-
ing removed and no replacement module is being in-
stalled, the module wiring must be disconnected
while the engine is running. Failure to do so will
cause a no-start condition (Fig. 3 and 4). (1) Remove lower right instrument panel silencer.
(2) Remove glove box assembly.
(3) Remove three attaching screws mounting the
bracket to instrument panel. (4) Lower bracket and module assembly, to discon-
nect wire connectors. (5) Remove the Remote keyless module so to have
access to the Security Module two screws attaching
module to bracket. (6) For installation reverse above procedures.
SECURITY SYSTEM HOOD SWITCH REPLACEMENT
(1) Remove screw from left inner fender (Fig. 5).
(2) Disconnect wiring.
(3) Remove switch.
(4) For installation reverse above procedures.
SECURITY SYSTEM DOOR SWITCH REPLACEMENT
(1) Remove door trim panel and water shield. Re-
fer to Group 23, Body.
Fig. 1 Vehicle Theft Security System Components
8Q - 2 VEHICLE THEFT SECURITY SYSTEM Ä

The MOPAR Silicone Rubber Adhesive Sealant
gasket material or equivalent should be applied in a
continuous bead approximately 3mm (0.120 inch) in
diameter. All mounting holes must be circled. For
corner sealing, a 3.17 or 6.35 mm (1/8 or 1/4 inch.)
drop is placed in the center of the gasket contact
area. Uncured sealant may be removed with a shop
towels. Components should be torqued in place while
the sealant is still wet to the touch (within 10 min-
utes). The usage of a locating dowel is recommended
during assembly to prevent smearing of material off
location.
CRANKSHAFT SPROCKET BOLT ACCESS PLUG
An Access plug is located in the right inner fender
shield. Remove the plug and insert proper size
socket, extension and rachet, when crankshaft rota-
tion is necessary.
ENGINE PERFORMANCE
If a loss of performance is noticed, ignition timing
should be checked. If ignition timing is retarded by
9, 18 or 27É indicating 1, 2 or 3 (timing belt or chain)
teeth may have skipped, then, camshaft and acces-
sory shaft timing with the crankshaft should be
checked. Refer to Engine Timing Sprockets and Oil
Seals of the Engine Section. To provide best vehicle performance and lowest ve-
hicle emissions, it is most important that the tune-up
be done accurately. Use the specifications listed on
the Vehicle Emission Control Information label
found in the engine compartment. (1) Test cranking amperage draw. See Starting
Motor Cranking Amperage Draw Electrical Section
of this manual. (2) Tighten the intake manifold bolts to specifica-
tions. (3) Perform cylinder compression test.(a) Check engine oil level and add oil if neces-
sary. (b) Drive the vehicle until engine reaches normal
operating temperature. (c) Select a route free from traffic and other
forms of congestion, observe all traffic laws, and ac-
celerate through the gears several times briskly.
CAUTION: Do not overspeed the engine. The higher
engine speed may help clean out valve seat deposits
which can prevent accurate compression readings.
(d) Remove all spark plugs from engine. As
spark plugs are being removed, check electrodes for
abnormal firing indicators fouled, hot, oily, etc.
Record cylinder number of spark plug for future
reference. (e) Disconnect coil wire from distributor and se-
cure to good ground to prevent a spark from start- ing a fire (Conventional Ignition System). For Direct
Ignition System DIS disconnect the coil connector. (f) Be sure throttle blade is fully open during the
compression check. (g) Insert compression gage adaptor into the #1
spark plug hole in cylinder head. Crank engine until
maximum pressure is reached on gage. Record this
pressure as #1 cylinder pressure. (h) Repeat Step G for all remaining cylinders.
(i) Compression should not be less than (689kPa)
100 psi and not vary more than 25 percent from
cylinder to cylinder. (j) If one or more cylinders have abnormally low
compression pressures, repeat steps 3b through 3h. (k) If the same cylinder or cylinders repeat an
abnormally low reading on the second compression
test, it could indicate the existence of a problem in
the cylinder in question.
The recommended compression pressures are
to be used only as a guide to diagnosing engine
problems. An engine should not be disassembled
to determine the cause of low compression un-
less some malfunction is present. (4) Clean or replace spark plugs as necessary and
adjust gap as specified in Electrical Group 8. Tighten to
specifications. (5) Test resistance of spark plug cables. Refer to
Ignition System Secondary Circuit Inspection Electri-
cal Section Group 8. (6) Inspect the primary wire. Test coil output volt-
age, primary and secondary resistance. Replace parts
as necessary. Refer to Ignition System and make nec-
essary adjustment. (7) Ignition timing should be set to specifications.
(See Specification Label in engine compartment). (8) Test fuel pump for pressure and vacuum. Refer to
Fuel System Group 14, Specifications. (9) The air filter elements should be replaced as
specified in Lubrication and Maintenance, Group 0. (10) Inspect crankcase ventilation system as out
lined in Lubrication and Maintenance, Group 0. For
emission controls see Emission Controls Group 25 for
service procedures. (11) Inspect and adjust accessory belt drives refer-
ring to Accessory Belt Drive in Cooling System, Group
7 for proper adjustments. (12) Road test vehicle as a final test.
HONING CYLINDER BORES
Before honing, stuff plenty of clean shop towels
under the bores, over the crankshaft to keep abrasive
materials from entering crankcase area. (1) Used carefully, the cylinder bore resizing hone
C-823 equipped with 220 grit stones, is the best tool for
this job. In addition to deglazing, it will reduce taper
and out-of-round as well as removing light
9 - 2 ENGINE Ä