warning CHEVROLET DYNASTY 1993 Service Manual

VEHICLE SPEED SENSOR TEST
For testing of the vehicle speed sensor and related
components using DRB II, refer to the appropriate
Powertrain Diagnostics Test Procedure Manual.
PRINTED CIRCUIT BOARD REPLACEMENT
(1) Remove cluster bezel.
(2) Remove instrument cluster.
(3) Remove tachometer drive module, if equipped.
(4) Remove six retaining screws (Fig. 18).
(5) Twist out all illumination and warning lamp
sockets. (6) Pull printed circuit board from cluster housing.
(7) For installation reverse above procedures. Posi-
tion printed circuit board on cluster housing, being
certain that all gauge pins are inserted correctly.
CLUSTER LAMP REPLACEMENT
Illumination Lamp Chart shows cluster as viewed
from rear. However, all lamps must be replaced by
removing cluster from instrument panel (Fig. 19).
SWITCH AND PANEL COMPONENT SERVICE
LOWER STEERING COLUMN COVER REPLACEMENT
(1) Disconnect park brake release rod from the
park brake handle. (2) Remove two screws attaching hood release (Fig.
20). (3) Remove fuse access door and remove steering
column cover attaching screw located directly above
the fuse block. (4) Remove six screws around outside of steering
column cover. (5) Remove steering column cover.
(6) For installation reverse above procedures.
CENTER MODULE LOWER COVER REPLACEMENT
(1) Open ash receiver and remove center module
bezel. (2) Remove module cover to instrument panel re-
taining screws (Fig. 20). (3) Remove module cover from vehicle.
(4) For installation reverse above procedures.
CENTER MODULE BEZEL REPLACEMENT
(1) Open ash receiver.
(2) Grip module bezel around outer edges and pull
rearward to release six spring-type retaining clips
(Fig. 20). (3) For installation position spring clips to instru-
ment panel and push firmly until seated. (4) Close ash receiver.
Fig. 17 Vehicle Speed Sensor Removal
Fig. 18 Printed Circuit Board
Fig. 19 Instrument Cluster Illumination Lamps
Ä INSTRUMENT PANEL AND GAUGES 8E - 67

COMPACT DISC PLAYER
WARNING: USE OF THE CONTROLS, ADJUST-
MENTS, OR SERVICE PROCEDURES NOT SPECI-
FIED HERE OR IN THE OWNER MANUAL MAY
RESULT IN HAZARDOUS RADIATION EXPOSURE.
REPAIR PROCEDURES SHOULD ONLY BE PER-
FORMED BY A TRAINED TECHNICIAN.
DIAGNOSIS TEST
Power to the compact disc player is supplied by the
radio through the CD interface cable. The compact
disc player will only work with the radio system
turned ON. When a compact disc is inserted with the
label side facing up, the disc is automatically loaded
and will begin to play. The CD player may eject the disc with a display of
E under the following conditions:
² The surface of the disc is dirty or wet
² The disc was inserted with the label side facing
down
² The disc is defective
² The CD player may skip or mute while playing a
disc under severe vibration conditions example pot
holes, railroad tracks, etc.
² If the CD player becomes too hot at temperatures
above 60ÉC (140 ÉF) the CD player will shut down
with a display of HOT until it cools down. Refer to
the Audio Diagnostic Charts.
COMPACT DISC PLAYER REPLACEMENT
With intergral compact disc player refer to Radio
Removal.
AJ BODY
(1) Remove center instrument panel bezel by pull-
ing toward the rear of the car. (2) Remove two screws attaching disc player to
console (Fig. 36). (3) Pull disc player out of console and disconnect
interface cable. (4) To install compact disc player, above the re-
moval procedures.
Fig. 36 Compact Disc Player
8F - 30 AUDIO SYSTEM Ä

HORNS
CONTENTS
page page
GENERAL INFORMATION .................. 1
HORN SWITCH REPLACEMENT ............ 3 TESTING HORN SYSTEM
................. 1
GENERAL INFORMATION
WARNING: ON VEHICLES EQUIPPED WITH AIR
BAG, SEE GROUP 8M, RESTRAINT SYSTEMS FOR
STEERING WHEEL OR COLUMN REMOVAL PROCE-
DURES.
The horn circuit consists of a horn switch, horn re-
lay, and horns. The horn circuit feed is from the fuse
box to the number 1 terminal on the horn relay.
When the horn switch is depressed, this completes
the circuit to ground. This activates the horn relay
and an set of contacts in the relay to close, which al-
lows current to flow to the horn(s). The horn ground
wire is attached to the headlamp ground screw (Fig.
1).
TESTING HORN SYSTEM
HORNS WILL NOT SOUND
If the horns do not sound, check for a blown horn
fuse in the fuse block. If the fuse is blown, replace it
with the same fuse type. If the horns fail to sound
and the new fuse blows when depressing the horn
switch, a short circuit in the horn or the horn wiring
between the fuse terminal and the horn is responsi-
ble. If the fuse is good, disconnect wire connector at
horn. Using an test lamp, connect one lead to the
negative terminal and the other to the positive ter-
minal (Fig. 2). Depress the horn switch, the test
lamp should illuminate. If not connect the test lamp wire to a good ground and depress the horn switch. If
test lamp lights inspect ground wire circuit and re-
pair as needed.
If the test lamp fails to illuminate, check for a de-
fective horn relay. Substituting a known good horn
relay in the circuit. If the test lamp illuminates
when depressing the horn switch, the original relay
is defective. If the test lamp fails to illuminate with
a known good relay, unplug that relay. Connect a
jumper wire from the battery terminal to the horn
terminal on the relay terminal board (Fig. 3, 4, or 5).
If the test lamp connected in place of the horns, fails
to illuminate an open circuit in the wiring between
the relay terminal and the horn switch is at fault re-
pair as necessary.
HORNS SOUND CONTINUOUSLY
CAUTION: Continuous sounding of horns may
cause relay to fail.
Should the horns sound continuously, unplug the
horn relay from the terminal board inside the pas-
senger compartment. Plug in a known good relay. If
the horns stop blowing, relay is defective and must
be replaced. Should the horns still sound, proceed as
follows: Connect one voltmeter lead to battery termi-
nal on relay board and the other lead to switch ter-
minal. Refer to Figs. 6, 7, or 8. Voltmeter will
Fig. 1 Conventional Horn System
Fig. 2 Horn and Connector
Ä HORNS 8G - 1

Remove steering wheel horn pad and disconnect
wire from horn switch. Repeat the above test and if
the test lamp still illuminates, wire is shorted and
should be repaired. If test lamp does not illuminate,
horn switch is defective and must be replaced.
DIAGNOSIS TESTING
Horn does not sound, horn sounds intermittently,
or horn sounds continuously go to Horn Diagnosis
Chart (Fig. 9).
HORN SWITCH REPLACEMENT
WARNING: BEFORE BEGINNING ANY AIR BAG
SYSTEM REMOVAL OR INSTALLATION PROCE-
DURES, REMOVE AND ISOLATE THE NEGATIVE (-)
BATTERY CABLE (GROUND) FROM THE VEHICLE
BATTERY. THIS IS THE ONLY SURE WAY TO DIS-
ABLE THE AIR BAG SYSTEM. FAILURE TO DO
THIS COULD RESULT IN ACCIDENTAL AIR BAG
DEPLOYMENT AND POSSIBLE PERSONAL INJURY. (1) Disconnect and isolate negative battery cable
in engine compartment. (2) Remove four retaining nuts from back of steer-
ing wheel. Remove air bag module (Fig. 10 and 11). (a) Disconnect wire from rear of air bag module.
(b) Place air bag module on a clean level surface
with pad facing upward.
(3) Remove horn switch assembly from steering
wheel. (a) On luxury steering wheel (Fig. 10), pry out
two trim cover buttons on back of steering wheel to
access retaining screws for the horn switch. The
sport steering wheel (Fig. 11) the horn screws are
accessible after the Air Bag is removed. (b) Remove two screws and disconnect horn wires
located in the lower portion of steering wheel. Feed
wires through the access ports and remove horn
switch.
(4) For installation reverse the above procedures.
Use caution not to pinch wires.
Fig. 8 Testing Horn for Continuous SoundÐ AP and AA Bodies
Fig. 7 Testing for Short to GroundÐAC and AY Bodies
Ä HORNS 8G - 3

VEHICLE SPEED CONTROL
CONTENTS
page page
CHECKING FOR FAULT CODE .............. 3
DIAGNOSIS PROCEDURES ................ 2
GENERAL INFORMATION .................. 1
INOPERATIVE SYSTEM ................... 3
POWERTRAIN CONTROL MODULE ELECTRICAL TEST ................................ 5
ROAD TEST ............................ 2
SERVO ELECTRICAL TESTS ............... 4
SERVO UNIT ............................ 9 SERVO VACUUM TEST
................... 9
STOP LAMP VEHICLE SPEED CONTROL SWITCH TEST ......................... 8
VACUUM SUPPLY TEST .................. 9
VEHICLE SPEED CONTROL SWITCH REMOVAL ........................... 10
VEHICLE SPEED CONTROL SWITCH TEST . . . 8
VEHICLE SPEED CONTROL ELECTRICAL TESTS ............................... 3
GENERAL INFORMATION
The vehicle speed control is electronically con-
trolled and vacuum operated. The electronic control
is integrated into the powertrain control module, lo-
cated next to battery. The controls are located on the
steering wheel and consist of the ON/OFF, RESUME/
ACCEL and SET/DECEL buttons (Fig. 1). For iden-
tification and location of the major components (Fig.
2 through 8).
The system is designed to operate at speeds above
35 mph (50 km/h).
WARNING: THE USE OF VEHICLE SPEED CON-
TROL IS NOT RECOMMENDED WHEN DRIVING
CONDITIONS DO NOT PERMIT MAINTAINING A
CONSTANT SPEED, SUCH AS IN HEAVY TRAFFIC
OR ON ROADS THAT ARE WINDING, ICY, SNOW
COVERED, OR SLIPPERY.
TO ACTIVATE: The ON/OFF button to the de-
pressed latched position, ON, the vehicle speed con-
trol function is now ready for use. TO DEACTIVATE:
A soft tap of the brake pedal,
normal brake application or depressing the clutch
pedal while the system is engaged will disengage ve-
hicle speed control without erasing memory. A sud-
den increase in engine rpm may be experienced if the
clutch pedal is depressed while the vehicle speed con-
trol is engaged. Pushing the ON/OFF button to the
unlatched position or turning off the ignition erases
the memory. TO SET SPEED: When the vehicle has reached
the desired speed push the SET/DECEL button to en-
gage system which will then automatically maintain
the desired speed. TO DECELERATE: When vehicle speed control is
engaged, holding the SET/DECEL button depressed
allows the vehicle to coast to a lower speed setting.
Fig. 1 Vehicle Speed Control Switch
Fig. 2 Vehicle Speed ControlÐ2.2L and 2.5L
Ä VEHICLE SPEED CONTROL 8H - 1

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

Electronic vehicle speed control may be tested us-
ing two different methods. One involves use of a
DRB II. If this test method is desired, refer to the
Powertrain Diagnostic Test Procedures for charging
and vehicle speed control manual. The other test method uses a volt/ohm meter and is
described in the following tests. If any information is needed concerning wiring, re-
fer to Group 8W, Wiring Diagrams.
CAUTION: When test probing for voltage or conti-
nuity at electrical connectors, care must be taken
not to damage connector, terminals, or seals. If
these components are damaged, intermittent or
complete system failure may occur.
SERVO ELECTRICAL TESTS
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAG, SEE GROUP 8M, RESTRAINT SYSTEMS FOR
AIRBAG, STEERING WHEEL OR COLUMN RE-
MOVAL PROCEDURES.
(1) Turn ignition switch to the ON position. With
the vehicle speed control switch in the ON position,
set up a voltmeter to read battery voltage and con-
nect the negative lead to a good chassis ground. (2) Disconnect the four-way connector going to the
servo (Fig. 12). Test pin 2 of the main harness four-
way connector for battery voltage. If not OK go to
step 3. If voltage is OK go to step 4. (3) Perform the following tests.(a) Disconnect the six-way connector at the stop
lamp switch and test pin 1 of the main harness for
battery voltage. If voltage is OK perform the stop
lamp switch test. (b) If the stop lamp switch tests OK; repair wire
between the servo and the stop lamp switch. (c) If no voltage at pin 1 at the 6-way stop lamp
connector, remove the vehicle speed control switch
and disconnect the four-way connector. Test pin 1
of main harness for battery voltage. (d) If voltage is OK perform the vehicle speed
control switch test. (e) If vehicle speed control switch is OK, test
continuity across the clockspring. (f) If clockspring OK, repair as required, wire be-
tween stop lamp switch and clockspring. (g) If no voltage at pin 1 of the 4-way vehicle
speed control switch connector.
² Test for battery voltage between the ignition and
the fuse
² If voltage OK, check fuse
² If fuse OK, repair wire between fuse and clock-
spring
Fig. 7 Vehicle Speed ControlÐAC & AY Bodies with 3.0L
8H - 4 VEHICLE SPEED CONTROL Ä

(4) Connect a jumper wire between pin 2 of the
four-way servo connector of the main harness and
pin 2 of the vehicle speed control servo (Fig. 12). The
other three pins from the servo should show battery
voltage. If not, replace the servo. (5) Using an ohmmeter, connect one lead to a good
body ground and the other lead touch pin 1 in the
four-way servo connector of the main harness. The
meter should show continuity. If not, repair the
ground circuit as necessary.
POWERTRAIN CONTROL MODULE ELECTRICAL
TEST
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAG, SEE GROUP 8M, RESTRAINT SYSTEMS FOR
AIRBAG, STEERING WHEEL OR COLUMN RE-
MOVAL PROCEDURES.
(1) Unplug 60-way connector from the powertrain
control module, located next to the battery (Fig. 13). (2) Remove vehicle speed control switch. Refer to
Vehicle Speed Control Switch Removal. Disconnect
the 4-way connector. (3) Using an ohmmeter test continuity between pin
23 of powertrain control module and pin 4 of the ve-
hicle speed control switch harness. Refer to Fig. 14
for controller terminal locations. (a) If no continuity, repair wire circuit as neces-
sary. (b) Continuity OK, refer to Vehicle Speed Con-
trol Switch Test.
(4) Connect the 4-way connector to vehicle speed
control switch. (5) Connect negative lead of voltmeter to a good
body ground near the powertrain control module. (6) Turn ignition switch ON.
(7) Place vehicle speed control switch in the OFF
position. Touch the positive lead of the voltmeter to
pin 53, the voltmeter should read 0 volts. (8) Place vehicle speed control switch in the ON
position. Touch the positive lead of the voltmeter to
pin 53, the voltmeter should read battery voltage. (9) If no voltage, repair the wire between pin 53
and pin 3 of the vehicle speed control servo (Fig. 6).
If voltage is OK go to step 8. (10) Place vehicle speed control switch in the OFF
position. Touch the positive lead of the voltmeter to
pin 33, voltmeter should read 0 volts. (11) Place vehicle speed control switch in the ON
position. Touch the positive lead of the voltmeter to
pin 33, the voltmeter should read battery voltage. (12) If no voltage, repair the wire between pin 33
and pin 4 of the vehicle speed control servo (Fig. 6).
If voltage is OK go to step 11.
Fig. 8 Vehicle Speed ControlÐAC & AY Bodies with 3.3/3.8L
Ä VEHICLE SPEED CONTROL 8H - 5

meter should show continuity. If no continuity per-
form the following test. Continuity OK, go to step 12.(a) Using an ohmmeter test continuity between
pin 29 of powertrain control module and pin 3 of
the stop lamp switch connector. (b) If no continuity, repair as necessary.
(c) If continuity, refer to Stop Lamp Switch Test.
(d) If stop lamp switch test OK, Test continuity
between pin 6 of stop lamp switch and ground.
(14) Using an ohmmeter, touch one lead to a good
body ground and touch the other lead to pin 30. The
meter should show no continuity when transmission
is in DRIVE and continuity when in PARK or NEU-
TRAL. If not test Neutral Start and Back-Up switch
using DRB II.
VEHICLE SPEED CONTROL SWITCH TEST
WARNING: IF REMOVAL OF AIR BAG MODULE IS
NECESSARY, REFER TO GROUP 8M, RESTRAINT
SYSTEMS.
(1) Remove the switch and disconnect 4-way con-
nector. (2) Using an ohmmeter, test continuity at the four
pins of the vehicle speed control switch. Refer to Ve-
hicle Speed Control Switch Continuity (Fig. 15). (3) If there is no continuity or incorrect continuity
at any one of the switch positions, replace the switch.
STOP LAMP VEHICLE SPEED CONTROL SWITCH
TEST
(1) Disconnect the six way connector at the stop
lamp switch (Fig.16). Using an ohmmeter, continuity
may be checked at the switch side of the connector as
follows:
Fig. 11 Vehicle Speed Control Circuit
Fig. 12 Servo Harness Connector
Fig. 13 Powertrain Control Module and Connector Location
Fig. 14 Powertrain Control Module 60-WayConnector Shown from Terminal End
8H - 8 VEHICLE SPEED CONTROL Ä

(4) Disconnect electrical connector and vacuum
hose. (5) Pull cable away from servo to expose retaining
clip and remove clip attaching cable to servo.
INSTALLATION
(1) With throttle in full open position align hole in
vehicle speed control cable sleeve with hole in servo
pin and install retaining clip. (2) Connect vacuum hose to servo.
(3) Connect electrical connector.
(4) Position mounting bracket and install screws
attaching bracket and tighten to 12 N Im (105 in.
lbs.) torque. (5) Insert servo studs through holes in vehicle
speed control cable and mounting bracket. (6) Install nuts, tighten to 7 N Im (60 in. lbs.)
torque.
VEHICLE SPEED CONTROL SWITCH REMOVAL
The vehicle speed control switch is mounted in the
steering wheel and wired through the clock spring
device under the steering wheel hub (Fig.1).
WARNING: IF REMOVAL OF AIR BAG MODULE IS
NECESSARY, REFER TO GROUP 8M, RESTRAINT
SYSTEMS.
REMOVAL
(1) Turn off ignition.
(2) Remove two screws from back side of steering
wheel. (3) Rock switch away from air bag or horn pad
while lifting switch out of steering wheel. (4) Disconnect 4-way electrical connector.
INSTALLATION
(1) Turn off ignition.
(2) Connect 4-way electrical connector from clock
spring to switch. (3) Place switch in steering wheel, sliding the for-
ward edge of switch under air bag or horn pad. Line
up locating pins on switch with holes in steering
wheel frame. (4) Attach switch to wheel with two screws start-
ing with the screw at the left end of the switch.
8H - 10 VEHICLE SPEED CONTROL Ä