1993 CHEVROLET DYNASTY sensor

SPEEDOMETER ODOMETER ASSEMBLY REPLACEMENT
(1) Remove cluster bezel and mask/lens.
(2) Remove volt gauge.
(3) Remove screws attaching gauge assembly to
cluster. (4) Pull speedometer rearward to disengage from
gauge pins.
(5) For installation: Position speedometer on gauge
pins and push firmly until seated and reverse above
procedures.
SPEEDOMETER CIRCUIT TESTING
(1) Using the DRB II, check vehicle speed sensor
for fault code and for proper speed indication. Refer
to Powertrain Diagnostics Procedure Manual, Speed
Control System Test. (2) Remove speedometer from cluster.
(3) With ignition on check for battery voltage
across ignition and ground pins (Fig. 24). (4) Check for continuity from vehicle speed sensor
signal pin to connector at speed sensor.
VEHICLE SPEED SENSOR REPLACEMENT
(1) Remove harness connector from sensor and
make sure the weather seal is on harness connector
(Figs. 25 and 26). (2) Remove sensor retaining bolt.
(3) Pull sensor and pinion gear assembly out of
transaxle. If necessary, carefully pry loose with a flat
blade screwdriver. (4) Remove pinion gear from sensor.
Fig. 22 Cluster with Mask and Lens Removed
Fig. 23 Speedometer Diagnosis
Ä INSTRUMENT PANEL AND GAUGES 8E - 31

(5) For installation reverse above procedures. Seat
sensor assembly by hand to insure proper gear en-
gagement. Tighten retaining bolt to 7 N Im (60 in.
lbs.) torque.
ELECTRONIC AUTOMATIC TRANSAXLE VEHICLE SPEED SENSOR REPLACEMENT
The output vehicle speed sensor is located to the
left of the manual shift lever. (1) Raise and support vehicle on safety stands.
(2) Remove vehicle speed sensor (Fig. 27).
(3) For installation, reverse above procedures.
VEHICLE SPEED SENSOR TEST
For testing of the vehicle speed and related compo-
nents, refer to the Powertrain Diagnostics Test Pro-
cedure Manual.
PRINTED CIRCUIT BOARD REPLACEMENT
(1) Remove cluster assembly, refer to Cluster As-
sembly Replacement. (2) Twist out all lamp sockets.
(3) Remove screws securing printed circuit board
to cluster housing (Fig. 11). (4) Pull printed circuit board straight out and
avoid bending the board. (5) For installation reverse above procedures. Be
sure that all gauge pins are carefully aligned.
CLUSTER LAMPS REPLACEMENT
All cluster lamps are one-piece lamp and socket as-
semblies. Can be replaced by removing cluster as-
sembly from instrument panel. Replace appropriate
lamp shown in rear view of cluster (Fig. 28).
Fig. 24 Speedometer Pins
Fig. 25 Vehicle Speed Sensor and Connector
Fig. 26 Vehicle Speed Sensor and Speedometer Pinion
Fig. 27 Vehicle Speed Sensor Removal
8E - 32 INSTRUMENT PANEL AND GAUGES Ä

ELECTRONIC CLUSTER
SELF DIAGNOSTIC SYSTEM
The electronic clusters have an internal diagnostics
routing to isolate problems within the cluster or CCD
Bus. Using the cluster Self-Diagnostic Test will deter-
mine whether the problem is within the cluster or
outside of cluster (Fig. 29 and 30). Successful completion of the Self Diagnostic Test
indicates that the problem is in the CCD Bus, inter-
facing modules, connectors, or sensors outside of the
cluster. Refer to Fig. 31 for terminal listing.
CONDITION: CLUSTER DISPLAYS DO NOT ILLUMINATE AFTER VEHICLE IS STARTED
PROCEDURE
(1) Check fuses and verify battery and ignition
voltage at cluster connector. (2) Check ground from cluster connector to instru-
ment panel ground stud.
CONDITION: CLUSTER ASTERISK (*) FLASHES, CLUSTER DISPLAYS NOTINDICATING CORRECT DATA.
PROCEDURE
CCD bus problem. Use the Body Chassis Diagnos-
tic Manual to diagnose CCD Bus.
CONDITION: SPEEDOMETER AND ODOMETER ARE INOPERATIVE OR OPERATESINTERMITTENTLY
PROCEDURE
(1) If speedometer reads 0, or odometer is blank,
and cluster asterisk is flashing, use the Body Chassis
Diagnostic Manual to diagnose CCD Bus problem. (2) If cluster asterisk is not flashing, check for de-
fective vehicle speed sensor or speed sensor wiring.
CONDITION: OIL GAUGE, FUEL GAUGE, TEMPERATURE GAUGE, OR VOLTAGE GAUGEINOPERATIVE
PROCEDURE
If any gauge gives no indication and cluster aster-
isk is flashing, use the Body Chassis Manual to diag-
nose CCD Bus problem. If cluster asterisk is not flashing:
(1) Check for defective sending unit or wiring. (a) Sending units and wiring can be checked by
grounding the connector leads, at the sending unit,
in the vehicle. (b) With the ignition in the ON position, a
grounded input will cause the oil, fuel, or temper-
ature gauge to read maximum. (2) If the problem is with the oil, temperature, or
fuel gauge, check the body controller. If the problem
is with the voltage gauge, check the powertrain con-
trol module operation.
CONDITION: CLUSTER DISPLAY DOES NOT DIM WHEN HEADLAMP SWITCH ISACTIVATED AND RHEOSTAT ROTATED
PROCEDURE
If the cluster asterisk is flashing, Refer to the Body
Chassis Diagnostic Manual to diagnose the CCD Bus. If the cluster asterisk is not flashing:
(1) Check fuses in headlamp circuit.
(2) Check for loose connections or defective wiring
for headlamp switch to body controller. (3) Check for defective headlamp switch. The elec-
tronic instrument cluster receives the display inten-
sity status from the body controller via the CCD Bus.
CONDITION: SEAT BELT WARNING LAMP DOES NOT ILLUMINATE
PROCEDURE
Turn on ignition. Lamp should illuminate for six
seconds. If not: (1) Check for burned out lamp and retest.
(2) Replace cluster.
CONDITION: LOW WASHER, DOOR/DECK, OR MALFUNCTION INDICATOR (CHECK ENGINE)LAMP, DO NOT ILLUMINATE
PROCEDURE
(1) Perform cluster self-diagnostics to determine if
lamp will illuminate. If lamp does not, check for
burned out lamp, replace and retest. (2) If cluster asterisk is flashing, Refer to the Body
Chassis Diagnostic Manual to diagnose CCD Bus. (3) If cluster asterisk is not flashing:(a) For low washer fluid or door/deck, check in-
puts to body controller. (b) For malfunction indicator (check engine),
check powertrain control module operation.
CONDITION: ODOMETER DISPLAY IS BLANK. THE ODOMETER VALUE IS NO LONGERRETAINED IN THIS ELECTRONIC CLUSTER.THIS TAKES PLACE IN THE BODYCONTROLLER
PROCEDURE
(1) If cluster asterisk is flashing, Refer to the Body
Chassis Diagnostic Manual to diagnose CCD Bus. (2) If cluster asterisk is not flashing, perform clus-
ter self-diagnostics. If code 921 appears in the odom-
eter display, replace body controller for odometer
failure.
8E - 34 INSTRUMENT PANEL AND GAUGES Ä

AG AND AJ BODIES INDEX
page page
Cigar Lighter Removal ..................... 55
Cluster and Gauge Service and Testing ....... 43
Electronic Cluster ........................ 50
Electronic Vehicle Information Center (EVIC) .... 42
Engine Compartment Node ................. 55
Gauges ................................ 44 General Information
....................... 42
Instrument Panel Roll Down Procedure ........ 56
Interior Lamp Removal .................... 57
Mechanical/Electronic Cluster Removal ........ 43
Switch and Panel Component Service ......... 51
Switch Pod Assembly Removal .............. 43
GENERAL INFORMATION
CONVENTIONAL INSTRUMENT CLUSTER
The conventional instrument cluster incorporates
magnetic type gauges (Fig. 1).
The readings are only accurate when the ignition
switch is in the ON position.
TACHOMETER DRIVE MODULE
The tachometer drive module is an electronic mod-
ule used to drive a magnetic tachometer in a conven-
tional instrument cluster.
MESSAGE CENTER
The message center provides the driver with infor-
mation in addition to the standard vehicle instru-
mentation. A bezel will light up with door ajar,
washer fluid, deck ajar and alarm set information.
For vehicles without message center a plain bezel is
used.
ELECTRONIC VEHICLE INFORMATION CENTER
(EVIC)
The Electronic Vehicle Information Center is a
computer controlled warning system which, monitors
various sensors used on the vehicle. The system sup-
plements the warning indicators in the instrument
cluster. Visual warning messages are displayed by a
digital display (Fig. 2). Refer to Group 8C, Overhead
Console.
ELECTRONIC INSTRUMENT CLUSTER
The electronic instrument cluster uses vacuum flu-
orescent displays to display:
² Oil pressure
² System voltage
² Engine temperature
² Fuel level
² Speedometer and tachometer readings as well as
all warning indicators. The electronic cluster is eas-
ily distinguished from the conventional cluster by its
digital and linear display (Fig. 3.
ELECTRONIC CLUSTER DIMMING
The electronic cluster display is dimmed from day-
time to nighttime intensity when the head]lamp
switch is turned on. This intensity can be controlled
using the headlamp switch sliding rheostat. An additional detent on the headlamp switch rheo-
stat will allow daytime intensity while driving with
headlamps ON in daytime.
Fig. 1 Conventional Instrument Cluster
Fig. 2 EVIC
Fig. 3 Electronic Instrument Cluster
8E - 42 INSTRUMENT PANEL AND GAUGES Ä

helper depresses brake pedal and observes warning
lamp. If lamp fails to light, inspect for a burned out
lamp, disconnected socket, a broken or disconnected
wire at switch.If lamp is not burned out and wire continuity is
proven, replace brake warning switch in brake line
TEE fitting mounted on frame rail in engine com-
partment below master cylinder (Fig.16).
CAUTION: If wheel cylinder bleeder was opened
check master cylinder fluid level.
SPEEDOMETER SYSTEM
The vehicles are equipped with electronically
driven speedometer and odometer assemblies. The
unit has the same appearance as a conventional
speedometer but it eliminates the cable-driven me-
chanical system. A signal is sent from a transmis-
sion-mounted vehicle speed sensor to the
speedometer circuitry through the wiring harness.
By eliminating the speedometer cable, instrument
cluster service and removal is improved. Refer to Fig.
17 Speedometer Diagnosis Chart. When the speedometer is out of calibration. The
electronic automatic transaxle vehicle speed sensor
output must be calibrated to reflect the different combinations of equipment. The procedure is called
Pinion Factor, refer to Group 21, Transaxle for the
procedure.
Fig. 15 Brake System Warning Lamp Diagnosis
Fig. 16 Brake Warning Lamp Switch
8E - 48 INSTRUMENT PANEL AND GAUGES Ä

SPEEDOMETER/ODOMETER ASSEMBLY REMOVAL
(1) Remove switch pod assembly.
(2) Remove cluster, refer to Cluster Removal.
(3) Remove mask and lens assembly.
(4) Remove tachometer, turbo gauge.
(5) Remove volt, temperature, oil and fuel gauge
assemblies. (6) Remove the speedometer/odometer assembly
from the cluster housing. (7) Disconnect pigtail connector from the cluster
printed circuit board. (8) For installation reverse above procedures. Lis-
ten for the pigtail connector to snap in place.
SPEEDOMETER CIRCUIT TESTING
(1) Using DRB II, check vehicle speed sensor for
speed sensor fault code and for proper speed indica-
tion. Refer to Powertrain Diagnostics Procedure
Manual; Speed Control Test (Fig. 18). (2) Remove cluster, but do not disconnect cluster
wiring. (3) With ignition ON check for battery voltage
across the ignition pin and ground pin of speedome-
ter connector. (4) Check for continuity from vehicle speed sensor
signal pin to connector at speed sensor. (5) Check cluster to body for continuity to ground.
(6) If all these tests prove good, replace speedome-
ter.
VEHICLE SPEED SENSOR REPLACEMENT
(1) Remove harness connector from sensor and
make sure weather seal is on harness connector. (2) Remove sensor retaining bolt (Fig. 19).
(3) Pull sensor and pinion gear assembly out of
transaxle. If necessary carefully pry loose with a flat
blade screwdriver (Fig. 20). (4) Remove pinion gear from sensor.
(5) For installation reverse above procedures. Seat
the sensor assembly by hand to ensure proper gear
engagement. Tighten retaining bolt to 7 N Im (60 in.
lbs.) torque.
ELECTRONIC AUTOMATIC TRANSAXLE VEHICLE SPEED SENSOR REPLACEMENT
The output vehicle speed sensor is located to the
left of the manual shift lever. (1) Raise and support vehicle on safety stands.
(2) Remove vehicle speed sensor (Fig. 21).
(3) For installation, reverse above procedures.
Fig. 17 Speedometer Diagnosis
Fig. 18 Speedometer
Ä INSTRUMENT PANEL AND GAUGES 8E - 49

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.
TACHOMETER DRIVE MODULE REMOVAL
(1) Remove cluster assembly.
(2) Pull tachometer drive module from printed cir-
cuit board (Fig. 22). (3) For installation reverse above procedures. Use
care when aligning module to printed circuit board.
PRINTED CIRCUIT BOARD REMOVAL
(1) Remove cluster assembly.
(2) Remove mounting screws securing printed cir-
cuit board to cluster housing. (3) Remove tachometer drive module (Fig. 22).
(4) Twist out all lamp sockets.
(5) For installation reverse above procedures.
CLUSTER LAMPS REMOVALÐMECHANIALCLUSTER ONLY
(1) Remove cluster assembly (Fig. 23).
(2) Remove one piece integral lamp and socket
from rear of cluster.
ELECTRONIC CLUSTER
Refer to Body Diagnostic Procedures Manual when
using DRB II.
SELF DIAGNOSTIC SYSTEM
The electronic clusters have an internal diagnostic
routing to isolate problems within the cluster.
Fig. 20 Vehicle Speed Sensor and Speedometer Pinion
Fig. 21 Vehicle Speed Sensor Removal
Fig. 22 Cluster Printed Circuit Board
Fig. 19 Vehicle Speed Sensor and Connector
8E - 50 INSTRUMENT PANEL AND GAUGES Ä

Perform cluster Self Diagnostic Test to determine
whether problem is within cluster or outside of clus-
ter. Refer to Fig. 24 and 25.
Successful completion of the SELF DIAGNOSTIC
TEST indicates that the problem is in the wiring,
connectors or sensors out side of the cluster.
CLUSTER ASSEMBLY REMOVAL
The electronic cluster which is serviced as an as-
sembly is removed with the same procedure as the
conventional cluster.
CONDITION: CLUSTER DISPLAYS DO NOT ILLUMINATE AFTER VEHICLE IS STARTED
(1) Check fuses and verify battery and ignition
voltage at cluster connector. (2) Check ground from cluster connector to instru-
ment panel ground stud.
SWITCH AND PANEL COMPONENT SERVICE
HEADLAMP SWITCH
The headlamp switch is located on the left side of
the switch pod. The switch controls the headlamps,
parking lamps, fog lamps and instrument light dim- ming. If any of the switches require replacement the
entire headlamp switch assembly must be replaced
(Fig. 26 and 27).
REMOVAL
(1) Remove switch pod assembly from the instru-
ment panel. DO NOT attempt to remove instrument
cluster dimmer switch or wiper delay switch knob,
they are not removable. (2) Remove turn signal switch lever by pulling
straight out of switch pod. (3) Remove screws from bottom of switch pod.
(4) Separate inner and outer switch pod halves and
remove turn signal switch to gain access to screw. (5) Remove five inner switch pod panel screws and
3 screws from underneath the switch pod. Separate
the inner bezel from the outer bezel. (6) Remove switch mounting screws before discon-
necting linkage. (7) Disconnect switch linkage from buttons. Pull
the linkage straight up from the switch/button to dis-
engage it and remove switch.
Fig. 23 Mechanical Cluster Lamp Location
Ä INSTRUMENT PANEL AND GAUGES 8E - 51