1993 CHEVROLET DYNASTY odometer

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

AP BODY INDEX
page page
Cluster and Gauge Service and Testing ....... 58
Gauges ................................ 61
General Information ....................... 58 Instrument Panel Replacement
.............. 72
Interior Lamp Replacement ................. 73
Switch and Panel Component Service ......... 67
GENERAL INFORMATION
INSTRUMENT CLUSTER
There are two conventional instrument cluster as-
semblies available. The clusters incorporates mag-
netic type gauges and an electronically driven
speedometer and odometer assembly (Fig. 1 and 2).
MAGNETIC GAUGES
All gauges on the AP Body clusters are the mag-
netic type gauges. When the ignition switch is in the
OFF position each gauge, except for the voltmeter
and tachometer will show a reading. However, 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 the magnetic tachometer in the
high line cluster. This module is located on top of the instrument
cluster.
ELECTRONIC DIGITAL CLOCK
The electronic digital clock is in the radio. The
clock and radio each use the display panel built into
the radio. A digital readout indicates the time in
hours and minutes whenever the ignition switch is in
the ON or ACC position. When the ignition switch is in the OFF position, or
when the radio frequency is being displayed, time
keeping is accurately maintained. The procedure for setting the clock varies slightly
with each radio. The correct procedure is described
under the individual radio operating instructions re-
fer to the Sound Systems Manual supplied with the
vehicle.
WARNING LAMPS AND INDICATOR LIGHTS
The instrument cluster has warning and indicators
lamps for eight different systems:
² Low oil pressure
² Brake warning
² Seat belt warning
² Malfunction indicator (check engine) lamp
² Air Bag
² High beam indicator
² Right and left turn signals.
² Anti-lock (ABS)
CLUSTER AND GAUGE SERVICE AND TESTING
CAUTION: Disconnect the negative battery cable
before servicing the instrument panel. When power
is required for test purposes, reconnect battery ca-
ble for test only. Disconnect the negative battery
cable after test and before continuing service pro-
cedures.
SENDING UNIT TEST
Check for a defective sending unit or wiring, when
a problem occurs with a cluster gauge. Do this before
disassembling the cluster. (1) Sending units and wiring can be checked by
grounding the connector leads, at the sending unit,
in the vehicle. (2) With the ignition in the ON position, a
grounded input will cause the fuel or temperature
gauge to read at or above maximum.
Fig. 1 Instrument Cluster With Tachometer
Fig. 2 Instrument Cluster Without Tachometer
8E - 58 INSTRUMENT PANEL AND GAUGES Ä

ment cluster and pin 43 of the powertrain control
module connector, replace the powertrain control
module. (8) If all tests performed test good replace the ta-
chometer drive module. (9) If the tachometer continues to be inoperative,
replace the tachometer assembly.
TACHOMETER DRIVE MODULE REPLACEMENT
(1) Remove instrument cluster (Fig. 13).
(2) Remove drive module by pivoting upward from
printed circuit board and pulling away from locating
notches. (3) For installation, position module on locating
notches and push down securely over printed circuit
board and reverse above procedures.
SPEEDOMETER SYSTEM
AP-body 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 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. 14 Speedom-
eter Diagnosis.
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.
SPEEDOMETER/ODOMETER ASSEMBLY REPLACEMENT
(1) Remove cluster bezel.
(2) Remove cluster mask and lens.
(3) Remove tachometer. If equipped.
(4) Remove fuel gauge.
(5) Remove three screws attaching speedometer/
odometer assembly to the cluster housing. (6) Pull speedometer rearward to remove from
cluster housing. (7) For installation reverse above procedures.
VEHICLE SPEED SENSOR REPLACEMENT
(1) Remove harness connector from sensor and
make sure weather seal is on harness connector. (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 (Fig. 15 and 16). (4) For installation reverse above procedures and
seat sensor assembly by hand to insure 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. 17).
(3) For installation, reverse above procedures.
Fig. 12 Powertrain Control Module Pin Location
Fig. 13 Tachometer Drive Module
Ä INSTRUMENT PANEL AND GAUGES 8E - 65