lock CHEVROLET DYNASTY 1993 Service Manual

2.2L TBI, 2.5L TBI, 2.5L MPI AND 3.0L IGNITION SYSTEMSÐDIAGNOSTIC PROCEDURES
INDEX
page page
Coolant Temperature Sensor Test ............ 13
Failure to Start TestÐ2.5L TBI and 3.0L Engines . 12
General Information ....................... 11
Ignition Coil ............................. 11 Manifold Absolute Pressure (MAP) Sensor Test . 13
Poor Performance Test .................... 13
Spark Plugs ............................ 11
Testing for Spark at Coil ................... 11
GENERAL INFORMATION
For additional information, refer to On Board Di-
agnostics in the Fuel Injection General Diagnosis
sections of Group 14. Also, refer to the DRBII scan
tool and appropriate Powertrain Diagnostic Proce-
dures Manual.
SPARK PLUGS
Faulty or fouled spark plugs may perform well at
idle speed, but frequently fail at higher engine
speeds. Faulty plugs can be identified in a number of
ways: poor fuel economy, power loss, decrease in en-
gine speed, hard starting and, in general, poor en-
gine performance. Spark plugs also malfunction because of carbon
fouling, excessive electrode air gap, or a broken insu-
lator. Refer to the General Information Section of
this group for spark plug diagnosis.
IGNITION COIL
The ignition coil is designed to operate without an
external ballast resistor. Inspect the coil for arcing. Test the coil according
to coil tester manufacturer's instructions. Test coil
primary and secondary resistance. Replace any coil
that does not meet specifications. Refer to the Coil
Resistance chart. If the ignition coil is replaced due to a burned
tower, carbon tracking, arcing at the tower, or dam-
age to the terminal or boot on the coil end of the sec-
ondary cable, the cable must be replaced. Arcing at the tower will carbonize the nipple which, if it is con-
nected to a new coil, will cause the coil to fail. If a secondary cable shows any signs of damage,
the cable should be replaced with a new cable and
new terminal. Carbon tracking on the old cable can
cause arcing and the failure of a new coil.
TESTING FOR SPARK AT COIL
WARNING: APPLY PARKING BRAKE AND/OR
BLOCK THE WHEELS BEFORE PERFORMING ANY
TEST WITH THE ENGINE RUNNING.
CAUTION: Spark plug cables may be damaged if
this test is performed with more than 1/4 inch clear-
ance between the cable and engine ground.
Remove the coil secondary cable from the distribu-
tor cap. Hold the end of cable about 6 mm (1/4-inch)
away from a good engine ground (Fig. 1). Crank the
engine and inspect for spark at the coil secondary ca-
ble. There must be a constant spark at the coil second-
ary cable. If the spark is constant, have a helper con-
tinue to crank engine and, while slowly moving coil
secondary cable away from ground, look for arcing at
the coil tower. If arcing occurs at the tower, replace
the coil. If spark is not constant or there is no spark,
proceed to the failure to start test. If a constant spark is present and no arcing occurs
at the coil tower, the ignition system is producing
the necessary high secondary voltage. However,
COIL RESISTANCE
Ä IGNITION SYSTEMS 8D - 11

make sure that the spark plugs are firing. Inspect the
distributor rotor, cap, spark plug cables, and spark
plugs. If they are in proper working order, the ignition
system is not the reason why the engine will not start.
Inspect the fuel system and engine for proper opera-
tion.
FAILURE TO START TESTÐ2.5L TBI AND 3.0L
ENGINES
Before proceeding with this test make sure
Testing For Spark At Coil has been performed.
Failure to do this may lead to unnecessary diag-
nostic time and wrong test results.
WARNING: BE SURE TO APPLY PARKING BRAKE
AND/OR BLOCK WHEELS BEFORE PERFORMING
ANY TEST WITH THE ENGINE RUNNING.
(1) Battery voltage must be at least 12.4 volts to
perform test. (2) Crank the engine for 5 seconds while monitoring
the voltage at the coil positive (+) terminal (Fig. 2 or
Fig. 3). If the voltage remains near zero during the
entire period of cranking, refer to Group 14 for On-
Board Diagnostic checks. Also, refer to the DRBII scan
tool and the appropriate Powertrain Diagnostic Proce-
dures manual. These checks will help diagnose prob-
lems with the PCM and auto shutdown relay. (3) If voltage is at near-battery voltage and drops to
zero after 1-2 seconds of cranking, refer to On-Board
Diagnostic in Group 14. Also, refer to the DRBII scan
tool and the appropriate Powertrain Diagnostic Proce-
dures manual. These tests will help check the distribu-
tor reference pickup circuit to the PCM. (4) If voltage remains at near battery voltage during
the entire 5 seconds, with the key off,remove the
PCM 60-way connector. Check the 60-way connector
for any terminals that are pushed out or loose. (5) Remove the connector to coil (+) and connect a
jumper wire between battery (+) and coil (+). (6) Using the special jumper (Fig. 4), momentarily ground terminal #19 of the 60-way connector (Fig.
5). A spark should be generated when the ground is
removed.
(7) If spark is generated, replace the PCM.
(8) If no spark is seen, use the special jumper to
ground the coil (-) terminal directly. (9) If spark is produced, inspect wiring harness for
an open condition.
Fig. 2 Coil TerminalsÐ2.2L TBI, 2.5L TBI and 2.5L MPI Engines
Fig. 3 Coil TerminalsÐ3.0L Engine
Fig. 4 Special Jumper to Ground Coil Negative
Fig. 1 Checking for Spark
8D - 12 IGNITION SYSTEMS Ä

(10) If no spark is produced, replace the ignition coil.
POOR PERFORMANCE TEST
To prevent unnecessary diagnostic time and
possible incorrect results, the Testing For Spark
At Coil procedure should be performed before
this test.
WARNING: APPLY PARKING BRAKE AND/OR BLOCK
THE WHEELS BEFORE PERFORMING ANY ENGINE
RUNNING TESTS.
Check and adjust basic timing (refer to the specifica-
tion section of this group and see service procedures).
COOLANT TEMPERATURE SENSOR TEST
(1) With key off, disconnect wire connector from
coolant temperature sensor (Fig. 6). (2) Connect one lead of ohmmeter to one terminal of
coolant temperature sensor. (3) Connect the other lead of ohmmeter to remaining
terminal of coolant temperature sensor. The ohmmeter
should read as follows;
² Engine/Sensor at normal operating temperature
around 200ÉF should read approximately 700 to 1,000
ohms.
² Engine/Sensor at room temperature around 70ÉF,
ohmmeter should read approximately 7,000 to 13,000
ohms. Refer to On Board Diagnostics in the General
Diagnosis section of Group 14. Also, refer to the
DRBII scan tool and the appropriate Powertrain
Diagnostic Procedures manual for additional
test procedures.
MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR
TEST
Refer to the DRB II scan tool and appropriate Pow-
ertrain Diagnostic Procedures manual for further test
procedures.
Fig. 5 60-Way Electrical Connector, Powertrain con- trol module
Fig. 6 Coolant Temperature Sensor Test
Ä IGNITION SYSTEMS 8D - 13

(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

Fig. 10). Turn distributor housing to adjust timing.
Tighten the hold-down arm screw and recheck timing.
(8) Turn the engine off. Remove timing light or
magnetic timing unit and tachometer. If the coolant
temperature sensor was disconnected, connect the sen-
sor and erase fault codes using the Erase Fault
Code Mode on the DRBII scan tool.
DISTRIBUTORÐ2.2L TBI, 2.5L TBI AND 2.5L MPI
ENGINES
REMOVAL
(1) Disconnect distributor pick-up connector from
wiring harness connector (Fig. 11).
(2) Remove splash shield retaining screws (Fig.
12). (3) Remove splash shield (Fig. 12).
(4) Loosen distributor cap retaining screws (Fig.
13). (5) Lift cap off of distributor (Fig. 14).
(6) Rotate engine crankshaft until the distributor
rotor is pointing toward the cylinder block. Use this
as reference when reinstalling distributor. (7) Remove distributor hold-down screw.
(8) Carefully lift the distributor from the engine.
Fig. 10 Distributor HolddownÐ3.0L Engine
Fig. 11 Distributor Pickup ConnectorÐ2.5L Engine
Fig. 7 Timing ScaleÐ2.2L TBI, 2.5L TBI and 2.5L MPI Engines
Fig. 8 Timing ScaleÐ3.0L Engine
Fig. 9 Distributor HolddownÐ2.5L Engine
Ä IGNITION SYSTEMS 8D - 17

INSTALLATION
(1) Position distributor in engine. Make certain that
the O-ring is properly seated on distributor. If O-ring is
cracked or nicked, replace it with new one. (2) Carefully engage distributor drive with auxiliary
shaft drive. When distributor is installed properly,
rotor will be pointing toward cylinder block. If engine
has been cranked while distributor is removed,
establish proper relationship between the dis-
tributor shaft and Number 1 piston position as
follows: (a) Rotate the crankshaft until number one piston
is at top of compression stroke. Pointer on clutch
housing should be in line with the O(TDC)mark on
flywheel. (b) Rotate rotor to a position just ahead of the
number one distributor cap terminal. (c) Lower the distributor into the opening, engag-
ing distributor drive with drive on auxiliary shaft. With distributor fully seated on engine, rotor should
be under the cap number 1 tower.
(3) Install the distributor cap. Ensure all high ten-
sion wires snap firmly in the cap towers. (4) Install hold-down arm screw and finger tighten.
(5) Install splash shield.
(6) Connect distributor pick-up connector lead wire
at wiring harness connector. (7) Set ignition timing to specification. Refer to Ig-
nition Timing.
DISTRIBUTOR PICK-UPÐ2.2L TBI, 2.5L TBI AND
2.5L MPI ENGINES
REMOVAL
(1) Remove splash shield and cap. Refer to Distribu-
tor Removal. (2) Remove rotor from shaft (Fig. 15).
(3) Remove Hall effect pick-up assembly (Fig.
16).
INSTALLATION
(1) Place pick-up assembly into distributor housing
(Fig. 16). The distributor pick-up wires may be damaged
if not properly reinstalled. (2) Install rotor (Fig. 15).
(3) Install cap and splash shield. Refer to Distribu-
tor Installation.
DISTRIBUTOR SERVICEÐ3.0L ENGINE
REMOVAL
(1) Disconnect distributor connector from wiring
harness connector (Fig. 17).
Fig. 12 Splash ShieldÐ2.5L Engine
Fig. 13 Distributor Cap Retaining ScrewsÐ2.5L En- gine
Fig. 14 Distributor CapÐ2.5L Engine
8D - 18 IGNITION SYSTEMS Ä

(2) With engine running, move test probe along
entire length of all cables (approximately 0 to 1/8
inch gap). If punctures or cracks are present there
will be a noticeable spark jump from the faulty area
to the probe. Cracked, leaking or faulty cables should
be replaced. Use the following procedure when removing the
high tension cable from the spark plug. First, remove
the cable from the retaining bracket. Then grasp the
terminal as close as possible to the spark plug. Ro-
tate the cover (boot) slightly and pull straight back.
Do not use pliers and do not pull the cable at an
angle. Doing so will damage the insulation, cable
terminal or the spark plug insulator. Wipe spark
plug insulator clean before reinstalling cable
and cover. Resistance cables are identified by the words Elec-
tronic Suppression .
Use an ohmmeter to check cables for opens, loose
terminals or high resistance. (a) Remove cable from spark plug.
(b) Remove cable from the coil tower.
(c) Connect the ohmmeter between spark plug
end terminal and the coil end terminal. Resistance
should be within tolerance shown in the cable re-
sistance chart. If resistance is not within tolerance,
replace cable assembly. Test all spark plug cables
in same manner.
SPARK PLUG SERVICE
When replacing the spark plug cables, route the ca-
bles correctly and secure them in the appropriate re-
tainers. Incorrectly routed cables can cause the radio
to reproduce ignition noise. It can also cause cross ig-
nition of the spark plugs or short circuit the cables to
ground.
SPARK PLUG REMOVAL
Always remove cables by grasping at boot, rotating
the boot 1/2 turn, and pulling straight back in a
steady motion. (1) Prior to removing the spark plug spray com-
pressed air around the spark plug hole and the area
around the spark plug. (2) Remove the spark plug using a quality socket
with a rubber or foam insert. (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) To avoid cross threading, start the spark plug
into the cylinder head by hand. (2) Tighten spark plugs to 28 N Im (20 ft. lbs.)
torque. (3) Install spark plug cables over spark plugs.
IDLE RPM TEST
WARNING: BE SURE TO APPLY PARKING BRAKE
AND/OR BLOCK WHEELS BEFORE PERFORMING
ANY ENGINE RUNNING TESTS.
Engine idle set rpmshould be tested and recorded
as it is when the vehicle is first brought into shop
for testing. This will assist in diagnosing complaints
of engine stalling, creeping and hard shifting on ve-
hicles equipped with automatic transaxle. Refer to the
Throttle Body Minimum Airflow procedures in Group
14.
IGNITION TIMING PROCEDURE
Ignition timing cannot be changed or set on Turbo
III, 3.3L or 3.8L engines. For diagnostic information,
refer to the DRBII scan tool and the appropriate
Powertrain Diagnostics Procedures manual.
CABLE RESISTANCE CHART
Fig. 6 Setting Spark Plug GapÐTypical
Ä IGNITION SYSTEMS 8D - 41

IGNITION SWITCH
IGNITION SWITCH AND KEY CYLINDER SERVICE
The ignition switch is located on the steering col-
umn. The Key In Switch is located in the ignition
switch module. For diagnosis of the Key In Switch,
refer to Section 8M.
REMOVAL
If the vehicle has a floor mounted gear shifter,
place the selector in the Park position. (1) Disconnect negative cable from battery.
(2) If the vehicle has a tilt column, remove the tilt
lever by turning it counterclockwise. (3) Remove upper and lower covers from steering
column.
(4) Remove ignition switch mounting screws. Use
tamper proof torx bit Snap-on TTXR15A2, TTXR20A2
or equivalent to remove the screws (Fig. 1). (5) Gently pull switch away from the column. Release
connector locks on the 7 terminal wiring connector,
then remove the connector from the ignition switch.
(6) Release connector lock on the 4 terminal con-
nector, then remove the connector from the ignition
switch. (7) To remove the key cylinder from the ignition
switch: (a) Insert key in the ignition switch. Turn the
key to the LOCK position. Using a small screw-
driver, depress the key cylinder retaining pin until
it is flush with the key cylinder surface (Fig. 2). (b) Rotate the key clockwise to the OFF position.
The key cylinder will unseat from the ignition
switch (Fig. 3). When the key cylinder is unseated,
it will be approximately 1/8 inch away from the ig-
nition switch halo light ring. Do not attempt to
remove the key cylinder at this time. (c) With the key cylinder in the unseated posi-
tion, rotate the key counterclockwise to the lock po-
sition and remove the key. (d) Remove key cylinder from ignition switch
(Fig. 4).
INSTALLATION
If the vehicle has a floor mounted gear shifter,
place the selector in the Park position.
IGNITION SWITCH DESIGNATIONS
Fig. 1 Ignition Switch Screw Removal
Fig. 2 Key Cylinder Retaining Pin
Ä IGNITION SYSTEMS 8D - 45

(1) Connect electrical connectors to the ignition
switch. Make sure that the switch locking tabs are fully
seated in the wiring connectors. (2) Before attaching the ignition switch to a tilt
steering column, the transaxle shifter must be in the
Park position. Also the park lock dowel pin and the
column lock flag must be properly indexed before
installing the switch (Fig. 5). (a) Place the transaxle shifter in the PARK posi-
tion. (b) Place the ignition switch in the lock position.
The switch is in the lock position when the column
lock flag is parallel to the ignition switch terminals
(Fig. 5). (c) Position ignition switch park lock dowel pin so
it will engage the steering column park lock slider
linkage (Fig. 6). (d) Apply a light coating of grease to the column
lock flag and the park lock dowel pin.
(3) Place the ignition switch against the lock hous-
ing opening on the steering column. Ensure ignition
switch park lock dowel pin enters the slot in the park
lock slider linkage in the steering column. (4) Install ignition switch mounting screws. Tighten
screws to 2 N Im (17 in. lbs.) torque.
(5) Install steering column covers. Tighten screws to
2N Im (17 in. lbs.) torque.
(6) If the vehicle is equipped with a tilt steering
column, install the tilt lever. (7) To install the ignition key in the lock cylinder:(a) With the key cylinder and the ignition switch
in the Lock position, insert the key cylinder into the
ignition switch until it bottoms. (b) Insert ignition key into lock cylinder. While
gently pushing the key cylinder in toward the igni-
tion switch, rotate the ignition key until to the end of
travel. (c) Connect negative cable to battery.
(8) Check for proper operation of the halo light, shift
lock (if applicable), and column lock. Also check for
proper operation of the ignition switch accessory, lock,
off, run, and start positions.
Fig. 3 Unseated Key Cylinder
Fig. 4 Key Cylinder Removal
Fig. 5 Ignition Switch View From Column
Fig. 6 Ignition Switch Mounting Pad
8D - 46 IGNITION SYSTEMS Ä

INSTRUMENT PANEL AND GAUGES
CONTENTS
page page
AA BODY .............................. 1
AC AND AY BODIES .................... 23 AG AND AJ BODIES
.................... 42
AP BODY ............................. 58
AA BODY INDEX
page page
Cluster and Gauge Service and Testing ........ 2
Electronic Cluster ........................ 13
Fuel GaugeÐFlexible Fuel .................. 2
Gauges ................................. 7
General Information ........................ 1 Instrument Panel
......................... 21
Interior Lamp Replacement ................. 21
Mechanical/Electronic Cluster Removal ......... 5
Switch and Panel Component Service ......... 15
GENERAL INFORMATION
INSTRUMENT CLUSTERS
There are three instrument cluster assemblies. The
mechanical clusters incorporate magnetic type
gauges. The electronic instrument cluster incorpo-
rates, a digital speedometer/odometer and electronic
analog gauges. The mechanical Lo-Line instrument cluster has
magnetic type gauges for coolant temperature, fuel
level and charging system voltage (Fig. 1).
The mechanical Hi-Line instrument cluster has
magnetic type gauges for oil pressure, coolant tem-
perature, charging system voltage and fuel level. The
premium instrument cluster also has a tachometer
(Fig. 2). If the ignition switch is in the OFF position each
gauge will show a reading, except for the volt gauge. However the readings are only accurate when the ig-
nition 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.
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.
MESSAGE CENTER
The message center includes the graphic display of
the car with illuminating graphics for: low wind-
Fig. 1 Instrument Cluster
Fig. 2 Instrument Cluster With Tachometer
Ä INSTRUMENT PANEL AND GAUGES 8E - 1