1993 CHEVROLET PLYMOUTH ACCLAIM parking brake

(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

(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

SENDING UNIT TEST
When a problem occurs with a cluster gauge, be-
fore disassembling the cluster to check the gauge,
check for a defective sending unit or wiring. (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 oil, fuel or tempera-
ture gauge to read at or above maximum.
LOW OIL PRESSURE/CHECK GAUGES WARNING LAMP TEST
The low oil pressure/check gauges warning lamp
will illuminate when the ignition key is turned to
the ON position without starting the vehicle. In the cluster assembly without tachometer, the
low oil pressure lamp will illuminate if the engine oil
pressure drops below a safe oil pressure level. In the cluster assembly with tachometer, the Check
Gauges warning lamp illuminates when there is a
problem in oil pressure level, high engine tempera-
ture or low voltage. To test the system turn ignition key to the ON po-
sition. If the lamp fails to light, inspect for a broken
or disconnected wire at the oil pressure combination
unit, which is located at the front of the engine (Figs.
5 and 6). If the wire at the connector checks good,
pull connector loose from the switch terminal and
with a jumper wire ground connector to the engine
(Fig. 7). With the ignition key turned to the ON po-
sition check the warning lamp. If lamp still fails to
light, inspect for a burned out lamp or disconnected
socket in the cluster.
COMBINATION OIL UNIT TEST
The combination oil unit has two functions:
(1) The normal closed circuit keeps the oil pressure
warning/check gauges lamp on until there is oil pres-
sure (Fig. 7). (2) The sending unit provides a resistance that
varies with oil pressure. (3) To test the normally closed oil lamp circuit, dis-
connect the locking connector and measure the resis-
tance between the switch terminal and the metal
housing. The ohmmeter should read 0 ohms. Start
the engine. (4) If there is oil pressure, the ohmmeter should
read an open circuit. (5) To test the sending unit, measure the resis-
tance between the sending unit terminal and the
metal housing. The ohmmeter should read open.
Start the engine. (6) The ohmmeter should read between 30 to 55
ohms, depending on engine speed, oil temperature,
and oil viscosity. (7) If the above results are not obtained, replace
the switch.
BRAKE SYSTEM WARNING LAMP TEST
The brake warning lamp illuminates when parking
brake is applied with ignition key turned ON. The
same lamp will also illuminate should one of the two
service brake systems fail when brake pedal is ap-
plied. To test system turn ignition key ON, and ap-
ply parking brake. If lamp fails to light, inspect for a
burned out lamp, disconnected socket, a broken orFig. 5 Combination Oil Unit (2.5L)
Fig. 6 Combination Oil Unit (3.0L)
Fig. 7 Combination Oil Unit Test
Ä INSTRUMENT PANEL AND GAUGES 8E - 3

off, there should be continuity in the system. Start
the engine. With the engine running, the ohmmeter
should show no continuity. If the above results are
not obtained, replace the switch.
BRAKE SYSTEM WARNING LAMP
The brake warning lamp illuminates when parking
brake is applied with ignition key turned ON. The
same lamp will also illuminate should one of the two
service brake systems fail when brake pedal is ap-
plied. To test system turn ignition key ON, and ap-
ply parking brake. If lamp fails to light, inspect for a
burned out lamp, disconnected socket, a broken or
disconnected wire at switch. The lamp also lights
when the ignition switch is turned to START. To test service brake warning system, raise vehicle
on a hoist and open a wheel cylinder bleeder while a
helper depresses brake pedal and observes warning
light. 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 compart-
ment below master cylinder (Fig.6 and 7). CAUTION: If wheel cylinder bleeder was opened
check master cylinder fluid level.
SEAT BELT WARNING LAMP
For testing of this system, refer to Group 8M, Re-
straint System.
MALFUNCTION INDICATOR (CHECK ENGINE) LAMP
For testing of this system, refer to the Powertrain
Diagnostic Test Procedure Manual.
MECHANICAL/ELECTRONIC CLUSTER REMOVAL
CLUSTER BEZELS REMOVAL
(1) Move gear selector to the low position.
(2) Remove five screws attaching upper bezel to in-
strument panel (Fig. 8). (3) Lift cluster bezel over steering wheel.
(4) Remove four screws attaching lower bezel to in-
strument panel. (5) Lift lower cluster bezel from instrument panel.
(6) For installation reverse above procedures.
CLUSTER MASK AND LENS REMOVAL
(1) Remove cluster bezel.
(2) Remove trip reset knob by pulling straight
back. (3) Remove five screws attaching mask and lens to
cluster. (4) For installation reverse above procedures.
Fig. 4 Combination Oil Sending Unit
Fig. 5 Combination Oil Sending Unit Test
Fig. 6 Brake Warning Lamp Switch
Ä INSTRUMENT PANEL AND GAUGES 8E - 25

(3) With the ignition switch ON, an open (discon-
nected sending unit wire) causes the oil, fuel or tem-
perature gauge to read below low, empty or cold
indicators. (4) If steps 2 and 3 check OK, refer to the individ-
ual sending unit test procedures.
FUEL TANK SENDING UNIT TEST
Refer to Group 14, Fuel for test procedure.
CHECK GAUGES WARNING LAMP TESTS
The check gauges warning lamp will illuminated
when the ignition key is turned to the ON position.
The lamp will illuminate if the engine oil pressure
drops below a safe level. The check gauge lamp will
light for high engine temperature or for low voltage. To test the system turn ignition key to the ON po-
sition. If the lamp fails to light, inspect for a broken
or disconnected wire at the oil pressure combination
sending unit, which is located at the front of the en-
gine (Fig. 13). If the wire at the connector checks
good pull connector loose from the switch terminal
and with a jumper wire ground connector to the en-
gine. With the ignition key turned to the ON posi-
tion check the warning lamp. If lamp still fails to
light, inspect for a burned lamp. If lamp still fails to
light, inspect for a burned out lamp or disconnected
socket in the cluster.
To test the switch disconnect the switch electrical
connector. Attach positive lead of an ohmmeter to
the switch terminal for the gray (GY) wire and the
negative lead to an engine ground. With the engine
off, there should be continuity in the system. Start
the engine. With the engine running, the ohmmeter
should show no continuity. If the above results are
not obtained, replace the switch.
COMBINATION OIL SENDING UNIT TEST
The combination oil sending unit has two func-
tions: (1) The normal closed circuit keeps the oil pressure
warning lamp on until there is oil pressure. (2) The sending unit provides a resistance that
varies with oil pressure. To test the normally closed oil lamp circuit, discon-
nect the locking connector and measure the resis-
tance between the switch terminal and the metal
housing. The ohmmeter should read 0 ohms. Start
the engine (Fig. 14).
If there is oil pressure, the ohmmeter should read
an open circuit. To test the sending unit, measure the resistance
between the sending unit terminal and the metal
housing. The ohmmeter should read open. Start the
engine. The ohmmeter should read between 30 to 55 ohms,
depending on engine speed, oil temperature, and oil
viscosity. If the above results are not obtained, replace the
sending unit.
SEAT BELT WARNING SYSTEM
For testing of this system refer to Group 8U,
Chime Warning/Reminder System.
MALFUNCTION INDICATOR (CHECK ENGINE) SYSTEM
For testing this system refer to the Body Diagnos-
tic Procedures booklet.
BRAKE SYSTEM WARNING LAMP TEST
The brake warning lamp illuminates when parking
brake is applied with ignition key turned ON. The
same lamp will also illuminate should one of the two
service brake systems fail when brake pedal is ap-
plied. To test system turn ignition key ON, and ap-
ply parking brake. If lamp fails to light, inspect for a
burned out lamp, disconnected socket, a broken or
disconnected wire at switch. The lamp also lights
when the ignition switch is turned to START. Refer
to Brake System Warning Lamp Diagnosis Chart
(Fig. 15). To test service brake warning system, raise vehicle
on a hoist and open a wheel cylinder bleeder while aFig. 13 Combination Oil Sending Unit
Fig. 14 Combination Oil Sending Unit Test
Ä INSTRUMENT PANEL AND GAUGES 8E - 47

(7) Unscrew lighter receptacle shell from element
and remove. (8) For installation reverse above procedures.
INSTRUMENT PANEL ROLL DOWN PROCEDURE
CAUTION: Disconnect negative battery cable, in en-
gine compartment, before servicing instrument
panel.
(1) Remove instrument panel center bezel (Fig.
31). (2) Remove upper and lower steering column cov-
ers. (3) Remove the left under panel silencer.
(4) Set parking brake.
(5) Remove console side carpet panels (Fig. 32).
(6) Remove console, refer to Group 23, Body.
(7) Remove transmission range clip and cable loop
end from post on gear shifter (Fig. 33 and 34). (8) Remove adjuster from tab on gear shifter
bracket. By pushing in locking knob on adjuster, and
sliding the adjuster off the tab on the gear shifter
bracket. (a) For installation: insert transmission range
cable into adjuster and line up with the end of the
adjuster. (b) The transmission range indicator must be ad-
justed with the gear shifter in low position. (c) Check the gear selector indicator for proper
alignment. (d) Attach transmission range clip to the ad-
juster to secure cable.
(9) Remove two screws and slide Air Bag Diagnos-
tic Module out of right side of instrument panel cen-
ter stack area, then disconnect wiring. (10) Remove screw from instrument panel dimmer
module at left of steering column and lower module.
Fig. 31 Instrument Panel Components
Fig. 32 Center Console
8E - 56 INSTRUMENT PANEL AND GAUGES Ä

FUEL TANK SENDING UNIT TEST
Refer to Group 14, Fuel for test procedures.
LOW OIL PRESSURE WARNING LAMP TEST
The low oil pressure warning lamp will illuminate
when the ignition key is turned to the ON position
without engine running. The lamp also illuminates
should the engine oil pressure drop below a safe oil
pressure level. To test the system turn ignition key to the ON po-
sition. If the lamp fails to light, inspect for a broken
or disconnected wire at the oil pressure combination
unit, located at the front of the engine (Fig. 3). If the
wire at the connector checks good, pull connector
loose from the switch and with a jumper wire ground
connector to the engine. With the ignition key turned
to the ON position check the warning lamp. If lamp
still fails to light, inspect for a burned out lamp or
disconnected socket in the cluster.
COMBINATION OIL SENDING UNIT TEST
The combination oil sending unit has two func-
tions: (1) The normal closed circuit keeps the oil pressure
warning lamp on until there is oil pressure (Fig. 4).
(2) The sending unit provides a resistance that
varies with oil pressure. To test the normally closed oil lamp circuit, discon-
nect the locking connector and measure the resis-
tance between the switch terminal and the metal
housing. The ohmmeter should read continuity. Start
the engine. If there is oil pressure, the ohmmeter should read
an open circuit. To test the sending unit, measure the resistance
between the sending unit terminal and the metal
housing. The ohmmeter should no continuity. Start
the engine. The ohmmeter should read between 30 to 55 ohms,
depending on engine speed, oil temperature and oil
viscosity. If the above results are not obtained, replace the
sending unit.
SEAT BELT WARNING SYSTEM
For testing of this system refer to Group 8M, Re-
straint Systems.
AIR BAG WARNING SYSTEM
For testing of this system refer to Group 8M, Re-
straint Systems.
MALFUNCTION INDICATOR (CHECK ENGINE) SYSTEM
For testing of this system using DRB II, refer to
the Body Powertrain Diagnostic Procedures.
BRAKE SYSTEM WARNING LAMP TEST
The brake warning lamp illuminates when parking
brake is applied with ignition key turned ON. The
same lamp will also illuminate should one of the two
service brake systems fail when brake pedal is ap-
plied. Refer to Brake system warning Lamp Diagno-
sis (Fig. 5). To test system turn ignition key ON and apply
parking brake. If lamp fails to light, inspect for a
burned out lamp, disconnected socket, a broken or
disconnected wire at switch. The lamp also lights
when the ignition switch is turned to start. To test service brake warning system, raise vehicle
on a hoist and open a wheel cylinder bleeder while a
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 compart-
ment below master cylinder (Fig. 6).
CAUTION: If wheel cylinder bleeder was opened
check master cylinder fluid level.
Fig. 3 Combination Oil Sending Unit
Fig. 4 Combination Oil Sending Unit Test
Ä INSTRUMENT PANEL AND GAUGES 8E - 59