1993 CHEVROLET PLYMOUTH ACCLAIM Index

3.3L AND 3.8L MULTI-PORT FUEL INJECTIONÐGENERAL DIAGNOSIS INDEX
page page
Fuel System Diagram .................... 157 Visual Inspection........................ 157
FUEL SYSTEM DIAGRAM
Refer to the Component Identification portion of
this section for a more complete description of the
components shown in Fig. 1.
VISUAL INSPECTION
Perform a visual inspection for loose, disconnected,
or misrouted wires and hoses before diagnosing or
servicing the fuel injection system. A visual check
saves unnecessary test and diagnostic time. A thor-
ough visual inspection includes the following checks: (1) Check ignition cable routing from the coil pack
to the spark plugs. Verify the cable are routed in the
correct order and are fully seated to the coil and
spark plug. (2) Check direct ignition system (DIS) coil electri-
cal connection for damage and a complete connection
to the coil (Fig. 2). (3) Verify the camshaft position sensor electrical
connector is connected to the harness and not dam-
aged (Fig. 3). (4) Ensure the engine temperature sensor electri-
cal connector is connected to the sensor and not dam-
aged (Fig. 3). (5) Ensure the coolant temperature sensor electri-
cal connector is connected to the sensor and not dam-
aged (Fig. 4). (6) Verify the quick connect fuel fittings are fully
inserted on the fuel supply and return tubes. (7) Check the vacuum hose connection at the fuel
pressure regulator for damage or leakage (Fig. 5). (8) Check the oil pressure sending unit electrical
connection (Fig. 6). (9) Verify the electrical connector is attached to
the Purge Solenoid (Fig. 7) and not damaged. (10) Verify the vacuum connection at the purge so-
lenoid is secure and not leaking (Fig. 7).
Fig. 1 Multi-Port Fuel Injection Components
Ä FUEL SYSTEMS 14 - 157

3.3L AND 3.8L MULTI-PORT FUEL INJECTIONÐON-BOARD DIAGNOSTICS INDEX
page page
60-Way Pcm Wiring Connector ............. 167
Circuit Actuation Test Mode ................ 166
Diagnostic Trouble Code Description ......... 163
General Information ...................... 162
High and Low Limits ..................... 163
Monitored Circuits ....................... 162 Non-Monitored Circuits
................... 162
State Display Test Mode .................. 163
System Tests .......................... 163
Throttle Body Minimum Air Flow Check Procedure ............................ 166
GENERAL INFORMATION
The powertrain control module (PCM) has been
programmed to monitor many different circuits of the
fuel injection system. If a problem is sensed with a
monitored circuit often enough to indicate an actual
problem, the PCM stores a fault. If the problem is re-
paired or ceases to exist, the PCM cancels the Diag-
nostic trouble code after 51 vehicle key on/off cycles. Certain criteria must be met for a diagnostic trou-
ble code to be entered into the PCM memory. The
criteria may be a specific range of engine RPM, en-
gine temperature, and/or input voltage to the PCM. It is possible a diagnostic trouble code for a moni-
tored circuit may not be entered into memory even
though a malfunction has occurred. This may happen
because one of the diagnostic trouble code criteria for
the circuit has not been met. For example, assume
one of the diagnostic trouble code criteria for a sen-
sor circuit is the engine must be operating between
750 and 2000 RPM. If the sensor output circuit
shorts to ground when engine RPM is above 2400
RPM (resulting i n a 0 volt input to the PCM) a diag-
nostic trouble code will not be entered into memory.
This is because the condition does not occur within
the specified RPM range. There are several operating conditions that the
PCM does not monitor and set diagnostic trouble
codes for. Refer to Monitored Circuits and Non-Mon-
itored Circuits in this section. Stored diagnostic trouble codes can be displayed ei-
ther by cycling the ignition key On - Off - On - Off -
On, or through use of the DRBII scan tool. The
DRBII scan tool connects to the data link connector
in the vehicle (Fig. 1).
MONITORED CIRCUITS
The powertrain control module (PCM) can detect
certain fault conditions in the fuel injection system. Open or Shorted Circuit - The PCM can deter-
mine if the sensor output (input to PCM) is within
proper range. Also, the PCM can determine if the cir-
cuit is open or shorted. Output Device Current Flow - The PCM senses whether the output devices are hooked up. If there is
a problem with the circuit, the PCM senses whether
the circuit is open, shorted to ground, or shorted
high. Oxygen Sensor - The PCM can determine if the
oxygen sensor is switching between rich and lean
once the system has entered closed loop. Refer to
Modes of Operation in this section for an explanation
of closed loop operation.
NON-MONITORED CIRCUITS
The powertrain control module (PCM) does not
monitor the following circuits, systems and condi-
tions that could have malfunctions that result in
driveability problems. Diagnostic trouble codes may
not be displayed for these conditions. However, prob-
lems with these systems may cause diagnostic trou-
ble codes to be displayed for other systems. For
example, a fuel pressure problem will not register a
fault directly, but could cause a rich or lean condi-
tion. This could cause an oxygen sensor fault to be
stored in the PCM. Fuel Pressure - Fuel pressure is controlled by the
vacuum assisted fuel pressure regulator. The PCM
cannot detect a clogged fuel pump inlet filter, clogged
in-line fuel filter, or a pinched fuel supply or return
Fig. 1 Powertrain Control Module (PCM)
14 - 162 FUEL SYSTEMS Ä

line. However, these could result in a rich or lean
condition causing an oxygen sensor fault to be stored in
the PCM. Secondary Ignition Circuit - The PCM cannot
detect an inoperative ignition coil, fouled or worn spark
plugs, ignition cross firing, or open spark plug cables. Engine Timing - The PCM cannot detect an incor-
rectly indexed timing chain, camshaft sprocket and
crankshaft sprocket. However, these could result in a
rich or lean condition causing an oxygen sensor fault to
be stored in the PCM. Cylinder Compression - The PCM cannot detect
uneven, low, or high engine cylinder compression. Exhaust System - The PCM cannot detect a
plugged, restricted or leaking exhaust system. Fuel Injector Malfunctions - The PCM cannot
determine if a fuel injector is clogged, the needle is
sticking or the wrong injector is installed. However,
these could result in a rich or lean condition causing an
oxygen sensor fault to be stored in the PCM. Excessive Oil Consumption - Although the PCM
monitors exhaust stream oxygen content when the
system is in closed loop, it cannot determine excessive
oil consumption. Throttle Body Air Flow - The PCM cannot detect a
clogged or restricted air cleaner inlet or filter element. Evaporative System - The PCM will not detect a
restricted, plugged or loaded evaporative purge canis-
ter. Vacuum Assist - Leaks or restrictions in the
vacuum circuits of vacuum assisted engine control
system devices are not monitored by the PCM. How-
ever, these could result in a MAP sensor fault being
stored in the PCM. PCM System Ground - The PCM cannot determine
a poor system ground. However, a diagnostic trouble
code may be generated as a result of this condition. PCM Connector Engagement - The PCM cannot
determine spread or damaged connector pins. How-
ever, a diagnostic trouble code may be generated as a
result of this condition.
HIGH AND LOW LIMITS
The powertrain control module (PCM) compares in-
put signal voltages from each input device with estab-
lished high and low limits for the device. If the input
voltage is not within limits and other diagnostic
trouble code criteria are met, a diagnostic trouble code
will be stored in memory. Other diagnostic trouble code
criteria might include engine RPM limits or input
voltages from other sensors or switches that must be
present before a fault condition can be verified.
DIAGNOSTIC TROUBLE CODE DESCRIPTION
A diagnostic trouble code indicates that the power-
train control module (PCM) has recognized an abnor- mal condition in the system. Diagnostic trouble codes
can be obtained from the malfunction indicator lamp
(Check Engine lamp on the instrument panel) or from
the DRBII scan tool. Diagnostic trouble codes indicate
the results of a failure but do not identify the failed
component directly.
SYSTEM TESTS
WARNING: APPLY PARKING BRAKE AND/OR BLOCK
WHEELS BEFORE PERFORMING ANY TEST ON AN
OPERATING ENGINE.
OBTAINING DIAGNOSTIC TROUBLE CODES
(1) Connect the DRBII scan tool to the data link
connector located in the engine compartment near the
driver side strut tower (Fig. 1). (2) Start the engine if possible, cycle the transaxle
selector and the A/Cswitch if applicable. Shut off the
engine. (3) Turn the ignition switch on, access Read Fault
Screen. Record all the fault messages shown on the
DRBII scan tool. Observe the malfunction indicator
lamp (check engine lamp on the instrument panel). The
lamp should light for 2 seconds then go out (bulb
check). Diagnostic trouble code erasure; access erase
diagnostic trouble code data
STATE DISPLAY TEST MODE
The switch inputs used by the powertrain control
module (PCM) have only two recognized states, HIGH
and LOW. For this reason, the PCM cannot recognize
the difference between a selected switch position ver-
sus an open circuit, a short circuit, or a defective
switch. If the change is displayed, it can be assumed
that the entire switch circuit to the PCM is functional.
From the state display screen access either State
Display Inputs and Outputs or State Display Sensors.
STATE DISPLAY INPUTS AND OUTPUTS
Connect the DRBII scan tool to the vehicle and access
the State Display screen. Then access Inputs and
Outputs. The following is a list of the engine control
system functions accessible through the Inputs and
Outputs screen. Park/Neutral Switch
Speed Control Resume
Brake Switch
Speed Control On/Off
Speed Control Set
A/C Switch Sense
S/C Vent Solenoid
Ä FUEL SYSTEMS 14 - 163

3.3L AND 3.8L MULTI-PORT FUEL INJECTIONÐSERVICE PROCEDURES INDEX
page page
Camshaft Position Sensor Service ........... 176
Crankshaft Position Sensor ................ 176
EVAP Canister Purge Solenoid Service ....... 175
Fuel Injector ........................... 174
Fuel Injector Rail Assembly ................ 170
Fuel Pressure Regulator .................. 173
Fuel System Pressure Release Procedure ..... 169 Heated Oxygen Sensor (O
2Sensor) Service . . . 177
Idle Air Control Motor .................... 170
Manifold Absolute Pressure (MAP) Sensor ..... 175
PCM Service ........................... 175
Throttle Body ........................... 169
Throttle Body Removal ................... 169
Throttle Position Sensor .................. 169
THROTTLE BODY REMOVAL
(1) Disconnect negative battery cable.
(2) Remove the air cleaner to throttle body hose
clamp. Remove the nut holding the air cleaner as-
sembly to the air cleaner bracket. Remove the air
cleaner (Fig. 1). (3) Remove throttle and the speed control cables.
(4) Disconnect electrical connectors from the idle
air control motor and throttle position sensor (TPS). (5) Disconnect vacuum hoses from throttle body.
(6) Remove throttle body to intake manifold at-
taching nuts. (7) Remove throttle body and gasket.
(8) Reverse the above procedure for installation.
THROTTLE BODY
When servicing throttle body components, always
reassemble components with new O-rings and seals
where applicable (Fig. 2). Never use lubricants on
O-rings or seals, damage may result. If assembly of component is difficult, use water to aid assembly.
Use care when removing hoses to prevent damage to
hose or hose nipple.
FUEL SYSTEM PRESSURE RELEASE PROCEDURE
WARNING: THE 3.3L AND 3.8L MPI FUEL SYSTEMS
ARE UNDER A CONSTANT PRESSURE OF AP-
PROXIMATELY 330 KPA (48 PSI). RELEASE FUEL
SYSTEM PRESSURE BEFORE SERVICING THE
FUEL PUMP, FUEL LINES, FUEL FILTER, THROT-
TLE BODY OR FUEL INJECTORS.
(1) Disconnect negative cable from battery.
(2) Remove fuel filler cap.
(3) Remove the protective cap from the fuel pres-
sure test port on the fuel rail (Fig. 3). (4) Place the open end of fuel pressure release
hose, tool number C-4799-1, into an approved gaso-
line container. Connect the other end of hose
C-4799-1 to the fuel pressure test port. Fuel pressure
will bleed off through the hose into the gasoline con-
tainer. Fuel gauge C-4799-A contains hose C-4799-1. (5) Continue fuel system service.
THROTTLE POSITION SENSOR
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove electrical connector from throttle posi-
tion sensor. (3) Remove throttle position sensor mounting
screws (Fig. 4). (4) Lift throttle position sensor off throttle shaft.
INSTALLATION
(1) Install throttle position sensor on throttle shaft.
Install mounting screws. Tighten screw to 2 N Im (17
in. lbs.) torque. (2) Connect electrical connector to throttle position
sensor. (3) Connect negative cable to battery.Fig. 1 Throttle Body Assembly
Ä FUEL SYSTEMS 14 - 169

STEERING
CONTENTS
page page
ACUSTAR STANDARD AND TILT STEERING COLUMN ............................ 28
AUTOMATIC TRANSMISSION SHIFTER/IGNITION INTERLOCK .......................... 36
GENERAL INFORMATION .................. 1 POWER STEERING GEAR
................ 25
POWER STEERING PUMPS ................ 1
SPECIFICATIONS AND TIGHTENING REFERENCE .......................... 42
GENERAL INFORMATION
Safety goggles should be worn at all times
when working on any steering gear or pump. Throughout this group, references may be made to
a particular vehicle by letter or number designation.
A chart showing the breakdown of these designations
is included in the Introduction Section at the front of
this service manual. The power steering system consists of these four
major components. Power Steering Pump, Power
Steering Gear, Pressure Hose, and Return Line.
Turning of the steering wheel is converted into lin-
ear travel through the meshing of the helical pinion teeth with the rack teeth. Power assist steering is
provided by an open center, rotary type control valve.
It is used to direct oil from the power steering pump
to either side of the integral steering rack piston. Road feel is controlled by the diameter of a torsion
bar which initially steers the vehicle. As steering ef-
fort increases as in a turn, the torsion bar twists,
causing relative rotary motion between the rotary
valve body and valve spool. This movement directs
oil behind the integral rack piston, which in turn,
builds up hydraulic pressure and assists in the turn-
ing effort.
POWER STEERING PUMPS
INDEX
page page
Checking Power Steering Fluid Level .......... 9
Flow Control Valve Fitting O-Ring Seal ........ 23
General Information ........................ 1
Power Steering Hoses ..................... 11
Power Steering Pressure Switch ............. 10
Power Steering Pump Fluid Reservoirs ........ 22 Power Steering Pump Pressure Test
........... 9
Power Steering Pump Pulley Service .......... 20
Power Steering Pump Removal .............. 12
Power Steering Pump Service ................ 2
Power Steering PumpÐInitial Operation ....... 24
Steering Components Service Diagnosis ........ 2
GENERAL INFORMATION
Hydraulic pressure for operation of the power
steering gear is provided by a belt driven power
steering pump. The power steering pump is a con-
stant flow rate and displacement, vane type pump.
Different styles of Saginaw power steering pumps are
used depending on the engine application of the ve-
hicle. On all four cylinder and 3.0-liter V-6 applications
the Saginaw Ham Can power steering pump is used
(Fig. 1). On the 3.3 & 3.8-liter V-6 and Turbo III applica-
tions, different versions of the Saginaw T/C style
power steering pump is used (Fig. 2). The 3.3 & 3.8 liter V-6 engine application uses the T/C style power
steering pump with a remote mounted reservoir for
the power steering fluid. On the Turbo III application
of the T/C style power steering pump, the power
steering fluid reservoir is integral to the power steer-
ing pump. On the integral reservoir type pump (Fig. 1) the
pump housing and internal components are combined
with the reservoir to form a one-piece mechanism. The Saginaw T/C style power steering pump (Fig.
2), consists of the power steering pump internal com-
ponents and pump housing. The Saginaw T/C style
power steering pump though has no internal reser-
voir for the power steering fluid. Depending on vehi-
Ä STEERING 19 - 1

POWER STEERING GEAR INDEX
page page
General Information ....................... 25
Outer Tie Rod ........................... 27 Steering Gear Service
..................... 25
GENERAL INFORMATION
The power steering gear (Fig. 1) should NOT be
serviced or adjusted. If a malfunction or oil leak
occurs. The complete steering gear should be
replaced. If a steering gear boot needs to be replaced due to
damage, refer to the power steering gear service sec-
tion in this manual for proper procedure. The power steering system consists of these four
major components. Power Steering Gear, Power Steer-
ing Pump, Pressure Hose, and Return Line. Turning of
the steering wheel is converted into linear travel
through the meshing of the helical pinion teeth with
the rack teeth. Power assist steering is provided by an
open center, rotary type control valve which directs oil
from the pump to either side of the integral rack piston. Road feel is controlled by the diameter of a torsion
bar which initially steers the vehicle. As required
steering effort increases, as in a turn. The torsion bar
twists, causing relative rotary motion between the
rotary valve body and the valve spool. This movement
directs oil behind the integral rack piston, which, in
turn, builds up hydraulic pressure and assists in the
turning effort. The drive tangs on the pinion of the power steering
pump mate loosely with a stub shaft. This is to permit
manual steering control to be maintained if the drive
belt on the power steering pump should break. How-
ever, under these conditions, steering effort will be
increased.
STEERING GEAR SERVICE
The power steering gear should NOT be ser-
viced or adjusted. If a malfunction or oil leak
occurs. The complete steering gear should be
replaced.
REMOVAL
(1) Raise vehicle See Hoisting, Group 0. Put oil drain
pan under vehicle to catch power steering fluid. (2) Remove front road wheels.
(3) Remove both tie rod ends from steering knuckles,
using Puller Special Tool C-3894-A (Fig. 1). (4) Disconnect engine damper strut from crossmem-
ber (if so equipped). (5) Remove the 3 front suspension crossmember at-
taching bolts and the nut (Fig. 2) from the locating
stud. Lower front suspension crossmember, using
Fig. 1 Power Steering Gear Assembly
Ä STEERING 19 - 25

ACUSTAR STANDARD AND TILT STEERING COLUMN INDEX
page page
General Information ....................... 28
Ignition Switch Service .................... 34 Steering Column Component Service
......... 34
Steering Column Service Procedures .......... 30
GENERAL INFORMATION
WARNING: THE AIR BAG SYSTEM IS A SENSITIVE,
COMPLEX ELECTRO-MECHANICAL UNIT. BEFORE
ATTEMPTING TO DIAGNOSE, REMOVE OR IN-
STALL THE AIR BAG SYSTEM COMPONENTS YOU
MUST FIRST DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE. FAILURE
TO DO SO COULD RESULT IN ACCIDENTAL DE-
PLOYMENT OF THE AIR BAG AND POSSIBLE PER-
SONAL INJURY. THE FASTENERS, SCREWS, AND BOLTS, ORIGI-
NALLY USED FOR THE AIR BAG COMPONENTS,
HAVE SPECIAL COATINGS AND ARE SPECIFI- CALLY DESIGNED FOR THE AIR BAG SYSTEM.
THEY MUST NEVER BE REPLACED WITH ANY
SUBSTITUTES. ANYTIME A NEW FASTENER IS
NEEDED, REPLACE WITH THE CORRECT FASTEN-
ERS PROVIDED IN THE SERVICE PACKAGE OR
FASTENERS LISTED IN THE PARTS BOOKS. BEFORE SERVICING A STEERING COLUMN
EQUIPPED WITH AN AIR BAG, REFER TO GROUP
8M, ELECTRICAL FOR PROPER AND SAFE SER-
VICE PROCEDURES.
Safety goggles should be worn at all times
when working on steering columns.
19 - 28 STEERING Ä

AUTOMATIC TRANSMISSION SHIFTER/IGNITION INTERLOCK INDEX
page page
General Information ....................... 36
Interlock System Adjustment ................ 37 Interlock System Operation Check
............ 36
Shifter/Ignition Interlock Cable ............... 38
GENERAL INFORMATION
The automatic transmission Shifter/Ignition Inter-
lock, is a mechanically cable operated system (Fig.
1). It interconnects the automatic transmission floor
mounted shifter to the steering column ignition
switch. The interlock system locks the floor mounted
shifter on automatic transmission equipped vehicles
into the PARK position. The Interlock system is en-
gaged whenever the ignition switch is in the LOCK
or ACCESSORY position. When the key is in the
OFF or RUN position the shifter is unlocked and will
move into any position. The interlock system also
prevents ignition switch from being turned to the
OFF or ACCESSORY position, unless shifter is fully
locked into the PARK position.
INTERLOCK SYSTEM OPERATION CHECK
(1) With the shifter in PARK, and the shifter knob
pushbutton in its full up position, the ignition switch should rotate freely from OFF to LOCK position.
When the shifter is moved to the DRIVE (or OVER-
DRIVE) position if so equipped the ignition switch
should not rotate from OFF to LOCK. (2) Moving shifter out of PARK should only be pos-
sible when ignition switch is in the OFF or RUN po-
sition. Movement of the shifter from the PARK
position should not be possible, when the ignition
switch is in the LOCK position. (3) If the automatic transmission Shifter/Ignition
Interlock System operates in any way other than as
described above, diagnosis, adjustment or repair of
the system is required. See Adjustment and Repair
procedures in this section of the service manual.
Fig. 1 Shifter Ignition Interlock System Components
19 - 36 STEERING Ä