1993 CHEVROLET PLYMOUTH ACCLAIM air conditioning

(2) Remove Accessory Drive Belt. Refer to Cooling
System Group 7 for procedure. (3) Remove accessory drive belt idler pulley (Fig.
7).
(4) Remove air conditioning compressor and set
aside (Fig. 8). (5) Remove generator attaching bolts set aside
(Fig. 8). (6) Remove timing belt covers. Refer to procedure
outlined in this section. (7) Remove right engine mount yoke bolt. Remove
the fasteners holding the strut into place. Remove
strut from engine (Fig. 9). (8) Remove accessory drive belt idler pulley
bracket (Fig. 9). (9) Remove timing belt. Refer to procedure out-
lined in this section. (10) Remove 2 bolts holding solid mount compres-
sor into place, Rotate bracket off engine (Fig. 7).
INSTALLATION
(1) Loosely assemble the bracket to engine with #1
and #2 bolts tighten to 3.3 N Im (30 in. lbs.) (Fig. 8).
(2) Install timing belt. Refer to procedure outlined
in this section. Install timing belt covers. Refer to
procedure outlined in this section. (3) Install strut on stud. Tighten nut #3 and bolt
#4, torque to 54 N Im (40 ft. lbs.) (Fig. 9). Loosen #1
and #2 bolts, then torque to 54 N Im (40 ft. lbs.) (Fig.
10).Install yoke bolt and torque to 102 N Im (75 ft.
lbs.). (4) Install accessory drive belt idler pulley and
bracket (Fig. 8). (5) Install accessory drive belt tensioner pulley
(Fig. 7). (6) Install generator (Fig. 8).
(7) Install air conditioning compressor (Fig. 8).
(8) Install accessory drive belt. Refer to Cooling
System Group 7 for procedure. (9) Connect negative battery cable.
Fig. 6 Solid Mount Compressor Bracket 2.2 & 2.5L Engines
Fig. 7 Accessory Drive System
Ä 2.2/2.5L ENGINE 9 - 15

LEFT SIDE MOUNT
(1) Raise vehicle on hoist and remove left front
wheel. (2) Remove inter splash shield.
(3) Support the transmission with a transmission
jack. (4) Remove the insulator thru bolt from the mount.
(5) Remove the transmission mount fasteners and
remove mount. (6) Reverse removal procedure for installation. En-
sure that the slide tube is seated into the rail
bracket guides. Refer to (Fig. 3) for bolt tightening
specifications. (7) Engine mount adjustment, Refer to Engine
Mount Insulator Adjustment of this section.
ENGINE MOUNT RUBBER INSULATORS
Insulator location on (right side) and transmission
bracket (left side) are adjustable to allow right/left
drive train adjustment in relation to drive shaft as-
sembly length. Check and reposition right engine mount insulator
(left engine mount insulator is floating type and will
adjust automatically (Fig. 3). Adjust drive train posi-
tion, if required, for the following conditions:
² Drive shaft distress: See Driveshafts in Suspen-
sion, Group 2.
² Any front end structural damage (after repair).
² Insulator replacement.
ENGINE MOUNT INSULATOR ADJUSTMENT
(1) Remove the load on the engine motor mounts
by carefully supporting the engine and transmission
assembly with a floor jack. (2) Loosen the right engine mount insulator yoke
screw and two turns on yoke nut, then loosen the
front engine mount bracket to front crossmember
screws and nuts. Left engine mount insulator is sleeved over
shaft and long support bolt to provide lateral
movement adjustment with engine weight re-
moved or not. (3) Pry the engine right or left as required to
achieve the proper drive shaft assembly length. See
Drive Shaft in Suspension Group 2 for driveshaft
identification and related assembly length measur-
ing. (4) Tighten right engine mount insulator yoke nut
to 102 N Im (75 ft. lbs.). Then tighten front engine
mount screws and nuts to 54 N Im (40 ft. lbs.) and
center left engine mount insulator. (5) Recheck drive shaft length.
ENGINE ASSEMBLY
REMOVAL
(1) Disconnect battery.
(2) Mark hood position at hinges and remove hood. (3) Drain cooling system. Refer to Cooling System
Group 7 for draining procedure. (4) Disconnect all electrical connections.
(5) Remove coolant hoses from radiator and en-
gine. (6) Remove radiator and fan assembly.
(7) See Fuel System Group 14, For procedures to
release fuel pressure, disconnect fuel lines and accel-
erator cable. (8) Remove air cleaner assembly.
(9) Hoist vehicle and drain engine oil.
(10) Remove air conditioning compressor mounting
bolts and set compressor aside. (11) Disconnect exhaust pipe at manifold.
(12) Remove transmission inspection cover and
mark flex plate to torque converter position. (13) Remove screws holding torque converter to
flex plate and attach C-clamp on bottom of converter
housing to prevent torque converter from coming out. (14) Remove power steering pump mounting bolts
and set pump aside. (15) Remove two lower transmission to block
screws. (16) Remove starter.
(17) Lower vehicles and disconnect vacuum lines
and ground strap. (18) Install transmission holding fixture.
(19) Attach engine lifting hoist and support en-
gine. (20) Remove upper transmission case to block
bolts. (21) See Engine Mounting in (Fig. 2) and separate
mount/insulators as follows: (a) Mark RIGHT insulator on right yoke and en-
gine plate supports. Remove insulator to rails
screws. (b) Remove FRONT engine mount through bolt
and nut.
Fig. 3 Left Insulator Movement
Ä 3.0L ENGINE 9 - 69

ENGINE MOUNT BRACKET REMOVAL
(1) Remove air conditioning compressor to mount-
ing bracket screws and lay compressor aside (Fig. 4). (2) Remove screws attaching air conditioning com-
pressor mounting bracket and adjustable drive belt
tensioner from block and engine mounting bracket.
Remove both assemblies. (3) Remove steering pump/generator belt tensioner
mounting bolt and remove automatic belt tensioner.
(4) Remove two steering pump to engine mounting
bracket screws and one rear support lock nut. (5) Lay power steering pump aside.
(6) Raise vehicle and remove right inner splash
shield (Fig. 8). (7) Remove crankshaft drive pulleys and torsional
damper (Fig. 9). (8) Lower vehicle and place a jack under engine.
Fig. 5 Drive Belt Inspection
Fig. 6 Air Conditioning Belt
Fig. 7 Generator/Power Steering Belt
Fig. 8 Right Inner Splash ShieldÐTypical
Fig. 9 Crankshaft Drive Pulleys
Ä 3.0L ENGINE 9 - 71

(2) Loosen the right engine mount insulator yoke
screw and 2 turns on yoke nut, then loosen the front
engine mount bracket to front crossmember screws and
nuts. Left engine mount insulator is sleeved over
shaft and long support bolt to provide lateral
movement adjustment with engine weight re-
moved or not. (3) Pry the engine right or left as required to achieve
the proper drive shaft assembly length. See Drive
Shaft in Suspension Group 2 for driveshaft identifica-
tion and related assembly length measuring. (4) Tighten right engine mount insulator yoke nut to
102 N Im (75 ft. lbs.). Then tighten front engine mount
screws and nuts to 54 N Im (40 ft. lbs.) and center left
engine mount insulator. (5) Recheck drive shaft length.
ENGINE ASSEMBLY
REMOVAL
(1) Disconnect battery.
(2) Mark hood position at hinges and remove hood.
(3) Drain cooling system. Refer to Cooling System,
Group 7 for procedure. (4) Disconnect all electrical connections.
(5) Remove coolant hoses from radiator and engine.
(6) Remove radiator and fan assembly.
(7) See Fuel System, Group 14, to release fuel pres-
sure. Disconnect fuel lines and accelerator cable. (8) Remove air cleaner assembly.
(9) Hoist vehicle and drain engine oil.
(10) Remove air conditioning compressor mounting
bolts and set compressor aside. (11) Disconnect exhaust pipe at manifold.
(12) Remove transmission inspection cover and
mark flex plate to torque converter position. For disas-
sembly procedure for the all wheel drive vehicle refer to
Group 21 Transaxle. (13) Remove screws holding torque converter to
flex plate and attach C-clamp on bottom of converter
housing to prevent torque converter from counting
out. (14) Remove power steering pump mounting bolts
and set pump aside. (15) Remove two lower transmission to block
screws. (16) Remove starter.
(17) Lower vehicles and disconnect vacuum lines
and ground strap. (18) Install transmission holding fixture.
(19) Attach engine lifting hoist and support en-
gine. (20) Remove upper transmission case to block
bolts. (21) See Engine Mounting in (Fig. 3) and separate
mount/insulators as follows: (a) Mark RIGHT insulator on right rails sup-
ports. Remove insulator to rails screws. (b) Remove FRONT engine mount through bolt
and nut. (c) Remove LEFT insulator through bolt from in-
side wheelhouse or insulator bracket to transmis-
sion screws.
(22) Remove engine.
INSTALLATION
(1) Attach hoist and lower engine into engine com-
partment. (2) Align engine mounts and install but do not
tighten until all mounting bolts have been installed.
Tighten bolts to torque specified in (Fig. 3). (3) Install transmission case to cylinder block,
tighten bolts to 102 N Im (75 ft. lbs.) torque.
(4) Remove engine hoist and transmission holding
fixture. (5) Remove C-clamp from torque converter hous-
ing. Align flex plate to torque converter and install
mounting screws. Tighten to 75 N Im (55 ft. lb-
s.)torque. Refer to Group 21 transaxle for the all
wheel drive installation procedure. (6) Install transmission inspection cover.
(7) Connect exhaust system at manifold.
(8) Install starter.
(9) Install power steering pump and air condition-
ing compressor. For belt installation see Accessory
Belt Drive in Cooling System Group 7. (10) Lower vehicle and connect all vacuum lines.
(11) Connect all electrical connections including
ground strap. (12) Connect fuel lines and accelerator cable.
(13) Install radiator and fan assembly. Reconnect
fan motor electrical lead. Reinstall radiator hoses.
Fill cooling system. See Cooling System Group 7 for
filling procedure. (14) Fill engine crankcase with proper oil to cor-
rect level.
Fig. 4 Left Insulator Movement
Ä 3.3/3.8L ENGINE 9 - 101

2.2L/2.5L SINGLE POINT FUEL INJECTIONÐSYSTEM OPERATION INDEX
page page
Air Conditioning (A/C) Clutch RelayÐPCM Output.28
Air Conditioning Switch SenseÐPCM Input ..... 26
Auto Shutdown (ASD) Relay and Fuel Pump RelayÐPCM Output ..................... 29
Battery VoltageÐPCM Input ................ 26
Brake SwitchÐPCM Input .................. 26
EVAP Canister Purge SolenoidÐPCM Output . . . 29
CCD Bus .............................. 25
Coolant Temperature SensorÐPCM Input ...... 26
Data Link ConnectorÐPCM Output ........... 30
Distributor (Hall Effect) Pick-UpÐPCM Input .... 26
Electric Electronic Gas RecirculationÐPCM Output.30
Fuel InjectorÐPCM Output ................. 31
Fuel Pressure Regulator ................... 33
General Information ....................... 24
Generator FieldÐPCM Output ............... 31
Heated Oxygen Sensor (O
2Sensor)ÐPCM Input . 27
Idle Air Control MotorÐPCM Output .......... 29 Ignition CoilÐPCM Output
.................. 31
Malfunction Indicator Lamp (Check Engine)ÐPCM Output ............................... 30
Manifold Absolute Pressure (MAP) SensorÐPCM Input ................................ 27
Modes of Operation ....................... 32
Part Throttle Unlock SolenoidÐPCM Output .... 31
Powertrain Control Module ................. 25
Radiator Fan RelayÐPCM Output ............ 31
Speed Control SolenoidsÐPCM Output ........ 31
Speed ControlÐPCM Input ................. 27
System Diagnosis ........................ 25
TachometerÐPCM Output .................. 32
Throttle Body ............................ 33
Throttle Position Sensor (TPS)ÐPCM Input ..... 28
Transaxle Park/Neutral SwitchÐPCM Input ..... 28
Vehicle Speed SensorÐPCM Input ........... 28
GENERAL INFORMATION
The computer regulated, Electronic Fuel Injection
System (Fig. 1) provides a precise air/fuel ratio for
all driving conditions. The fuel injection system is
controlled by the powertrain control module (PCM).
The PCM is a pre-programmed digital computer. The
PCM regulates ignition timing, air-fuel ratio, emission
control devices, cooling fan, charging system, speed con-
trol, and idle speed. The PCM can adapt its requirement
to meet changing operating conditions.
Fig. 1 Electronic Fuel Injection Components
14 - 24 FUEL SYSTEMS Ä

Various sensors provide the inputs necessary for
the PCM to correctly regulate fuel flow at the fuel
injector. These include the manifold absolute pres-
sure, throttle position, oxygen sensor, coolant tem-
perature, and vehicle speed sensors. In addition to
the sensors, various switches and relays provide im-
portant information and system control. The inputs
include the park/neutral switch and air conditioning
clutch switch. The outputs include the auto shutdown
relay and fuel pump relay. All inputs to the PCM are converted into signals.
Based on these inputs the PCM adjusts air-fuel ratio,
ignition timing and other controlled outputs. The
PCM adjusts the air-fuel ratio by changing the injec-
tor pulse width. Injector pulse width is the period of
time the injector is energized.
SYSTEM DIAGNOSIS
The PCM tests many of its own input and output
circuits. If a fault is found in a major system, the in-
formation is stored in memory. Technicians can dis-
play fault information through the instrument panel
Malfunction Indicator lamp (instrument panel Check
Engine lamp) or by connecting the DRBII scan tool.
For diagnostic trouble code information, refer to On
Board Diagnostics in 2.2L/2.5L Single Point Fuel In-
jectionÐGeneral Diagnosis section of this group.
CCD BUS
Various modules exchange information through a
communications port called the CCD Bus. The pow-
ertrain control module (PCM) transmits vehicle load
data on the CCD Bus.
POWERTRAIN CONTROL MODULE
The powertrain control module (PCM) is a digital
computer containing a microprocessor (Fig. 2). The
PCM receives input signals from various switches
and sensors that are referred to as PCM Inputs.
Based on these inputs, the PCM adjusts various en-
gine and vehicle operations through devices that are
referred to as PCM Outputs. PCM Inputs:
² Air Conditioning Controls
² Battery Voltage
² Brake Switch
² Coolant Temperature Sensor
² Distributor (Hall Effect) Pick-up
² Manifold Absolute Pressure (MAP) Sensor
² Oxygen Sensor
² SCI Receive
² Speed Control System Controls
² Throttle Position Sensor
² Park/Neutral Switch (automatic transaxle)
² Vehicle Speed Sensor
PCM Outputs:
² Air Conditioning Clutch Relay
² Generator Field ²
Idle Air Control Motor
² Auto Shutdown (ASD) Relay
² Canister Purge Solenoid
² Malfunction Indicator (Check Engine) Lamp
² Data Link Connector (Diagnostic Connector)
² Electronic EGR Transducer
² Fuel Injector
² Ignition Coil
² Part Throttle Unlock Solenoid (Automatic Tran-
saxle)
² Radiator Fan Relay
² Speed Control Solenoids
² Tachometer Output
Based on inputs it receives, the PCM adjusts fuel
injector pulse width, idle speed, ignition spark ad-
vance, ignition coil dwell and canister purge opera-
tion. The PCM regulates operation of the EGR,
cooling fan, A/C and speed control systems. The PCM
changes generator charge rate by adjusting the gen-
erator field. The PCM adjusts injector pulse width (air-fuel ra-
tio) based on the following inputs.
² battery voltage
² coolant temperature
² exhaust gas content
² engine speed (distributor pick-up)
² manifold absolute pressure
² throttle position
The PCM adjusts ignition timing based on the fol-
lowing inputs.
² coolant temperature
² engine speed (distributor pick-up)
² manifold absolute pressure
² throttle position
The Auto Shutdown (ASD) and Fuel Pump relays
are mounted externally, but turned on and off by the
PCM through the same circuit. The distributor pick-up signal is sent to the PCM.
If the PCM does not receive a distributor signal
within approximately one second of engine cranking,
Fig. 2 PCM
Ä FUEL SYSTEMS 14 - 25

it de-activates the ASD relay and fuel pump relay.
When these relays are deactivated, power is shut off
from the fuel injector, fuel pump, ignition coil, and
oxygen sensor heater element. The PCM contains a voltage converter that
changes battery voltage to a regulated 8.0 volts to
power the distributor pick-up and vehicle speed sen-
sor. The PCM also provides a 5.0 volts supply for the
coolant temperature sensor, manifold absolute pres-
sure sensor and throttle position sensor.
AIR CONDITIONING SWITCH SENSEÐPCM INPUT
ALL VEHICLES EXCEPT AC-BODY
When the air conditioning or defrost switch is put
in the ON position and the low pressure and high
pressure switches are closed, the PCM receives an in-
put indicating that the air conditioning has been se-
lected. After receiving this input, the PCM activates
the A/C compressor clutch by grounding the A/C
clutch relay. The PCM also adjusts idle speed to a
scheduled RPM to compensate for increased engine
load.
AC-BODY VEHICLES
When the air conditioning or defrost switch is put
in the ON position and the low pressure switch, high
pressure switch and electronic cycling switch close,
the PCM receives an air conditioning select input.
After receiving this input, the PCM activates the
A/C compressor clutch by grounding the A/C com-
pressor clutch relay. The PCM also adjusts idle speed
to a scheduled RPM to compensate for increased en-
gine load.
BATTERY VOLTAGEÐPCM INPUT
The PCM monitors the battery voltage input to de-
termine fuel injector pulse width and generator field
control. If battery voltage is low, the PCM increases
injector pulse width.
BRAKE SWITCHÐPCM INPUT
When the brake switch is activated, the PCM re-
ceives an input indicating that the brakes are being
applied. After receiving the input, the PCM vents the
speed control servo. Venting the servo turns the
speed control system off.
COOLANT TEMPERATURE SENSORÐPCM INPUT
The coolant temperature sensor is installed behind
the thermostat housing and ignition coil in the hot
box. The sensor provides an input voltage to the
PCM (Fig. 3). As coolant temperature varies, the sen-
sors resistance changes, resulting in a different input
voltage to the PCM. The PCM demands slightly richer air-fuel mixtures
and higher idle speeds until the engine reaches nor-
mal operating temperature. This sensor is also used for cooling fan control.
DISTRIBUTOR (HALL EFFECT) PICK-UPÐPCM
INPUT
The distributor pick-up supplies engine speed to
the PCM. The distributor pick-up is a Hall Effect de-
vice (Fig. 4).
A shutter (sometimes referred to as an interrupter)
is attached to the distributor shaft. The shutter con-
tains four blades, one per engine cylinder. A switch
plate is mounted to the distributor housing above the
Fig. 3 Coolant Temperature Sensor
Fig. 4 Distributor Pick-UpÐTypical
14 - 26 FUEL SYSTEMS Ä

TRANSAXLE PARK/NEUTRAL SWITCHÐPCM
INPUT
The park/neutral switch is located on the auto-
matic transaxle housing (Fig. 7). Manual transaxles
do not use park neutral switches. The switch pro-
vides an input to the PCM. The input indicates
whether the automatic transaxle is in Park, Neutral,
or a drive gear selection. This input is used to deter-
mine idle speed (varying with gear selection), fuel in-
jector pulse width, and ignition timing advance. The
park neutral switch is sometimes referred to as the
neutral safety switch.
THROTTLE POSITION SENSOR (TPS)ÐPCM INPUT
The Throttle Position Sensor (TPS) is mounted on
the throttle body and connected to the throttle blade
shaft (Fig. 8). The TPS is a variable resistor. The
sensor provides an input signal (voltage) to the PCM
representing throttle blade position. As the position
of the throttle blade changes, the resistance of the
TPS changes.
The PCM supplies approximately 5 volts to the
TPS. The TPS output voltage (input signal to the
PCM) represents the throttle blade position. The
PCM receives an input signal voltage from the TPS
varying in an approximate range of from 1 volt at
minimum throttle opening (idle) to 4 volts at wide open throttle. Along with inputs from other sensors,
the PCM uses the TPS input to determine current
engine operating conditions. The PCM adjusts fuel
injector pulse width and ignition timing based on
these inputs.
VEHICLE SPEED SENSORÐPCM INPUT
The vehicle speed sensor is located in the transaxle
extension housing (Fig. 9). The sensor input is used
by the PCM to determine vehicle speed and distance
traveled.
The speed sensor generates 8 pulses per sensor rev-
olution. These signals, along with a closed throttle
signal from the TPS, determine if a closed throttle
deceleration or normal idle condition (vehicle
stopped) exists. Under deceleration conditions, the
PCM adjusts the idle air control motor to maintain a
desired MAP value. Under idle conditions, the PCM
adjusts the idle air control motor to maintain a de-
sired engine speed.
AIR CONDITIONING (A/C) CLUTCH RELAYÐPCM
OUTPUT
The PCM operates the air conditioning clutch relay
ground circuit. The radiator fan relay supplies bat-
tery power to the solenoid side of the A/C clutch re-
lay. The air conditioning clutch relay will not
energize unless the radiator fan relay energizes. The
PCM energizes the radiator fan relay when the air
conditioning or defrost switch is put in the ON posi-
tion and the low pressure and high pressure switches
close. With the engine operating, the PCM cycles the air
conditioning clutch on and off when the A/C switch
closes with the blower motor switch in the on posi-
tion. When the PCM senses low idle speeds or wide
open throttle through the throttle position sensor, it
de-energizes the A/C clutch relay. The relay contacts
open, preventing air conditioning clutch engagement.
Fig. 7 Park/Neutral Switch
Fig. 8 Throttle Position Sensor
Fig. 9 Vehicle Distance (Speed) SensorÐTypical
14 - 28 FUEL SYSTEMS Ä