1993 CHEVROLET PLYMOUTH ACCLAIM ECU

against modulator assembly. Then torque proportion-
ing valve to 35 N Im (26 ft. lbs.) torque.
(3) Install hydraulic brake line on proportioning
valve and hand start tube nut into proportioning valve.
Torque tube nut to 18 N Im (159 in. lbs.) torque.
(4) Using approved battery jumper cables, attach
battery, to the vehicles negative and positive battery
cables (Fig. 8). (5) Bleed the vehicles base brake and Antilock brake
hydraulic systems. Refer to Bleeding Bendix Antilock 4
Brake System in this service manual supplement for
required bleeding procedure. (6) Install battery acid shield (Fig. 9) onto the ABS
modulator assembly. Be sure acid shield is securely
attached to modulator assembly before installing
battery tray.
(7) Install battery tray in vehicle. Then install the 4
bolts (Fig. 10) attaching battery tray to inner fender
and frame rail. Torque the 4 battery tray attaching
bolts to 20 N Im (175 in.lbs.).
(8) If equipped, install speed control vacuum reser-
voir on battery tray. Install the 2 speed control vacuum
reservoir attaching bolts (Fig. 11). Torque the 2
vacuum reservoir attaching bolts to 4 N Im (30 in. lbs.).
(9) Install battery tray access cover (Fig. 12) on
bottom of battery tray. The access cover MUST be
on battery tray, before battery is installed in
battery tray.
Fig. 8 Battery Connected To Vehicle For Bleeding Modulator Assembly
Fig. 7 Proportioning Valve Removal From Modulator Assembly
Fig. 9 Modulator Assembly Acid Shield Installed
Fig. 10 Battery Tray Installation And Attaching Bolts
5 - 40 ANTILOCK 4 BRAKE SYSTEM Ä

(10) Install battery on battery tray and install and
securely tighten the battery hold down clamp (Fig.
13). Then install heat shield, on battery (Fig. 13). (11) Install battery cables on battery. Securely
tighten clamping bolts on battery cable terminals. (12) Reset any electrical components of the vehicle
which were affected by the removal of the battery. (13) Road test vehicle to verify correct operation of
the vehicles's base and Antilock brake systems.
ELECTRONIC COMPONENTS
CONTROLLER ANTILOCK BRAKE CAB
REMOVE
(1) Turn vehicle ignition off.
(2) Disconnect the wiring harness connector from
the Antilock system relay (Fig. 1). Relay will be re-
moved as part of the CAB bracket.
CAUTION: BEFORE REMOVING 60 WAY CONNEC-
TOR FROM THE CAB VERIFY THAT THE VEHICLE'S
IGNITION IS IN THE OFF OR LOCK POSITION. IF IG-
NITION IS ON WHEN 60 WAY CONNECTOR IS RE-
MOVED FROM THE CAB DAMAGE TO THE
CONTROLLER COULD OCCUR.
(3) Loosen bolt (Fig. 2) retaining the wiring har-
ness 60 way connector to the CAB. Then disconnect
the 60 way connector (Fig. 2) from the CAB by pull-
ing it straight out, do not twist connector when re-
moving. (4) Remove the 2 bolts (Fig. 3) attaching the CAB
module mounting bracket, to the frame rail of the ve-
hicle. (5) Remove the CAB and its mounting bracket as
an assembly from the vehicle from the vehicle. (6) Remove the 3 screws (Fig. 4) attaching the
CAB to the CAB mounting bracket. Then separate
CAB from mounting bracket.
Fig. 11 Vacuum Reservoir Installation And Attaching Bolts
Fig. 12 Battery Tray Access Shield Installed
Fig. 13 Battery Hold Down Clamp And Heat Shield Installed
Fig. 1 CAB Location
Ä ANTILOCK 4 BRAKE SYSTEM 5 - 41

ENGINE BLOCK HEATER
DESCRIPTION AND OPERATION
On all models an engine block heater is available as
an optional accessory. The heater, operated by ordinary
house current (110 Volt A.C.) through a power cord and
connector behind the radiator grille, provides easier
engine starting and faster warm-up when vehicle is
operated in areas having extremely low temperatures.
The heater is mounted in a core hole (in place of a core
hole plug) in the engine block, with the heating ele-
ment immersed in coolant (Fig. 9). The power cord must be secured in its retainer
clips, and not positioned so it could contact link-
ages or exhaust manifolds and become damaged. If unit does not operate, trouble can be in either the
power cord or the heater element. Test power cord for
continuity with a 110-volt voltmeter or 110-volt test
light; test heater element continuity with an ohmmeter
or 12-volt test light.
REMOVAL
(1) Drain coolant from radiator and cylinder block.
Refer to Cooling System Drain, Clean, Flush and Re-
fill of this section for procedure. (2) Detach power cord plug from heater.
(3) Loosen screw in center of heater. Remove
heater assembly.
INSTALLATION
(1) Thoroughly clean core hole and heater seat.
(2) Insert heater assembly with element loop posi-
tioned upward.
(3) With heater seated, tighten center screw se-
curely to assure a positive seal. (4) Fill cooling system with coolant to the proper
level, vent air, and inspect for leaks. Pressurize sys-
tem with Radiator Pressure Tool before looking for
leaks.
Fig. 9 Engine Block Heater
7 - 28 COOLING SYSTEM Ä

STARTER CONTROL CIRCUIT TESTS
The starter control circuit has:
² Starter solenoid
² Starter relay (Fig. 2)
² Neutral starting and back-up switch with auto-
matic transmissions
² Clutch pedal mounted starter interlock switch
with manual transmissions
² Ignition switch
² Battery
² All related wiring and connections
CAUTION: Before performing any starter tests, the
ignition system must be disabled.
² VEHICLES EQUIPPED WITH A CONVEN-
TIONAL DISTRIBUTOR: Disconnect coil wire from
distributor cap center tower. Secure wire to a good
ground to prevent engine from starting (Fig. 6).
² VEHICLES EQUIPPED WITH DIRECT IGNI-
TION SYSTEM: Unplug the coils electrical connector
(Fig. 7).
STARTER SOLENOID TEST
WARNING: CHECK TO ENSURE THAT THE TRANS-
MISSION IS IN PARK OR NEUTRAL WITH THE
PARKING BRAKE APPLIED
(1) Verify battery condition. Battery must be in
good condition with a full charge before performing
any starter tests. Refer to Battery Tests. (2) Perform this starter solenoid test BEFORE per-
forming the starter relay test. (3) Raise the vehicle.
(4) Perform a visual inspection of the starter/
starter solenoid for corrosion, loose connections or
faulty wiring. (5) Lower the vehicle.
(6) Locate the starter relay as follows:
² On AC, AG, AJ and AY Bodies the relay is located
in the Power Distribution Center. This Center is mounted near the front of the left front strut tower
(Fig. 13). The position of the starter relay within this
Center will be shown on the Center cover.
² On AA/AP Bodies the relay is located on the front
of the left front strut tower (Fig. 14).
(7) Remove the starter relay from the connector.
(8) Connect a remote starter switch or a jumper
wire between the battery positive post and terminal
87 on the starter relay connector. To decide the
starter relay terminal numbers, refer to the Starter
Relay Tests.
² If engine now cranks, starter/starter solenoid is
good. Go to the starter relay test.
² If engine does not crank with this test, or solenoid
chatters, check wiring and connectors from starter
Fig. 12 Test Positive Battery Cable Resistance
Fig. 13 Starter Relay LocationÐAC, AG, AJ, and AY Bodies
Fig. 14 Starter Relay LocationÐAA/AP Body
Ä BATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICS 8A - 15

(5) Remove the battery from vehicle.
(6) Clean top of battery with a solution of warm
water and baking soda. Apply solution with a bristle
brush and allow to soak until acid deposits loosen
(Fig. 4). Rinse with clear water and blot dry with pa-
per toweling. Dispose of toweling in a safe manner.
Refer to the WARNINGS on the top of battery.
CAUTION: Do not allow baking soda solution to en-
ter vent holes, as damage to battery can result.
(7) Inspect battery case and cover for cracks or
leakage. If leakage is present, battery must be re-
placed. (8) Inspect battery tray (Fig. 5) for damage caused
by acid from battery. If acid damage is present, it
will be necessary to clean area with same solution
described in Step (6). (9) Clean battery posts with a suitable battery post
cleaning tool (Fig. 6). (10) Clean inside surfaces of battery cable terminal
clamps with a suitable battery terminal cleaning tool
(Fig. 7). Replace damaged or frayed cables and bro-
ken terminal clamps. (11) Inspect battery for proper or damaged hold
down ledge. (12) Install battery in vehicle making sure that
battery is positioned properly on battery tray (Fig.
3). (13) Install battery hold down clamp and nut. Be
sure that clamp is positioned properly and aligned on
battery. (14) Install battery heat shield.
(15) Place felt grease washer onto Positive (+) bat-
tery post. (16) Connect battery cable clamps to battery posts
making sure top of clamp is flush with top of post
(Fig. 8). Install POSITIVE cable first. (17) Tighten clamp nuts securely.
Fig. 4 Cleaning Battery
Fig. 5 Battery Tray
Fig. 6 Cleaning Battery Posts
8B - 2 BATTERY/STARTER/GENERATOR SERVICE Ä

BOSCH STARTER GEAR AND CLUTCH REPLACEMENT
(1) Remove solenoid assembly (Fig. 18).
(2) Remove the two through-bolts securing the
starter drive end housing to the motor housing (Fig.
19) and separate housings. (3) Remove rubber seal (Fig. 20). (4) Pull the gear and clutch assembly from the
drive end housing (Fig. 21). (5) For installation, reverse above procedures.
STARTER INTERLOCK SWITCH: CLUTCH PEDAL
MOUNTED/MANUAL TRANSMISSION ONLY
For electrical diagnostics, refer to Group 8A, Bat-
tery/Starting/Charging Systems Diagnostics, Starter
relays.
Fig. 13 Gear and Clutch Assembly
Fig. 14 Field Terminal Nut
Fig. 15 Field Coil Terminal
Fig. 16 Field Terminal Washer
Fig. 17 Solenoid Mounting Screws
Fig. 18 Solenoid
Ä BATTERY/STARTER/GENERATOR SERVICE 8B - 7

BUS ACCESSED DIAGNOSTICS
The following diagnostic test may be used to check
the integrity of the EVIC's internal connections and
operations. Refer to the Body Chassis Diagnostic Test
Procedure Manual for test procedures. MODULE RESET TEST, when the EVIC receives
this request from the DRB II, the EVIC will immedi-
ately enter into reset. DISPLAY TEST: The EVIC receives a request from
the DBR II, the EVIC will enter into a visual display
mode. Also checks the integrity of the display driver
to anode connections. The test shall consist of walk-
ing through the vertical and horizontal rows of an-
odes in the dot matrix display. SWITCH STATUS TEST, when the EVIC receives
this request from the DRB II, the EVIC will report
the open/closed status of each individual switch. FAULT BYTE TEST, when the EVIC receives this
request from the DRB II, the EVIC will report fault
status. Messages reported are:
² NO FAULT
² DISPLAY DRIVER FAULT
² EVIC MISSING MESSAGES
² POWER SUPPLY FAILURE
² FAULT IN RAM
² FAULT IN ROM
EVIC missing message implies that there may be a
system failure and/or the body controller is not pro-
viding EVIC with sufficient information. DISPLAY DRIVER FAULT, power supply failure
and fault in RAM/ROM implies that the EVIC is de-
fective.
CONSOLE REMOVAL
(1) Remove lenses (Fig. 4).
(2) Remove screws from visor tip-pin retainers.
(3) Remove screws in lens openings, after remov-
ing lamps. (4) Remove console and disconnect wires.
(5) For installation reverse above procedures.
ELECTRONIC BOARD ASSEMBLY REPLACEMENT
(1) Remove console, refer to Console Replacement
(Fig. 5).
(2) Remove six mounting screws holding bezel to
housing. (3) Remove switch assembly by pulling down
mounting tabs and swing assembly out of position. (4) Disconnect switch wiring connector and replace
electronic board assembly. (5) For installation reverse above procedures.
BEZEL/BUTTON SWITCH REMOVAL
(1) Remove console, refer to Console Replacement.
(2) Remove six mounting screws holding bezel to
housing. (3) Remove switch assembly by pulling down
mounting tabs and swing assembly out of position. (4) Disconnect switch wiring connector and remove
electronic board and switch assembly. Replace func-
tion button switch assembly. The buttons are not ser-
viceable. (5) For installation reverse above procedures.
WIRING HARNESS REMOVAL
(1) Remove console, refer to Console Replacement
(Fig. 6). (2) Disconnect wiring connector from retaining
bracket. (3) Remove screws, securing wiring to console
housing. (4) Remove push/slide switches. The reading lamp
switch buttons are not serviceable. (5) Remove lamp sockets from reflector bracket.
(6) Remove wiring.
(7) For installation reverse above procedures.
Fig. 4 EVIC Overhead Console Lens Removal
Fig. 5 EVIC Overhead Console
8C - 10 OVERHEAD CONSOLE Ä

ing, detonation and cooling system malfunctions also
can cause spark plug overheating.
SPARK PLUG SERVICE
When replacing the spark plug and coil cables,
route the cables correctly and secure them in the ap-
propriate retainers. Failure to route the cables prop-
erly can cause the radio to reproduce ignition noise,
cross ignition of the spark plugs or short circuit the
cables to ground.
SPARK PLUG REMOVAL
Always remove the spark plug cable by grasping at
the spark plug boot turning, 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.
POWERTRAIN CONTROL MODULE (PCM)
The ignition system is regulated by the powertrain
control module (PCM) (Fig. 14). The PCM supplies
battery voltage to the ignition coil through the Auto
Shutdown (ASD) Relay. The PCM also controls the
ground circuit for the ignition coil. By switching the ground path for the coil on and off, the PCM adjusts
ignition timing to meet changing engine operating
conditions.
During the crank-start period the PCM advances
ignition timing a set amount. During engine opera-
tion, the amount of spark advance provided by the
PCM is determined by these input factors:
² coolant temperature
² engine RPM
² available manifold vacuum
The PCM also regulates the fuel injection system.
Refer to the Fuel Injection sections of Group 14.
DISTRIBUTOR PICK-UPÐPCM INPUT
The engine speed input is supplied to the power-
train control module (PCM) by the distributor pick-
up. The distributor pick-up is a Hall Effect device
(Fig. 15 or Fig. 16).
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
shutter. The switch plate contains the distributor
Fig. 14 Powertrain control module (PCM)
Fig. 15 DistributorÐ2.2L and 2.5L TBI Engines
Fig. 13 Spark Plug Overheating
8D - 6 IGNITION SYSTEMS Ä