fuses DODGE NEON 1999 Service User Guide

HEADLAMP DIAGNOSIS
Always begin any diagnosis by testing all of the fuses and circuit breakers in the system. Refer to Group 8W,
Wiring Diagrams.
Conventional and halogen headlamps are interchangeable. It is recommended that they not be intermixed on
a given vehicle.
CONDITION POSSIBLE CAUSES CORRECTION
HEADLAMPS ARE DIM
WITH ENGINE IDLING1. Loose or corroded battery cables. 1. Clean and secure battery cable clamps
and posts.
OR IGNITION TURNED
OFF2. Loose or worn generator drive
belt.2. Adjust or replace generator drive belt.
3. Charging system output too low. 3. Test and repair charging system, refer to
Group 8A,
4. Battery has insufficient charge. 4. Test battery state-of-charge,
refer to Group 8A.
5. Battery is sulfated or shorted. 5. Load test battery, refer to Group 8A.
6. Poor lighting circuit Z1-ground. 6. Test for voltage drop across Z1-ground
locations, refer to Group 8W.
7. Both headlamp bulbs defective. 7. Replace both headlamp bulbs.
HEADLAMP BULBS
BURN OUT1. Charging system output too high. 1. Test and repair charging system, refer to
Group 8A.
FREQUENTLY 2. Loose or corroded terminals or
splices in circuit.2. Inspect and repair all connectors and
splices, refer to Group 8W.
HEADLAMPS ARE DIM
WITH ENGINE RUNNING1. Charging system output too low. 1. Test and repair charging system, refer to
Group 8A.
ABOVE IDLE* 2. Poor lighting circuit Z1-ground. 2. Test for voltage drop across Z1-ground
locations, refer to Group 8W.
3. High resistance in headlamp
circuit.3. Test amperage draw of headlamp circuit.
4. Both headlamp bulbs defective. 4. Replace both headlamp bulbs.
HEADLAMPS FLASH
RANDOMLY1. Poor lighting circuit Z1-ground. 1. Test for voltage drop across Z1-ground
locations, refer to Group 8W.
2. High resistance in headlamp
circuit.2. Test amperage draw of headlamp circuit.
Should not exceed 30 amps.
3. Faulty headlamps switch circuit
breaker.3. Replace headlamp switch.
4. Loose or corroded terminals or
splices in circuit.4. Inspect and repair all connectors and
splices, refer to Group 8W.
HEADLAMPS DO NOT
ILLUMINATE1. No voltage to headlamps. 1. Repair open headlamp circuit, refer to
Group 8W.
2. No Z1-ground at headlamps. 2. Repair circuit ground, refer to Group 8W.
3. Faulty headlamp switch. 3. Replace headlamp switch.
4. Faulty headlamp dimmer
(multi-function) switch.4. Replace multi-function switch.
5. Broken connector terminal or wire
splice in headlamp circuit.5. Repair connector terminal or wire splice.
1. Headlamps stay on with
key out (DRLM equipped
vehicles).1. Failed DRLM 1. Replace DRLM.
*Canada vehicles must have lamps ON.
8L - 2 LAMPSPL
DIAGNOSIS AND TESTING (Continued)

Instrument Panel and Systems for removal proce-
dures.
(2) Turn the ignition switch ON.
(3) Using a voltmeter, check for battery voltage at
Pin 3 and Pin 4 (Fig. 3), (Fig. 4).
(a) If OK, go to Step 4.
(b) If NOT OK, check fuse 8 in fuse block and
the 30 Amp maxi fuse in the Power Distribution
Center (PDC). If fuses are OK, check wiring cir-
cuit. Refer to Group 8W, Wiring Diagrams.
(4) Check Pin 5, with switch in the ON position
there should be battery voltage and no voltage in the
OFF position.
(a) If OK, go to Step 5.
(b) If NOT OK, no voltage in the ON position or
voltage in the OFF position. Replace the switch/re-
lay module.
(5) Press switch to ON position. The indicator
lamp should come on and remain on for approxi-
mately 10 minutes. If the indicator lamp fails to light
or no voltage is present for approximately 10 min-
utes. Replace Rear Window Defogger Switch.
(6) To bench test relay:
(a) Using a jumper wire connect a 12 volt batter
supply, apply voltage to Pin 3 and 4. Ground Pin 2.
(b) Follow the above procedures except Step 2
SERVICE PROCEDURES
GRID LINE AND TERMINAL REPAIR
WARNING: REPAIR KIT MAY CAUSE SKIN OR EYE
IRRITATION. CONTAINS EPOXY RESIN AND AMINE
TYPE HARDENER, HARMFUL IF SWALLOWED.
AVOID CONTACT WITH SKIN AND EYES. FOR SKIN,
WASH AFFECTED AREAS WITH SOAP AND WATER.
DO NOT TAKE INTERNALLY. IF TAKEN INTER-
NALLY, INDUCE VOMITING; CALL A PHYSICIAN
IMMEDIATELY. IF IN CONTACT WITH EYES, FLUSH
WITH PLENTY OF WATER. USE WITH ADEQUATEVENTILATION. DO NOT USE NEAR FIRE OR FLAME.
CONTENTS CONTAIN 3 PERCENT FLAMMABLE
SOLVENTS.
KEEP OUT OF REACH OF CHILDREN.
The repair of the grid lines or the terminal is pos-
sible using the MopartRepair Package or equiva-
lent.
(1) Mask repair area so conductive epoxy can be
extended onto the line or the bus bar (Fig. 5).
(2) Follow instructions in repair kit for preparing
damaged area.
(3) Remove package separator clamp and mix plas-
tic conductive epoxy thoroughly. Fold in half and cut
center corner to dispense epoxy.
(4) For grid line, mark off area to be repaired with
masking tape or a template (Fig. 5).
(5) Apply conductive epoxy through slit in masking
tape. Overlap both ends of the break by 19 mm (3/4
inch).
(6) For a terminal or pigtail replacement, mask
adjacent areas so epoxy can be extended onto line as
well as bus bar. Apply a thin layer of epoxy to area
where terminal was fastened and to adjacent line.
(7) Apply a thin layer of conductive epoxy on ter-
minal and place terminal on desired location. To pre-
vent terminal from moving while the epoxy is curing,
it must be wedged or clamped.
(8) Carefully remove masking tape from grid line.
CAUTION: Do not allow the glass surface to
exceed 204ÉC (400ÉF), glass may fracture.
(9) Allow epoxy to cure 24 hours at room tempera-
ture or use heat gun with a 260Éto 371ÉC (500É to
700ÉF) range for 15 minutes. Hold gun approximately
254 mm (10 inches) from repaired area.
(10) After conductive epoxy is properly cured
remove wedge from terminal and check out operation
of rear window defogger. Do not attach connectors
until curing is complete.
Fig. 4 Rear Window Defogger Switch
Fig. 5 Grid Line Repair
PLELECTRICALLY HEATED SYSTEMS 8N - 3
DIAGNOSIS AND TESTING (Continued)

ELECTRICALLY HEATED SYSTEMS
CONTENTS
page page
DIAGNOSIS AND TESTING
REAR WINDOW DEFOGGER SWITCH....... 1REMOVAL AND INSTALLATION
REAR WINDOW DEFOGGER AND/OR REAR
FOG LAMP SWITCH................... 2
DIAGNOSIS AND TESTING
REAR WINDOW DEFOGGER SWITCH
The rear window defogger switch may be tested in-
vehicle or bench tested. In vehicle testing is accom-
plished in the following manner:
(1) Remove the switch from the instrument panel
but leave the switch connected, refer to Group 8E,
Instrument Panel and Systems for removal proce-
dures.
(2) Turn the ignition switch ON.
(3) Using a voltmeter, check for battery voltage at
Pin 3 and Pin 4 (Fig. 1) and (Fig. 2).
(a) If OK, go to Step 4.
(b) If NOT OK, check fuse 8 in fuse block and
the 30 Amp maxi fuse in the Power Distribution
Center (PDC). If fuses are OK, check wiring cir-
cuit. Refer to Group 8W, Wiring Diagrams.
(4) Check Pin 5, with switch in the ON position
there should be battery voltage and no voltage in the
OFF position.
(a) If OK, go to Step 5.
(b) If NOT OK, no voltage in the ON position or
voltage in the OFF position. Replace the switch/re-
lay module.
(5) Press switch to ON position. The indicator
lamp should come on and remain on for approxi-
mately 10 minutes. If the indicator lamp fails to light
or no voltage is present for approximately 10 min-
utes. Replace Rear Window Defogger Switch.
(6) To bench test relay:
(a) Using a jumper wire connect a 12 volt batter
supply, apply voltage to Pin 3 and 4. Ground Pin 2.
(b) Follow the above procedures except Step 2
Fig. 1 Systems Electrical Circuit
PLELECTRICALLY HEATED SYSTEMS 8N - 1

parking lamps out put. Press the panic button and
check for a voltage pulse (Fig. 2).
(2) If no voltage pulse is measured, replace the
receiver. If voltage OK, repair circuit to the parking
lamps as necessary.
(3) Connect the meter to Pin 5 of the black connec-
tor and to ground to test head lamps out put. Press
the panic button and check for a voltage pulse (Fig.
2).
(4) If no voltage pulse is measured, replace the
receiver. If voltage OK, repair circuit to the head
lamps as necessary.
REMOTE KEYLESS ENTRY SYSTEM
When trouble shooting problems with the Remote
Keyless Entry System, always verify that the power
door lock/unlock switches are functional. If the doors
do not lock/unlock refer to Group 8W, Wiring Dia-
gram for Pin and wiring locations.
If the following items do not work:
²Remote keyless entry system
²Radio/clock
²Door lock switches
A blown fuse is the probable cause. Check fuses 2,
3 and 11 in the fuse block. To check for a blown fuse,
pull the fuse out slightly, but maintain contact
between the fuse terminals and the terminals in fuse
block. Using the voltmeter probe, check both termi-
nals for 12 volts. If only one terminal measures bat-
tery voltage, the circuit breaker is defective and must
be replaced. If neither terminal measures battery
voltage, check the high current fuses 3 and 11 in the
Power Distribution Center (PDC). The PDC is located
in the engine compartment. If fuse(s) are NOT OK,
replace fuse(s) or repair as necessary. If fuses are
OK, check for an open or shorted circuit to the Power
Distribution Center, repair as needed.
SERVICE PROCEDURES
HORN CHIRP CANCELLATION
During the programming operation the horn chirp
can be disabled or enable using the following proce-
dure. One or both transmitters can be program to be
disabled or enable.
(1) Retrieve the programming line from the upper
edge of the passenger side cowl trim panel upper
edge. The RKE Programming Line is a green wire
with a red bullet connector.
(2) Using a jumper wire, ground the RKE pro-
gramming line.
(3) Turn ignition switch to the ON position.
(4) Press any button on the transmitter. The locks
will cycle to confirm programming,
(5) To disable or enable horn chirp press the lock
button on the transmitter four times and the hornwill sound to confirm programming. Press the lock
button on the second transmitter four times and the
horn will sound to confirm programming.
(6) Disconnect the programming line from ground.
This returns the system to its normal operation
mode.
(7) Replace any removed components. Return pro-
gramming line chirpto its original position. Check for
system operation.
PANIC FUNCTION CANCELLATION
During the programming operation the panic func-
tion can be disabled or enable using the following
procedure. One or both transmitters can be program
to be disabled or enable.
(1) Retrieve the programming line from the upper
edge of the passenger side cowl trim panel. The RKE
Program Line is a green wire with a red bullet con-
nector.
(2) Using a jumper wire, ground the RKE Pro-
gramming Line.
(3) Turn ignition switch to the ON position.
(4) Press any button on the transmitter. The locks
will cycle to confirm programming,
(5) To disable or enable panic function press the
panic button on the transmitter four times and the
horn will sound to confirm programming. Press the
panic button on the second transmitter four times
and the horn will sound to confirm programming.
(6) Disconnect the programming line from ground.
This returns the system to its normal operation
mode.
(7) Replace any removed components. Return the
programming line to its original position. Check for
system operation.
PROGRAM REMOTE KEYLESS ENTRY MODULE
(1) Retrieve the programming line from the upper
edge of the passenger side cowl trim panel. The RKE
Programming Line is a green wire with a red bullet
connector.
(2) Using a jumper wire, ground the RKE pro-
gramming line.
(3) Turn ignition switch to the ON position.
(4) Press any button on the transmitter to set
code. The locks will cycle to confirm programming. If
there is a second transmitter it must be set at this
time. Press any button on the second transmitter and
wait for the locks to cycle to confirm programming.
(5) Disconnect the programming line from ground.
This returns the system to its normal operation
mode.
(6) Replace all removed components. Return pro-
gramming line to its original position. Check for sys-
tem operation.
PLPOWER DOOR LOCKS 8P - 5
DIAGNOSIS AND TESTING (Continued)

TESTING FOR A SHORT TO GROUND
(1) Remove the fuse and disconnect all items
involved with the fuse.
(2) Connect a test light or a voltmeter across the
terminals of the fuse.
(3) Starting at the fuse block, wiggle the wiring
harness about six to eight inches apart and watch
the voltmeter/test lamp.
(4) If the voltmeter registers voltage or the test
lamp glows, there is a short to ground in that gen-
eral area of the wiring harness.
TESTING FOR A SHORT TO GROUND ON
FUSES POWERING SEVERAL LOADS
(1) Refer to the wiring diagrams and disconnect or
isolate all items on the suspected fused circuits.
(2) Replace the blown fuse.
(3) Supply power to the fuse by turning ON the
ignition switch or re-connecting the battery.
(4) Start connecting the items in the fuse circuit
one at a time. When the fuse blows the circuit with
the short to ground has been isolated.
TESTING FOR A VOLTAGE DROP
(1) Connect the positive lead of the voltmeter to
the side of the circuit closest to the battery (Fig. 8).
(2) Connect the other lead of the voltmeter to the
other side of the switch or component.
(3) Operate the item.
(4) The voltmeter will show the difference in volt-
age between the two points.
TROUBLESHOOTING WIRING PROBLEMS
When troubleshooting wiring problems there are
six steps which can aid in the procedure. The steps
are listed and explained below. Always check for non-
factory items added to the vehicle before doing any
diagnosis. If the vehicle is equipped with these items,
disconnect them to verify these add-on items are not
the cause of the problem.
(1) Verify the problem.
(2) Verify any related symptoms. Do this by per-
forming operational checks on components that are
in the same circuit. Refer to the wiring diagrams.
(3) Analyze the symptoms. Use the wiring dia-
grams to determine what the circuit is doing, where
the problem most likely is occurring and where the
diagnosis will continue.
(4) Isolate the problem area.
(5) Repair the problem.
(6) Verify proper operation. For this step check for
proper operation of all items on the repaired circuit.
Refer to the wiring diagrams.
SERVICE PROCEDURES
WIRING REPAIR
When replacing or repairing a wire, it is important
that the correct gage be used as shown in the wiring
diagrams. The wires must also be held securely in
place to prevent damage to the insulation.
(1) Disconnect battery negative cable
(2) Remove 1 inch of insulation from each end of
the wire.
(3) Place a piece of heat shrink tubing over one
side of the wire. Make sure the tubing will be long
enough to cover and seal the entire repair area.
(4) Spread the strands of the wire apart on each
part of the exposed wire (example 1). (Fig. 9)
(5) Push the two ends of wire together until the
strands of wire are close to the insulation (example
2) (Fig. 9)
(6) Twist the wires together (example 3) (Fig. 9)
(7) Solder the connection together using rosin core
type solder only.Do not use acid core solder.
(8) Center the heat shrink tubing over the joint,
and heat using a heat gun. Heat the joint until the
tubing is tightly sealed and sealant comes out of both
ends of the tubing.
(9) Secure the wire to the existing ones to prevent
chafing or damage to the insulation
(10) Connect battery and test all affected systems.
TERMINAL/CONNECTOR REPAIR-MOLEX
CONNECTORS
(1) Disconnect battery.
Fig. 8 Testing for Voltage Drop
8W - 01 - 10 8W - 01 GENERAL INFORMATIONPL
DIAGNOSIS AND TESTING (Continued)

8W-02 COMPONENT INDEX
Component Page
A/C Compressor Clutch..................8W-42
A/C Compressor Clutch Relay.............8W-42
A/C Cycling Switch.....................8W-42
A/C Heater Blower Motor................8W-42
A/C Heater Control.....................8W-42
A/C Pressure Switches...................8W-42
ABS Warning Lamp Relay................8W-35
Airbag Control Module...................8W-43
Airbags..............................8W-43
Antenna..............................8W-47
Ash Receiver Lamp.....................8W-44
Automatic Shut Down Relay..............8W-30
Back-Up Lamp Switch...................8W-51
Back-Up Lamps........................8W-51
Battery..............................8W-20
Battery Temperature Sensor..............8W-30
Blower Motor Resistor Block..............8W-42
Brake Warning Lamp Switch...........8W-40, 50
Camshaft Position Sensor................8W-30
Center High Mounted Stop Lamp..........8W-51
Cigar Lighter Relay.....................8W-41
Cigar Lighter/Power Outlet...............8W-41
Circuit Breakers.......................8W-11
Clockspring.....................8W-30, 41, 61
Clutch Pedal Position Switch...........8W-10, 21
Combination Flasher....................8W-52
Controller Anti-Lock Brake...............8W-35
Crankshaft Position Sensor...............8W-30
Data Link Connector....................8W-30
Daytime Running Lamp Module...........8W-50
Diode No. 1........................8W-15, 42
Diode No. 2......................8W-10, 11, 44
Diode No. 3......................8W-11,44,70
Dome Lamp...........................8W-44
Door Ajar Switches.....................8W-44
Door Jamb Switches....................8W-44
Door Lock Motors......................8W-61
Door Lock Motors......................8W-61
Door Lock Switches.....................8W-61
Duty Cycle Evap/Purge Solenoid...........8W-30
EGR Transducer Solenoid................8W-30
Engine Coolant Temperature Sensor........8W-30
Engine Oil Pressure Switch...............8W-40
Engine Starter Motor....................8W-21
Engine Starter Motor Relay...............8W-21
Fog Lamp Relays....................8W-50, 51
Fog Lamp Switches..................8W-50, 51
Fog Lamps.........................8W-50, 51
Fuel Injectors..........................8W-30
Fuel Pump Module.....................8W-30
Fuel Pump Relay.......................8W-30
Fuse Block............................8W-11Component Page
Fuses (FB)............................8W-11
Fuses (PDC)...........................8W-10
Fusible Link........................8W-20, 21
Generator.............................8W-20
Glove Box Lamp And Switch..............8W-44
Grounds..............................8W-15
Halo Lamp............................8W-44
Headlamp Dimmer And Optical Horn Switch .8W-50
Headlamp Leveling Motors...............8W-50
Headlamp Leveling Switch...............8W-50
Headlamp Switch.......................8W-50
Headlamps............................8W-50
High Speed Warning Module..............8W-40
Horn Relay...........................8W-41
Horn Switches.........................8W-41
Horns................................8W-41
IAT/Map Sensor........................8W-30
Idle Air Control Motor...................8W-30
Ignition Coil Pack......................8W-30
Ignition Switch........................8W-10
Illumination Lamps.....................8W-40
Immobilizer...........................8W-61
Immobilizer Engine Sensor............8W-30, 61
Indicator Lamps........................8W-40
Instrument Cluster.....................8W-40
Intermittent Wipe/Wash Switch............8W-53
Key-In Switch.........................8W-40
Knock Sensor..........................8W-30
License Lamps.........................8W-51
Map/Reading Lamps....................8W-44
Noise Supressor.....................8W-10, 30
Oxygen Sensors........................8W-30
Park Brake Switch...................8W-40, 50
Park/Neutral Position Switch...........8W-30, 51
Park/Turn Signal Lamps..............8W-50, 52
Power Distribution Center................8W-10
Power Folding Mirror Relay...............8W-62
Power Mirror Fuse Holder................8W-62
Power Mirrors.........................8W-62
Power Steering Pressure Switch...........8W-30
Power Sunroof Motor....................8W-64
Power Window Motors...................8W-60
Power Window Switches.................8W-60
Powertrain Control Module...............8W-30
PRNDL Lamp.........................8W-44
Radiator Fan Motor.....................8W-42
Radio................................8W-47
Rear Window Defogger..................8W-48
Rear Window Defogger Switch.............8W-48
Remote Keyless Entry Module.............8W-61
Remote Keyless Entry Program
Module Connector....................8W-61
PL8W - 02 COMPONENT INDEX 8W - 02 - 1

COMBINATION FLASHER INPUT L55 20BK/YL
A1
FUNCTION CIRCUIT CAVITYCOMBINATION FLASHER (A) (RHD)
A2L32 20PK COMBINATION FLASHER OUTPUT
GROUND Z2 20BK/LG
A320 18 102
19 17 *16 15 141311
12 (RHD)9 (LHD) 8 (LHD)7
6 5 (RHD)3 1 (LHD)
FUSED CIRCUIT FEED CIRCUIT AMPS FUSE NO.FUSES
G5 20DB/WT
- -- - 10A 15A
15A
L44 20VT/RD L43 20VT 10AX12 18RD/WT 10A 20A F13 18DB
20A F10 18YL/RD-- 5A
F15 18DB/WT 10A 10A F15 18DB/WT
F12 20DG/WT F20 20WT 10AC1 14DG 25A 10A L5 20BK
10A F20 20WT 20A F35 16RD/YLF33 20PK/RD F30 16RD 15A A3 12RD/WT
A3 12RD/WT
A3 12RD/WT
A22 12BK/OR
A22 12BK/OR
A22 12BK/OR
A22 12BK/OR
A21 14DB
A21 14DB
A21 14DB
A31 14BK/WT
A31 14BK/WT
A31 14BK/WT
L4 14VT/WT
L4 14VT/WTG5 20DB/WT ***
F30 18RD
4 **A3 12RD/WT 10A
5 (LHD)10A 1 (RHD)15A A3 12RD/WT
A22 12BK/OR F25 18TN/LG
8 (RHD)10A A22 12BK/OR F25 18TN/LG
9 (RHD)4A E1 20TN E2 20ORA21 14DB
12 (LHD)E1 20TN E2 20OR 4A
L43 20VT
A5 A3M2 20YL
A2
TIME OUT RELAY (A) (LHD)
FUNCTION CIRCUIT CAVITY
M2 20YL
M1 20PK
M23 20YL/BKTIME OUT RELAY OUTPUT
TIME OUT RELAY OUTPUT
FUSED B(+)
TIME OUT RELAY INPUT
- - A3 12RD/WT
4 *F61 20WT/OR
17 **10A L4 14VT/WT L43 18VT
* BUILT-UP-EXPORT
** EXCEPT BUILT-UP-EXPORT -
-
-
*** WITHOUT RKE
PL8W-11 FUSE/FUSE BLOCK 8W - 11 - 5
8211J988W-1

BK/YL20 L7
CIGAR
LIGHTER/
POWER
OUTLET
1
RD16 F30
B2
12
1FUSE15A
21
BATT A3
F30
18
RD
2FUSE15A
22
F33
20
PK/RD
HEADLAMP
SWITCH
4
7C230
L7
20
BK/YL
4
RADIO
12
L7
20
BK/YLL7
20
BK/YL
L7
20
BK/YL
L7
18
BK/YL
2
LAMP STOP
TAIL/
RIGHT
22
LEFT
TAIL/
STOP
LAMP
L7
18
BK/YLL7
20
BK/YL
S306
L7
20
BK/YL
1
9
29
4A
FUSE
9
E1
20
TN
9
2
1 0
FUSE
BLOCK
A
(8W-11-10)TO
C105 C2
SWITCH LAMP
FOG
FRONT
L7
20
BK/YL
B5
RIGHT
LICENSE
LAMP LAMP LICENSE
LEFT (IN FB) RELAY
LIGHTER
CIGAR
2C340C3412
BLOCK
FUSES218
0 OFF
1 PARK
2 HEAD
(8W-41-5)(8W-10-8)
(8W-50-4)
(8W-50-11)
(8W-47-3)
(8W-50-13)(8W-51-8) (8W-51-8) (8W-41-5)
(8W-51-8) (8W-51-8) (8W-11-4)
(8W-11-4)
(8W-11-19)
PL8W-11 FUSE/FUSE BLOCK
RHD BUILT-UP-EXPORT8W - 11 - 9
8215J988W-1

below the minimum acceptable percentage, the PCM
stores a diagnostic trouble code in memory.
During certain idle conditions, the PCM may enter
a variable idle speed strategy. During variable idle
speed strategy the PCM adjusts engine speed based
on the following inputs.
²A/C sense
²Battery voltage
²Battery temperature
²Engine coolant temperature
²Engine run time
²Power steering pressure switch
²Vehicle mileage
ACCELERATION MODE
This is a CLOSED LOOP mode. The PCM recog-
nizes an abrupt increase in Throttle Position sensor
output voltage or MAP sensor output voltage as a
demand for increased engine output and vehicle
acceleration. The PCM increases injector pulse width
in response to increased fuel demand.
DECELERATION MODE
This is a CLOSED LOOP mode. During decelera-
tion the following inputs are received by the PCM:
²A/C pressure transducer
²A/C sense
²Battery voltage
²Intake air temperature
²Engine coolant temperature
²Crankshaft position (engine speed)
²Exhaust gas oxygen content (upstream heated
oxygen sensor)
²Knock sensor
²Manifold absolute pressure
²Power steering pressure switch
²Throttle position
²IAC motor control changes in respones to MAP
sensor feedback
The PCM may receive a closed throttle input from
the Throttle Position Sensor (TPS) when it senses an
abrupt decrease in manifold pressure. This indicates
a hard deceleration. In response, the PCM may
momentarily turn off the injectors. This helps
improve fuel economy, emissions and engine braking.
If decel fuel shutoff is detected, downstream oxy-
gen sensor diagnostics is performed.
WIDE-OPEN-THROTTLE MODE
This is an OPEN LOOP mode. During wide-open-
throttle operation, the following inputs are received
by the PCM:
²Intake air temperature
²Engine coolant temperature
²Engine speed
²Knock sensor
²Manifold absolute pressure²Throttle position
When the PCM senses a wide-open-throttle condi-
tion through the Throttle Position Sensor (TPS) it de-
energizes the A/C compressor clutch relay. This
disables the air conditioning system.
The PCM does not monitor the heated oxygen sen-
sor inputs during wide-open-throttle operation except
for downstream heated oxygen sensor and both
shorted diagnostics. The PCM adjusts injector pulse
width to supply a predetermined amount of addi-
tional fuel.
IGNITION SWITCH OFF MODE
When the operator turns the ignition switch to the
OFF position, the following occurs:
²All outputs are turned off, unless 02 Heater
Monitor test is being run. Refer to Group 25,
On-Board Diagnostics.
²No inputs are monitored except for the heated
oxygen sensors. The PCM monitors the heating ele-
ments in the oxygen sensors and then shuts down.
DESCRIPTION AND OPERATION
SYSTEM DIAGNOSIS
The PCM can test many of its own input and out-
put circuits. If the PCM senses a fault in a major
system, the PCM stores a Diagnostic Trouble Code
(DTC) in memory.
For DTC information, refer to Group 25, Emission
Control Systems. See On-Board Diagnostics.
POWER DISTRIBUTION CENTER
The power distribution center (PDC) is located next
to the battery (Fig. 1). The PDC contains the starter
relay, radiator fan relay, A/C compressor clutch relay,
auto shutdown relay, fuel pump relay and several
fuses.
Fig. 1 Power Distribution Center (PDC)
PLFUEL SYSTEM 14 - 23
GENERAL INFORMATION (Continued)

(3) Open the Power Distribution Center (PDC).
Check for blown fuses. Ensure the relays and fuses
are fully seated in the PDC (Fig. 32). A label on the
underside of the PDC cover shows the locations of
each relay and fuse.
(4) Verify the throttle cable operates freely (Fig.
33).
(5) Check the electrical connections at the idle air
control motor and throttle position sensor (Fig. 34).
(6) Check hose connections between the PCV
valve, vacuum port - intake manifold and the oil sep-
arator (Fig. 35).
(7) Inspect the electrical connections at the MAP
sensor/intake air temperature sensor and the (Fig.
36).
(8) Inspect the fuel injector electrical connections
(Fig. 37).
(9) Inspect the ignition coil electrical connector.
Ensure the spark plug insulators are firmly seated
over the spark plugs (Fig. 38).
Fig. 30 2.0L SOHC Engine Compartment
Fig. 31 Battery, PCM, and PDC
Fig. 32 Power Distribution Center
Fig. 33 Throttle CableÐAutomatic Transmission
Fig. 34 Idle Air Control Motor and Throttle Position
SensorÐTypical
14 - 36 FUEL SYSTEMPL
DIAGNOSIS AND TESTING (Continued)