display JEEP CHEROKEE 1995 Service User Guide

SERVICE PROCEDURES
COMPASS VARIATION ADJUSTMENT
Variance is the difference between magnetic north
and geographic north. In some areas, the difference
between magnetic and geographic north is great
enough to cause the compass to give false readings. If
this occurs, the variance must be set.
To set the variance:
(1) Using the map in Fig. 3, find your geographic
location and note the zone number.
(2) Turn ignition switch to the ON position.
(3) Depress both the US/METRIC and COMP/
TEMP buttons. Hold down until VAR is displayed.
This takes about 5 seconds.
(4) Release both buttons.
(5) Press the US/METRIC button to step through
the numbers until the zone number for your area ap-
pears in the display.
(6) Press the COMP/TEMP button to enter this
zone number into compass unit memory.
(7) Confirm correct directions are indicated.
COMPASS CALIBRATION
CAUTION: DO NOT place any external magnets
such as magnetic roof mount antennas, in the vicin-ity of the compass. DO NOT use magnetic tools
when servicing the overhead console.
The compass features a self-calibrating design,
which simplifies the calibration procedure. This fea-
ture automatically updates the compass calibration
while the vehicle is being driven. This takes into ac-
count small changes in residual magnetism the vehi-
cle may acquire during normal use. Do not attempt
to calibrate the compass near large metal objects
such as other vehicles, large buildings or bridges.
Whenever the compass is calibrated manually,
the variation number must also be reset. See
Variation Adjustment Procedure, in this group.
Calibrate the compass manually as follows:
(1) Start the engine.
(2) Depress both the US/METRIC and COMP/
TEMP buttons. Hold down until CAL is displayed.
This takes about 10 seconds and appears about 5 sec-
onds after VAR is displayed.
(3) Release both buttons.
(4) Drive vehicle on a level surface that is away
from large metal objects through 3 or more complete
circles in not less than 48 seconds. The CAL message
will disappear to indicate that the compass is now
calibrated.
If CAL message remains in display, either
there is excessive magnetism near the compass
or the unit is faulty. Repeat the demagnetizing
and calibration procedures at least one more
time.
If the wrong direction is still indicated, the
area selected may be too close to a strong mag-
netic field. Repeat the calibration procedure in
another location.
COMPASS DEMAGNETIZING
The tool used to degauss or demagnetize the for-
ward console attaching screw and roof panel is the
Miller Tool 6029. Equivalent units must be rated as
continuous duty for 110/115 volts and 60Hz. They
must also have a field strength of over 350 gauss at
1/4-inch beyond the tip of the probe.
The degaussing tool is used to demagnetize both
the roof panel and the console forward mounting
screw, as follows:
(1) Be sure the ignition switch is in the OFF posi-
tion before you begin the demagnetizing procedure.
(2) Plug in the degaussing tool, while keeping the
tool at least 2 feet away from the compass unit.
(3) Slowly approach the head of the forward
mounting screw with the plastic coated tip of the de-
gaussing tool. Contact the head of the screw for
about 2 seconds.Fig. 3 Variance Settings
JOVERHEAD CONSOLE 8C - 5

cap. Fully seat the cables onto the towers. If neces-
sary, refer to the engine Firing Order diagrams (Figs.
8or9).
DISTRIBUTOR ROTOR
Visually inspect the rotor (Fig. 10) for cracks, evi-
dence of corrosion, or the effects of arcing on the
metal tip. Also check for evidence of mechanical in-
terference with the cap. Some charring is normal on
the end of the metal tip. The silicone-dielectric-var-
nish-compound applied to the rotor tip for radio in-
terference noise suppression, will appear charred.
This is normal.Do not remove the charred com-
pound.Test the spring for insufficient tension. Re-
place a rotor that displays any of these adverse
conditions.
DRB SCAN TOOL
For operation of the DRB scan tool, refer to the ap-
propriate Powertrain Diagnostic Procedures service
manual.
Fig. 4 Crankshaft Position SensorÐ4.0L 6-Cyl.
EngineÐYJ models With Auto. Trans.
Fig. 5 Crankshaft Position Sensor Connector
Fig. 6 Cap InspectionÐExternalÐTypical
Fig. 7 Cap InspectionÐInternalÐTypical
Fig. 8 Firing OrderÐ2.5L 4-Cylinder Engine
8D - 8 IGNITION SYSTEMSJ

For diagnostics, refer to the appropriate Powertrain
Diagnostic Procedures service manual for operation
of the DRB scan tool.
SPARK PLUGS
For spark plug removal, cleaning, gap adjustment
and installation, refer to the Component Removal/In-
stallation section of this group.
Faulty carbon and/or gas fouled plugs generally
cause hard starting, but they will clean up at higher
engine speeds. Faulty plugs can be identified in a
number of ways: poor fuel economy, power loss, de-
crease in engine speed, hard starting and, in general,
poor engine performance.
Remove the spark plugs and examine them for
burned electrodes and fouled, cracked or broken por-
celain insulators. For identification, keep plugs ar-
ranged in the order in which they were removed from
the engine. An isolated plug displaying an abnormal
condition indicates that a problem exists in the cor-
responding cylinder. Replace spark plugs at the inter-
vals recommended in the maintenance chart in
Group 0, Lubrication and Maintenance.
Spark plugs that have low mileage may be cleaned
and reused if not otherwise defective. Refer to the
following Spark Plug Condition section of this group.
CONDITION
NORMAL OPERATING
The few deposits present on the spark plug will
probably be light tan or slightly gray in color. This is
evident with most grades of commercial gasoline
(Fig. 19). There will not be evidence of electrode
burning. Gap growth will not average more than ap-
proximately 0.025 mm (.001 in) per 1600 km (1000
miles) of operation. Spark plugs that have normal
wear can usually be cleaned, have the electrodes
filed, have the gap set and then be installed.Some fuel refiners in several areas of the United
States have introduced a manganese additive (MMT)
for unleaded fuel. During combustion, fuel with MMT
causes the entire tip of the spark plug to be coated
with a rust colored deposit. This rust color can be
misdiagnosed as being caused by coolant in the com-
bustion chamber. Spark plug performance is not af-
fected by MMT deposits.
COLD FOULING/CARBON FOULING
Cold fouling is sometimes referred to as carbon
fouling. The deposits that cause cold fouling are ba-
sically carbon (Fig. 19). A dry, black deposit on one or
two plugs in a set may be caused by sticking valves
or defective spark plug cables. Cold (carbon) fouling
of the entire set of spark plugs may be caused by a
clogged air cleaner element or repeated short operat-
ing times (short trips).
WET FOULING OR GAS FOULING
A spark plug coated with excessive wet fuel or oil is
wet fouled. In older engines, worn piston rings, leak-
ing valve guide seals or excessive cylinder wear can
cause wet fouling. In new or recently overhauled en-
gines, wet fouling may occur before break-in (normal
oil control) is achieved. This condition can usually be
resolved by cleaning and reinstalling the fouled
plugs.
OIL OR ASH ENCRUSTED
If one or more spark plugs are oil or oil ash en-
crusted (Fig. 20), evaluate engine condition for the
cause of oil entry into that particular combustion
chamber.
ELECTRODE GAP BRIDGING
Electrode gap bridging may be traced to loose de-
posits in the combustion chamber. These deposits ac-
cumulate on the spark plugs during continuous stop-
and-go driving. When the engine is suddenly
Fig. 18 PCM LocationÐXJ ModelsFig. 19 Normal Operation and Cold (Carbon) Fouling
8D - 12 IGNITION SYSTEMSJ

AUDIO SYSTEMS
CONTENTS
page page
DIAGNOSIS............................. 2
GENERAL INFORMATION.................. 1SERVICE PROCEDURES................... 6
GENERAL INFORMATION
Following are general descriptions of major compo-
nents used in XJ (Cherokee)/YJ (Wrangler) audio sys-
tems. Refer to Group 8W - Wiring Diagrams for
complete circuit descriptions and diagrams.
RADIOS
Radio options for the XJ and YJ models include an
AM/FM stereo or an AM/FM stereo/cassette receiver.
Both units are Electronically-Tuned Radios (ETR)
and include a clock function. For more information
on radio features, setting procedures, and control
functions refer to the owner's manual.
IN-LINE FUSE
Each radio receives fused battery feed when the ig-
nition switch is in the ON or ACCESSORY position.
There is an additional in-line fuse in the back of the
radio chassis. The in-line fuse (Fig. 1) will blow to
protect the vehicle electrical system in the event of
internal radio failure.
IGNITION-OFF DRAW FUSE
All vehicles are equipped with an Ignition-Off
Draw (IOD) fuse that is removed when the vehicle is
shipped from the factory. This fuse feeds various ac-
cessories that require current when the ignition
switch is in the OFF position, including the clock and
radio station preset memory functions. The fuse is re-
moved to prevent battery discharge during vehicle
storage.The IOD fuse should be checked if the radio station
preset memory or clock functions are erratic or inop-
erative. The IOD fuse is located in the Power Distri-
bution Center (PDC). Refer to underside of PDC
cover for IOD fuse identification.
RADIO ILLUMINATION RELAY
All radios are connected to a radio illumination re-
lay. The relay controls the source of battery feed for
radio/clock display illumination.
When the park and headlamp switch is in the OFF
position, the radio illumination relay remains de-en-
ergized. The radio/clock display receives full battery
voltage through the normally closed contacts of the
relay. This results in the radio/clock display being il-
luminated at full brightness for easier visibility in
daylight.
When the park and headlamp switch is in the ON
position, the radio illumination relay coil is ener-
gized. With the relay coil energized, the normally
closed contacts of the relay open, and the normally
open contacts of the relay close. This causes the ra-
dio/clock display to receive battery feed through the
instrument panel dimmer switch. The display illumi-
nation brightness can now be adjusted with other
panel lamps for night visibility.
SPEAKERS
Speaker system options include two, four or six (XJ
only) speaker locations. On XJ model two-speaker
systems, one speaker is located in each front door.
Four-speaker systems add one speaker at each end of
a rear-mounted overhead sound bar. The premium
six-speaker option upgrades all the speakers in the
above locations, and adds one tweeter at each end of
the lower instrument panel.
On YJ model two-speaker systems, one speaker is
located at each end of the instrument panel. Four-
speaker systems add one speaker at each end of a
rear-mounted overhead sound bar.
Fig. 1 In-Line Fuse
JAUDIO SYSTEMS 8F - 1

RADIO ILLUMINATION RELAY
If the relay fails any one of Relay Tests, it is faulty
and should be replaced. If the relay passes the Relay
Tests, proceed to the Relay Circuit Tests.
On XJ models, the radio illumination relay is lo-
cated in the relay center (Fig. 2), which is fastened to
the lower instrument panel reinforcement behind the
lower instrument panel near the steering column. On
YJ models, the relay is taped to the instrument panel
wiring harness above and to the right of the radio,
near the glove box.
RELAY TESTS
Remove relay to perform the following tests:
(1) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
no continuity between terminals 87 and 30.(2) Resistance value between terminals 85 and 86
(electromagnet) is 7565 ohms.
(3) Connect a battery to terminals 85 and 86. There
should now be continuity between terminals 30 and 87,
and no continuity between terminals 87A and 30.
RELAY CIRCUIT TESTS
With relay still removed, perform the following
tests:
(1) The common feed terminal (30) is connected to
the radio display feed circuit. There should be conti-
nuity between cavity for relay terminal 30 and clock/
radio display feed cavity of radio connector at all
times. If not, repair circuit as required.
(2) The normally closed terminal (87A) is connected
to terminal 30 in the de-energized position. This circuit
provides ignition-switched battery voltage to the radio
display when the headlamp switch is off. There should
be battery voltage present at cavity for relay terminal
87A with the ignition switch in the ON position. If not,
repair circuit to ignition switch as required.
(3) The normally open terminal (87) is connected to
terminal 30 in the energized position. This circuit
provides instrument panel dimmer controlled feed to
the radio display when the headlamp switch is on.
There should be voltage present at cavity for relay
terminal 87 when the headlamp switch is on. Also,
the voltage reading should vary as the panel dimmer
switch is rotated. If not, repair circuit or panel dim-
mer switch as required.
(4) The coil battery terminal (86) connected to the
electromagnet in the relay. Check as follows:
(a) On YJ models, it is energized when the head-
lamp switch is on. There should be battery voltage at
cavity for relay terminal 86 with the headlamp switch
on. If not, repair circuit to headlamp switch as re-
quired.
(b) On XJ models, it is grounded at all times.
There should be continuity to ground at cavity for
relay terminal 86 at all times. If not, repair circuit
to ground as required.
RADIO CONNECTIONS
Fig. 2 Radio Illumination Relay - XJ
RADIO ILLUMINATION RELAY CONNECTIONS
8F - 4 AUDIO SYSTEMSJ

USING ON-BOARD DIAGNOSTIC SYSTEM
The Powertrain Control Module (PCM) monitors
critical input and output circuits of the speed control
system, making sure they are operational. A Diagnos-
tic Trouble Code (DTC) is assigned to each input and
output circuit monitored by the OBD system. Some
circuits are checked continuously and some are
checked only under certain conditions.
If the OBD system senses that a monitored circuit
is bad, it will put a DTC into electronic memory. The
DTC will stay in electronic memory as long as the
circuit continues to be bad. The PCM is programmed
to clear the memory after 50 engine starts, if the
problem does not occur again.
DIAGNOSTIC TROUBLE CODES
Diagnostic Trouble Codes (DTC) are two-digit num-
bers flashed on the malfunction indicator (Check En-
gine) lamp that identify which circuit is bad. A DTC
description can also be read using the DRB scan tool.
Refer to Group 14 - Fuel Systems for more informa-
tion.
A DTC does not identify which component in a cir-
cuit is bad. Thus, a DTC should be treated as a
symptom, not as the cause for the problem. In some
cases, because of the design of the diagnostic test
procedure, a DTC can be the reason for another DTC
to be set. Therefore, it is important that the test pro-
cedures be followed in sequence, to understand what
caused a DTC to be set.
See Speed Control Diagnostic Trouble Code chart
for DTC's which apply to the speed control system.Refer to the Powertrain Diagnostic Procedures man-
ual to diagnose an on-board diagnostic system trou-
ble code.
RETRIEVING DIAGNOSTIC TROUBLE CODES
To start this function, cycle the ignition switch ON-
OFF-ON-OFF-ON within 5 seconds. This will cause
any DTC stored in the PCM memory to be displayed.
The malfunction indicator (Check Engine) lamp will
display a DTC by flashing on and off. There is a
short pause between flashes and a longer pause be-
tween digits. All DTC's displayed are two-digit num-
bers, with a four-second pause between codes.
An example of a DTC is as follows:
(1) Lamp on for 2 seconds, then turns off.
(2) Lamp flashes 1 time pauses and then flashes 5
times.
(3) Lamp pauses for 4 seconds, flashes 3 times,
pauses, then flashes 4 times.
The two DTC's are 15 and 34. Any number of
DTC's can be displayed, as long as they are in mem-
ory. The lamp will flash until all stored DTC's are
displayed (55 = end of test).
If a DTC 15 is observed, see diagnosis for Vehicle
Speed Sensor in this group. If a DTC 34 is observed,
see diagnosis for Speed Control Servo and Power-
train Control Module in this group. Correct any prob-
lems found in your diagnosis, then recheck for DTC
after corrections are completed.
VEHICLE SPEED SENSOR
For diagnosis of the VSS, refer to the appropriate
Powertrain Diagnostic Procedures manual.
SPEED CONTROL DIAGNOSTIC TROUBLE CODE
JVEHICLE SPEED CONTROL SYSTEM 8H - 5

Circuit T17 from fuse 3 in the power distribution
center supplies voltage to the coil and contact sides
of the TCC relay. When the PCM provides a ground
path on circuit K54 for the coil side of the relay, the
relay contacts close.
When the relay contacts close, they connect circuit
T17 with circuit T22. Circuit T22 supplies battery
voltage to the case grounded TCC solenoid. Circuit
K54 connects to PCM cavity 54.
HELPFUL INFORMATION
²In the RUN or START position, the ignition switch
connects circuit A1 from fuse 4 in the PDC to circuit
A21.
UPSHIFT LAMP
On vehicles equipped with a manual transmission,
the PCM grounds the up-shift lamp on circuit K54.
Circuit K54 connects to cavity 54 of the PCM.
POWER STEERING PRESSURE SWITCH
The PCM supplies voltage to the power steering
pressure switch on circuit K10. Circuit Z12 provides
ground for the switch. When the switch closes, volt-
age flows through the switch to ground on circuit
Z12. The switch closes during periods of high power
steering pump load and low engine speed; such as
parking maneuvers.
Circuit K10 connects to cavity 10 of the PCM. Cir-
cuit Z12 terminates at the right rear of the engine.
TACHOMETER SIGNAL
The PCM supplies the signal for the tachometer on
circuit G21. Circuit G21 connects to cavity 43 of the
PCM.
MALFUNCTION INDICATOR LAMP (MIL)
The PCM provides ground for the instrument clus-
ter malfunction indicator lamp on circuit G3. The
MIL displays the message CHECK ENGINE when il-
luminated. Circuit F87 provides voltage for the lamp.
DATA LINK CONNECTOR
Circuit F12 supplies battery voltage to the data
link connector. Circuit F12 originates at fuse 11 in
the Power Distribution Center.
Circuit D20 connects to cavity 45 of the PCM. Cir-
cuit D20 is the SCI receive circuit for the PCM.
Circuit D21 connects to cavity 25 of the PCM. Cir-
cuit D21 is the SCI transmit circuit for the PCM.
Circuit Z11 provides ground for the data link con-
nector. Circuit Z11 terminates at the right rear of the
engine. Circuit Z11 also connects to cavity 5 of the
PCM.
HELPFUL INFORMATION
²Circuit Z1 also supplies a ground for the PCM
high current drivers.
²If the system loses ground for the Z11 circuits at
the right rear of the engine, the vehicle will not op-
erate. Check the connection at the ganged-ground cir-
cuit eyelet.
²Circuit F12 splices to supply battery voltage to the
vehicle speed control switch, back-up lamp switch,
A/C compressor clutch relay, windshield washer fluid
level sensor and radiator fan relay (4.0L engines).
BRAKE SWITCH INPUT
Circuit K29 provides the brake switch input to the
PCM. Circuit V40 connects to cavity 29 of the PCM.
POWER (DEVICE) GROUND
Circuit Z12 connects to cavities 11 and 12 of the
PCM. The Z12 circuit provides ground for PCM inter-
nal drivers that operate high current devices like the
injectors and ignition coil.
Internal to the PCM, the power (device) ground cir-
cuit connects to the PCM sensor return circuit (from
circuit K4).
HELPFUL INFORMATION
²The grounding point for circuit Z12 is the right
rear of the engine.
²If the system loses ground for the Z12 circuits at
the rear of the engine, the vehicle will not operate.
Check the connection at the ganged-ground circuit
eyelet.
²On vehicles equipped with the 4.0L engine and au-
tomatic transmission, circuit Z12 splices to provide
ground for the transmission control module.
EXTENDED IDLE SWITCH
On Police Package vehicles, an optional extended
idle switch provides an input to the Powertrain Con-
trol Module (PCM) on circuit K10. Circuit K10 con-
nects to cavity 10 of the PCM. Circuit F60 supplies
battery voltage to the extended idle switch. Circuit
Z1 grounds the switch.
CCD BUS
On vehicles equipped with the 4.0L engine, circuits
D1 and D2 connect the Powertrain Control Module
(PCM) to the CCD Bus. Circuit D1 connects to cavity
26 of the PCM. Circuit D2 connects to cavity 46 of
the PCM. Circuits D1 and D2 are a twisted pair of
wires.
J8W-30 FUEL/IGNITIONÐXJ VEHICLES 8W - 30 - 5

OIL PRESSURE GAUGE
The case grounded oil pressure sensor is a variable
resistor that connects to circuit G6. Circuit G6 con-
nects to the oil pressure gauge.
Circuit F87 connects to the instrument cluster con-
nector and supplies battery voltage to oil pressure
gauge. The gauge uses two coils. Current passing
through the coils creates a magnetic field. Position of
the gauge needle is controlled by the amount of cur-
rent passing through the coils to ground at the sen-
sor.
OIL PRESSURE WARNING LAMP
The case grounded oil pressure switch connects to
circuit G6. Circuit G6 connects to the oil pressure
warning lamp. Circuit F87 connects to the instru-
ment cluster connector and supplies battery voltage
to oil pressure lamp.
When the oil pressure switch close, battery voltage
flows through the warning lamp to ground through
the switch, illuminating the lamp.
TACHOMETER
The tachometer module in the instrument cluster
operates the tachometer. The Powertrain Control
Module (PCM) supplies the signal for the tachometer
on circuit G21. Circuit G21 connects to cavity 43 of
the PCM.
SPEEDOMETER
The speedometer and odometer receive a signal
from the vehicle speed sensor on circuit G7. Circuit
G7 also connects to the Powertrain Control Module
(PCM) at cavity 47.
ABS WARNING LAMP
Circuit F87 provides power for the ABS warning
lamp at the instrument cluster. Ground for the ABS
warning lamp is provided by either the ABS control
module or by the ABS power relay when the relay is
not energized. The ABS control module illuminates
the lamp by providing ground on circuit B205.
Circuit B205 splices to connect to circuit B235
through a diode. When the ABS power relay is not
energized, it connects circuit B235 to circuit Z12. The
ground path for the warning lamp is through the di-
ode to circuit B235, through the ABS power relay to
ground on circuit Z12.
The diode between circuit B205 and B235 prevents
voltage from flowing to the ABS control module when
the ABS power relay switches to supply power on cir-
cuit B235.
MALFUNCTION INDICATOR LAMP (MIL)
The PCM provides ground for the instrument clus-
ter malfunction indicator lamp on circuit G3. Circuit
G3 connects to cavity 32 of the PCM. Circuit F87provides voltage for the lamp. The MIL displays the
message CHECK ENGINE when illuminated.
For information regarding diagnostic trouble code
access using the MIL lamp, refer to Group 14, Fuel
Systems.
LOW WASHER FLUID WARNING LAMP
Circuit G29 connects the low washer fluid switch to
the warning lamp in the instrument cluster. Circuit
F12 supplies battery voltage to the switch.
When the low washer fluid switch closes, it con-
nects circuits G29 and F12. Battery voltage from cir-
cuit F12 powers the low washer fluid lamp. Circuit
Z1 at the instrument cluster provides ground to illu-
minate the warning lamp.
SEAT BELT INDICATOR WARNING LAMP
The seat belt indicator warning lamp is activated
by the chime/buzzer on circuit G11. Circuit G11 sup-
plies power to instrument cluster for the lamp. Cir-
cuit Z1 provides ground for the lamp at the cluster.
The chime/buzzer module powers circuit G11 after
it receives an input on circuit G10 indicating the seat
belt switch is open.
HIGH-BEAM INDICATOR LAMP
Circuit L3 supplies power for the high-beam indi-
cator lamp. The ground path for the lamp is through
circuit Z1. If the vehicle has Daytime Running
Lamps (DRL), the DRL module powers circuit L3
through circuit G465. On vehicles not equipped with
DRL, the headlamp switch powers circuit L3.
Circuit Z1 provides ground for the indicator lamp
at the cluster.
TURN SIGNAL INDICATOR LAMPS
Circuits L61 and L60 power for the turn signal in-
dicator lamps. Circuit L61 powers the left indicator
lamp. Circuit L60 powers the right indicator lamp.
Circuit Z1 provides ground for the lamps.
BRAKE WARNING LAMP
Circuit F87 supplies power to the park brake lamp.
Ground for the park brake lamp is supplied through
the case grounded park brake switch or brake warn-
ing switch on circuit G9. Circuit G9 Connects to cir-
cuit B203. Circuit B203 connects to the brake
warning lamp at the instrument cluster.
MANUAL TRANSMISSION UP-SHIFT LAMP
Circuit F87 supplies power for the manual trans-
mission up-shift lamp. The lamp illuminates when
the Powertrain Control Module (PCM) provides
ground for the lamp on circuit K54. Circuit K54 con-
nects to cavity 54 of the PCM.
8W - 40 - 2 8W-40 INSTRUMENT CLUSTERÐXJ VEHICLESJ

AUDIO SYSTEM
RADIO
When the ignition switch is in the ACCESSORY or
RUN position, it connects circuit A1 from fuse 6 in the
Power Distribution Center (PDC) to circuit A48. Cir-
cuit A48 powers circuit F85 through fuse 2 in the fuse
block. Circuit F85 powers the radio.
Circuit Z1 provides ground for the radio. The an-
tenna connects to the rear of the radio.
RADIO MEMORY
Circuit M1 from the Ignition Off Draw (IOD) fuse
(fuse 9) in the fuse block supplies power for the radio
memory. The IOD fuse is removed during vehicle
shipping to prevent excessive battery draw.
Circuit A6 from fuse 16 in the Power Distribution
Center (PDC) supplies voltage to fuse 9. Circuit A7
from fuse 3 in the PDC powers circuit A6 through
fuse 16. Circuits A6, A7 and M1 are HOT at all times.
RADIO ILLUMINATION
Circuit E2 supplies battery voltage to the radio
illumination lamps when the headlamps or parking
lamps are on and the dimmer switch is in the LOW or
ON positions.
Circuit X5 supplies battery voltage for the radio
clock and station frequency display. Circuit X5 origi-
nates at the radio illumination relay and is fed by
either circuit F85 or circuit E2 depending on the
switch position inside the relay.
When the headlamps and parking lamps are off, the
radio illumination relay is in its normal At Rest posi-
tion. In the At Rest position, the relay connects circuit
F85 from fuse 2 in the fuse block to circuit X5.
When the headlamps or parking lamps are on, cir-
cuit L90 from the headlamp switch supplies battery
voltage to the coil side of the radio illumination relay.
Circuit Z1 provides ground for the coil side of the
relay.
When voltage is present on circuit L90, the radio
illumination relay switches from its At Rest position
to connect circuit E2 to circuit X5.
SPEAKERS
There are 3 different radio packages. The standard
radio package includes 2 speakers; one in each front
door. The four speaker system uses speakers in each
front door plus speakers in the rear sound bar. The six
speaker system has the front door speakers, sound bar
speakers and two speakers in the instrument panel.
BASE RADIO
Vehicles with the base radio have a jumper between
the radio and the instrument panel connectors. The
jumper simulates rear speaker load.Circuit X53 feeds the speaker in the left front door.
Circuit X55 is the return from the speaker to the
radio.
Circuit X54 feeds the right front door speaker. Cir-
cuit X56 is the return from the speaker to the radio.
FOUR SPEAKER SYSTEM
Circuit X53 feeds the speaker in the left front door.
Circuit X55 is the return from the speaker to the
radio.
Circuit X54 feeds the right front door speaker. Cir-
cuit X56 is the return from the speaker to the radio.
Circuit X51 feeds the left rear speaker. Circuit X57
is the return from the speaker to the radio.
Circuit X52 feeds the right rear speaker. Circuit
X58 is the return from the speaker to the radio.
SIX SPEAKER SYSTEM
Circuit X53 feeds the left speaker in the instrument
panel. The X53 circuit is double crimped at the in-
strument panel left speaker and branches to the left
front door speaker. Circuit X55 is the return to the
radio from the instrument panel left speaker and left
front door speaker. Circuit X55 is double crimped at
the instrument panel left speaker.
Circuit X54 feeds the right speaker in the instru-
ment panel. The X54 circuit is double crimped at the
instrument panel right speaker and branches to the
right front door speaker. Circuit X56 is the return to
the radio from the instrument panel left speaker and
left front door speaker. Circuit X56 is double crimped
at the instrument panel left speaker.
Circuit X51 feeds the left rear speaker. Circuit X57
is the return from the speaker to the radio.
Circuit X52 feeds the right rear speaker. Circuit
X58 is the return from the speaker to the radio.
DIAGRAM INDEX
Component Page
Fuse Block...........................8W-47-2, 3
Headlamp Switch.........................8W-47-2
Ignition Switch..........................8W-47-2
LCD Relay.............................8W-47-3
Power Distribution Center..................8W-47-2, 3
Radio............................8W-47-2 thru 7
Speakers (Six Speaker System)..............8W-47-4, 5
Speakers (Four Speaker System).............8W-47-6, 7
J8W-47 AUDIO SYSTEMÐXJ VEHICLES 8W -47 - 1

THROTTLE POSITION SENSOR
From the Powertrain Control Module (PCM), cir-
cuit K6 supplies 5 volts to the throttle position sen-
sor (TPS). Circuit K6 connects to cavity 6 of the
PCM.
Circuit K22 delivers the TPS signal to the PCM.
Circuit K22 connects to cavity 22 of the PCM.
The PCM provides a ground for the throttle posi-
tion sensor signal (circuit K22) through circuit K4.
Circuit K4 connects to cavity 4 of the PCM.
HELPFUL INFORMATION
Refer to Group 14 for throttle position sensor oper-
ation.
Circuit K6 splices to supply 5 volts to the manifold
absolute pressure sensor.
Circuit K22 splices to the transmission control
module.
Circuit K4 splices to supply ground for the signals
from the following:
²Heated oxygen sensor
²Camshaft position sensor
²Crankshaft position sensor
²Intake air temperature sensor
²Manifold absolute pressure sensor
²Engine coolant temperature sensor
²Vehicle speed sensor
MANIFOLD ABSOLUTE PRESSURE SENSOR
From the Powertrain Control Module (PCM), cir-
cuit K6 supplies 5 volts to the manifold absolute
pressure (MAP) sensor. Circuit K6 connects to cavity
6 of the PCM.
Circuit K1 delivers the MAP signal to the PCM.
Circuit K1 connects to cavity 1 of the PCM.
The PCM provides a ground for the MAP sensor
signal (circuit K1) through circuit K4. Circuit K4 con-
nects to cavity 4 of the PCM.
HELPFUL INFORMATION
Refer to Group 14 for MAP sensor operation.
Circuit K6 splices to supply 5 volts to the throttle
position sensor.
Circuit K4 splices to supply ground for the signals
from the following:
²Heated oxygen sensor
²Camshaft position sensor
²Crankshaft position sensor
²Intake air temperature sensor
²Throttle position sensor
²Engine coolant temperature sensor
²Vehicle speed sensor
INTAKE AIR TEMPERATURE SENSOR
The intake air temperature sensor provides an in-
put to the Powertrain Control Module (PCM) on cir-
cuit K21. Circuit K21 connects to cavity 21 of the
PCM.From circuit K21, the intake air temperature sen-
sor draws voltage from the PCM. The sensor is a
variable resistor. As intake air temperature changes,
the resistance in the sensor changes, causing a
change in current draw.
The PCM provides a ground for the intake air tem-
perature sensor signal (circuit K21) through circuit
K4. Circuit K4 connects to cavity 4 of the PCM.
HELPFUL INFORMATION
Circuit K4 splices to supply ground for the signals
from the following:
²Heated oxygen sensor
²Camshaft position sensor
²Crankshaft position sensor
²Throttle position sensor
²Manifold absolute pressure sensor
²Engine coolant temperature sensor
²Vehicle speed sensor
PARK/NEUTRAL POSITION SWITCH
When closed, the case-grounded park/neutral posi-
tion switch provides a ground path on circuit T41 for
the coil side of the starter motor relay. Circuit A41
from the ignition switch provides battery voltage to
the coil side of the relay.
Circuit T41 splices to cavity 30 of the PCM. The
park/neutral position switch provides an input to the
Powertrain Control Module (PCM).
TACHOMETER SIGNAL
The PCM supplies the signal for the tachometer on
circuit G21. Circuit G21 connects to cavity 43 of the
PCM.
MALFUNCTION INDICATOR LAMP (MIL)
The Powertrain Control Module (PCM) provides
ground for the instrument cluster malfunction indica-
tor lamp on circuit G3. The MIL displays the mes-
sage CHECK ENGINE when illuminated. Circuit
F87 provides voltage for the lamp. Circuit G3 con-
nects to cavity 32 of the PCM.
DATA LINK CONNECTOR
Circuit F12 supplies battery voltage to the data
link connector. Circuit F12 originates at fuse 11 in
the Power Distribution Center.
Circuit D20 connects to cavity 45 of the PCM. Cir-
cuit D20 is the SCI receive circuit for the PCM.
Circuit D21 connects to cavity 25 of the PCM. Cir-
cuit D21 is the SCI transmit circuit for the PCM.
Circuit Z11 provides ground for the data link con-
nector. Circuit Z11 also connects to cavity 5 of the
PCM.
8W - 30 - 4 8W-30 FUEL/IGNITIONÐXJ-RHDJ