1995 JEEP YJ check oil

HEATED REAR WINDOW
HEATED REAR WINDOW
The heated rear window relay supplies power to
heated rear window grid. Circuit F83 from fuse 8 in
the fuse 8 in the fuse block supplies power to the
heated rear window relay when the ignition switch is
in the ACCESSORY or RUN positions.
When the operator depresses the heated rear win-
dow switch, the contacts inside the switch momen-
tarily close and circuit C80 connects the switch to the
relay. This causes the relay to change state and com-
plete a circuit to energize the coil side of the relay
and start the relay timer.
Circuit F81 from fuse 18 in the fuse block supplies
voltage to the coil and contact sides of the relay. Cir-
cuit Z1 provides ground for the relay.
When the heated rear window relay energizes, the
contacts inside the relay close and connect circuit
F81 to circuit C15. Circuit C15 splices to the power
the heated rear window grid and the indicator lamp
in the heated rear window switch. Circuit Z1 pro-
vides ground for the heated rear window grid.
HELPFUL INFORMATION
²When the ignition switch is in the ACCESSORY or
RUN positions, it connects circuit A1 from fuse 6 in
the power distribution center (PDC) to circuit A48.
²Check for broken grid lines on the window.
²Check for a broken bus bar or disconnected leads
at the rear window.
²Check for a good ground.
DIAGRAM INDEX
Component Page
Fuse 6 (PDC)...........................8W-48-2
Fuse 7 (PDC)...........................8W-48-2
Fuse 8 (Fuse Block).......................8W-48-2
Fuse 18 (Fuse Block)......................8W-48-2
Ignition Switch..........................8W-48-2
Heated Rear Window Grid...................8W-48-3
Heated Rear Window Relay..................8W-48-2
Heated Rear Window Switch.................8W-48-2
J8W-48 HEATED REAR WINDOWÐXJ VEHICLES 8W - 48 - 1

FRONT LIGHTING
INDEX
page page
Daytime Running Lamp (DRL) Module........... 2
Diagram Index............................ 2
Fog Lamps............................... 1Headlamp Delay Module..................... 2
Headlamps............................... 1
Parking Lamps............................ 1
HEADLAMPS
The headlamp switch has three positions: ON,
PARK (parking lamps) and OFF. Circuit A3 from fuse
5 in the PDC connects to the headlamp switch and
feeds the circuit L7 through fuse 15 in the fuse block.
Circuit L7 connects to the headlamp switch.
Circuit A3 also splices to feed circuit L11 through
fuse 4 in the fuse block. Circuit L11 connects to the
dimmer switch circuitry in the multi-function switch.
Circuit A3 from fuse 5 in the PDC supplies battery
voltage to the headlamp switch. The headlamp switch
has an internal circuit breaker that connects circuit
A3 to circuit F34. Circuit F34 connects to the dimmer
switch circuitry in the multi-function switch.
HEADLAMP SWITCH IN OFF OR PARKING
LAMP POSITION
Circuit L11 connects to the dimmer switch portion
of the multi-function switch. Circuit L11 supplies
power for the high beams on circuit L3 when the
operator flashes the headlamps with the turn signal
stalk of the multi-function switch.
HEADLAMP SWITCH IN ON POSITION
When the headlamp switch is in the ON position,
circuit A3 from fuse 5 in the Power Distribution Cen-
ter (PDC) connects to circuit F34. Circuit F34 con-
nects to the dimmer switch portion of the multi-
function switch and feeds circuit L4. Circuit L4
powers the low beam of the headlamps.
When the operator selects high beam operation
with the turn signal stalk of the multi-function
switch, circuit L11 connects to the L3 circuit. Circuit
L3 powers high beam operation.
HEADLAMP GROUND
Circuit Z1 provides ground for both the right and
left headlamps. Circuit Z1 also supplies ground for
the fog lamps, if equipped.
HELPFUL INFORMATION
²Check fuse 5 in the PDC.
²The headlamp switch has an internal circuit
breaker.
PARKING LAMPS
Circuit A3 from fuse 5 in the Power DistributionCenter (PDC) connects to a bus bar in the fuse block
which feeds circuit L7. Fuse 15 in the fuse block
protects circuit L7.
The headlamp switch has three positions: ON,
PARK (parking lamps) and OFF, plus a dimmer
switch. When the headlamp switch is in the PARK or
ON position, the switch connects circuit L7 to circuit
L90. From the headlamp switch, circuit L90 branches
to power the front parking lamps and rear tail lamps,
side marker lamps, and rear license plate lamps.
GROUND CIRCUIT
Circuit Z1 provides a ground for the parking lamps
and turn signal lamps. The Z1 circuit also provide
ground for the headlamps.
HELPFUL INFORMATION
²Check fuse 5 in the PDC.
²Check fuse 15 in the fuse block.
²When the headlamp switch is in the PARK or ON
position, the dimmer circuit, L7, also connects to cir-
cuit E2. Circuit E2 continues through fuse 19 in the
fuse block. Circuit E2 powers the illumination lamps.
FOG LAMPS
The fog lamps are controlled by the fog lamp
switch, park lamp relay and high beam relay. The fog
lamps operate only when the headlamp switch is in
the ON position, and the operator has selected low-
beam operation. When the headlamps are in high-
beam operation, the fog lamps will not operate.
Circuit F39 from fuse 5 in the Power Distribution
Center (PDC) supplies voltage to the contact side of
the park lamp relay.
Circuit L90 supplies power to the coil side of the
park lamp relay. Circuit L35 connects to the coil side
of the relay and to circuit Z1 through the fog lamp
switch. Ground for the coil side of the relay is pro-
vided on circuit Z1 through the fog lamp switch.
When the fog lamp switch closes, the park lamp
relay contacts close and circuit F39 passes through
the relay to power the contact side of the high beam
relay. When the headlamp high beams are OFF, the
high beam relay is not energized and voltage flows
through the normally closed contacts to circuit L39.
J8W-50 FRONT LIGHTINGÐXJ VEHICLES 8W - 50 - 1

TRAILER TOW
TRAILER TOW
The factory installed trailer tow system in this ve-
hicle uses three relays and a circuit breaker along
with the trailer tow wiring connector located below
the rear bumper.
Battery voltage for the trailer tow circuit breaker
and relays is supplied on circuit A11. This circuit is
HOT at all times and connects to the power accessory
tap in the fuse block. An in line 10 amp circuit pro-
tected breaker protects circuit A11 and the trailer
tow circuits. The trailer tow circuit breaker is located
in the left rear quarter panel.
STOP LAMP RELAY
Power for the coil side of the stop lamp relay is
supplied by circuit L50. This circuit connects to the
stop lamps. Ground for the coil side is supplied on
circuit Z1.
When the operator depresses the brake pedal, volt-
age flows through the coil of the relay to ground
causing the contacts in the relay to connect circuits
A11 and 95.
Circuit 95 connects to the left and right turn signal
relays. Voltage flows through the closed contacts in
the relays to the trailer tow connector.
RIGHT TURN RELAY
Power for the coil side of the right turn relay is
supplied by circuit L60. This circuit connects to the
right side turn signal lamps. Ground for the coil side
of the relay is supplied on circuit Z1.
When the operator turns the right turn signal ON,
power flows through the coil in the relay to ground
causing the contacts in the relay to switch from there
normally CLOSED position to connect circuits 94 and
L60.
Circuit 94 is the feed for the contact side of the re-
lay. Circuit L60 connects from the relay to the trailer
tow connector.
Circuit 94 is fed power through the normally
CLOSED side of the stop lamp relay and circuit A11.
The A11 circuit is HOT at all times and protected by
a 10 amp circuit breaker located in the left rear
quarter panel.
LEFT TURN RELAY
Power for the coil side of the left turn relay is sup-
plied by circuit L61. This circuit connects to the left
side turn signal lamps. Ground for the coil side of the
relay is supplied on circuit Z1.
When the operator turns the left turn signal ON,
power flows through the coil in the relay to ground
causing the contacts in the relay to switch from there
normally CLOSED position to connect circuits 94 and
L61.
Circuit 94 is the feed for the contact side of the re-
lay. Circuit L61 connects from the relay to the trailer
tow connector.
Circuit 94 is fed power through the normally
CLOSED side of the stop lamp relay and circuit A11.
The A11 circuit is HOT at all times and protected by
a 10 amp circuit breaker located in the right rear
quarter panel.
HELPFUL INFORMATION
²Check the In-Line circuit breaker
DIAGRAM INDEX
Component Page
Circuit Breaker (Fuse Block Cavity 16)...........8W-54-4
Circuit Breaker (In-Line)....................8W-54-4
Electric Brake Provision....................8W-54-2
Fuse 3 (PDC)...........................8W-54-4
Left Turn Signal Relay.....................8W-54-3
Left Back-Up Lamp.......................8W-54-2
Left Side Marker Lamp.....................8W-54-2
Left Tail/Stop Lamp.......................8W-54-2
Left Turn Signal Lamp.....................8W-54-2
Right Turn Signal Relay....................8W-54-3
Stop Lamp Relay.........................8W-54-3
Trailer Tow Connector......................8W-54-2
J8W-54 TRAILER TOWÐXJ VEHICLES 8W - 54 - 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

HELPFUL INFORMATION
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.
BRAKE SWITCH INPUT
Circuit K29 provides the brake switch input to the
PCM. Circuit K29 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.
DIAGRAM INDEX
Component Page
Automatic Shut Down Relay.................8W-30-6
Camshaft Position Sensor...................8W-30-8
Crankshaft Position Sensor..................8W-30-9
Data Link Connector......................8W-30-11
Distributor Ignition Coil....................8W-30-11
Engine Coolant Temperature Sensor.............8W-30-9
Fuel Injector #1.........................8W-30-7
Fuel Injector #2.........................8W-30-7
Fuel Injector #3.........................8W-30-7
Fuel Injector #4.........................8W-30-7
Fuel Injector #5.........................8W-30-7
Fuel Injector #6.........................8W-30-7
Fuel Pump Relay........................8W-30-12
Fuel Tank Gauge Level Sending Unit...........8W-30-12
Fuse 2 (PDC)...........................8W-30-6
Fuse 6 (PDC)...........................8W-30-6
Fuse 11 (PDC).......................8W-30-6, 11
Fuse 14 (PDC)..........................8W-30-6
Heated Oxygen Sensor....................8W-30-10
Idle Air Control Motor.....................8W-30-10
Ignition Switch.......................8W-30-6, 12
Instrument Cluster....................8W-30-11, 12
Intake Air Temperature Sensor................8W-30-9
MAP Sensor............................8W-30-8
Powertrain Control Module.............8W-30-6 thru 12
Throttle Position Sensor....................8W-30-8
Vehicle Speed Sensor.....................8W-30-11
J8W-30 FUEL/IGNITIONÐXJ-RHD 8W - 30 - 5

HORN/CIGAR LIGHTER
HORN
The horn system uses two switches and horn relay.
The horn switches are on the steering wheel.
Circuit A7 from fuse 3 in the power distribution
center (PDC) feeds a fuse block bus bar that powers
circuit X4 through fuse 5 in the fuse block. Circuit
X4 is HOT at all times and powers the coil and con-
tact sides of the horn relay.
When the case grounded horn switch is depressed,
circuit X3 provides ground for the coil side of the re-
lay and the contacts close. When the contacts close,
circuit X2 supplies voltage to the case grounded
horns.
HELPFUL INFORMATION
²The horn switches are grounded to the steering
wheel.
²Circuit X4 is double crimped at the coil side of the
horn relay.
²Check fuse 3 in the PDC and fuse 5 in the fuse
block.
CIGAR LIGHTER
In the ACCESSORY or RUN position, the ignition
switch supplies voltage to fuse 13 in the fuse block
on circuit A48. Fuse 13 feeds circuit F85 which con-
nects to the cigar lighter. When the lighter is de-
pressed, the contacts inside of the lighter element
close and voltage flows to ground on circuit Z1.
HELPFUL INFORMATION
²In the ACCESSORY or RUN position, the ignition
switch connects circuit A1 from fuse 6 in the PDC
with circuit A48.
DIAGRAM INDEX
Component Page
Cigar Lighter...........................8W-41-3
Fuse 3 (PDC)...........................8W-41-2
Fuse 6 (PDC)...........................8W-41-3
Fuse 5 (Fuse Block).......................8W-41-2
Fuse 13 (Fuse Block)......................8W-41-3
Horns................................8W-41-2
Horn Relay.............................8W-41-2
Horn Switch............................8W-41-2
Ignition Switch..........................8W-41-3
J8W-41 HORN/CIGAR LIGHTERÐXJ-RHD 8W - 41 - 1

HEATED REAR WINDOW
HEATED REAR WINDOW
The heated rear window relay supplies power to
heated rear window grid. Circuit F83 from fuse 14 in
the fuse block supplies power to the heated rear win-
dow relay when the ignition switch is in the ACCES-
SORY OR RUN positions.
When the operator depresses the heated rear win-
dow switch, the contacts inside the switch momen-
tarily close and circuit C80 connects the switch to the
relay. This causes the relay to change state and com-
plete a circuit to energize the coil side of the relay
and start the relay timer.
Circuit F82 from fuse 7 in the Power Distribution
Center (PDC) supplies voltage to the coil and contact
sides of the relay. Circuit Z1 provides ground for the
relay.
When the heated rear window relay energizes, the
contacts inside the relay close and connect circuit
F82 to circuit C15. Circuit C15 splices to the power
the heated rear window grid and the indicator lamp
in the heated rear window switch. Circuit Z1 pro-
vides ground for the heated rear window grid.
HELPFUL INFORMATION
²When the ignition switch is in the ACCESSORY or
RUN positions, it connects circuit A1 from fuse 11 in
the power distribution center (PDC) to circuit A48.
²Check for broken grid lines on the window.
²Check for a broken bus bar or disconnected leads
at the rear window.
²Check for a good ground.
DIAGRAM INDEX
Component Page
Fuse 2 (Fuse Block).......................8W-48-2
Fuse 6 (PDC)...........................8W-48-2
Fuse 7 (PDC)...........................8W-48-2
Fuse 14 (Fuse Block)......................8W-48-2
Ignition Switch..........................8W-48-2
Heated Rear Window Grid...................8W-48-3
Heated Rear Window Relay..................8W-48-2
Heated Rear Window Switch.................8W-48-2
J8W-48 HEATED REAR WINDOWÐXJ-RHD 8W - 48 - 1

FRONT LIGHTING
INDEX
page page
Diagram Index............................ 3
Dimming Module........................... 1
Fog Lamps............................... 2
Headlamp Delay Module..................... 1Headlamp Relay........................... 1
Headlamps............................... 1
Parking Lamps............................ 2
HEADLAMPS
The headlamp switch has three positions: ON,
PARK (parking lamps) and OFF. Circuit A3 from fuse
12 in the PDC connects to the headlamp switch and
feeds circuit L7 through fuse 9 in the fuse block. Cir-
cuit L7 connects to the headlamp switch.
Circuit A3 also splices to feed circuit L11 through
fuse 10 in the fuse block. Circuit L11 connects to the
dimmer switch circuitry in the multi-function switch.
The headlamp switch has an internal circuit
breaker that connects circuit A3 to circuit F34. Cir-
cuit F34 connects to the headlamp relay.
HEADLAMP RELAY
When the headlamp switch is in the ON position it
connects circuit A3 from fuse 5 in the Power Distri-
bution Center (PDC) to circuit F34. Circuit A3 is
HOT at all times.
Circuit F34 supplies battery voltage to the coil and
contact sides of the headlamp relay. Circuit Z1 sup-
plies ground for the relay. When voltage is present on
circuit F34, the relay contacts close and connect cir-
cuit F39 to circuit F34.
Circuit F39 powers the headlamps through the
dimmer switch circuitry in the multi-function switch.
HEADLAMP SWITCH IN OFF OR PARKING
LAMP POSITION
Circuit L11 connects to the dimmer switch portion
of the multi-function switch. Circuit L11 supplies
power for the high beams on circuit L3 when the op-
erator flashes the headlamps with the turn signal
stalk of the multi-function switch.
HEADLAMP SWITCH IN ON POSITION
When the headlamp switch is in the ON position,
circuit A3 from fuse 12 in the Power Distribution
Center (PDC) connects to circuit F34. Circuit F34
connects to circuit F39 through the headlamp relay.
Circuit F39 feeds circuit L4 through the headlamp
dimmer switch circuitry in the multi-function switch.
Circuit L4 powers the low beam of the headlamps.
When the operator selects high beam operation
with the turn signal stalk of the multi-functionswitch, circuit L11 connects to the L3 circuit. Circuit
L3 powers high beam operation.
HEADLAMP GROUND
Circuit Z1 provides ground for both the right and
left headlamps. Circuit Z1 also supplies ground the
fog lamps, if equipped.
HELPFUL INFORMATION
²Check fuse 5 in the PDC.
²The headlamp switch has an internal circuit
breaker.
²Circuit L7 is double crimped at the headlamp
switch and branches to the chime module.
HEADLAMP DELAY MODULE
When the operator turns off the ignition switch and
the headlamp switch, the headlamp delay module
powers the headlamps for approximately 45 seconds.
When the ignition switch is in the RUN position,
circuit A21 powers circuit F87 through fuse 17 in the
fuse block. Circuit F87 supplies the IGNITION ON/
OFF signal to the headlamp delay module. Circuit Z1
provides ground for the module.
When the headlamp delay module activates, it con-
nects circuit X4 from fuse 5 in the fuse block to cir-
cuit F34. Circuit F34 connects to the circuit F39
through the headlamp relay. Circuit F39 powers the
headlamps through the headlamp dimmer switch cir-
cuit L4.
HELPFUL INFORMATION
Circuit A7 from fuse 3 in the PDC supplies voltage
to the fuse block bus bar that powers circuit X4
through the fuse in cavity 5.
DIMMING MODULE
Some vehicles are equipped with a dimming mod-
ule. The module is powered by the dimming relay.
In the RUN position, the ignition switch connects
circuit A1 from fuse 6 in the Power Distribution Cen-
ter (PDC) to circuit A38. Circuit A38 powers circuit
L170 through fuse 20 in the fuse block. Circuit L170
supplies power to the dimming relay.
When the headlamps are ON, circuit L90 from the
headlamp switch energizes the dimming relay. When
J8W-50 FRONT LIGHTINGÐXJ-RHD 8W - 50 - 1