1995 JEEP YJ oil temperature

FUEL/IGNITION
INDEX
page page
Automatic Shut Down (ASD) Relay............. 1
Battery Feed.............................. 1
Brake Switch Input......................... 5
Camshaft Position Sensor.................... 3
CCDBus ................................ 5
Crankshaft Position Sensor................... 3
Data Link Connector........................ 5
Diagram Index Ð2.5L Engine.................. 6
Diagram Index Ð4.0L Engine.................. 6
Engine Coolant Temperature Sensor............ 3
Extended Idle Switch....................... 5
Fuel Injectors............................. 1
Fuel Pump Module......................... 2
Fuel Pump Relay.......................... 2
Heated Oxygen Sensor...................... 3Idle Air Control (IAC) Motor................... 2
Ignition Coil.............................. 2
Ignition Switch............................ 1
Intake Air Temperature Sensor................ 4
Malfunction Indicator Lamp (MIL)............... 5
Manifold Absolute Pressure Sensor............. 4
Park/Neutral Position Switch.................. 4
Power (Device) Ground...................... 5
Power Steering Pressure Switch............... 5
Tachometer Signal......................... 5
Throttle Position Sensor..................... 4
Torque Converter Clutch (TCC) Solenoid and
Relay................................. 4
Upshift Lamp............................. 5
Vehicle Speed Sensor....................... 2
IGNITION SWITCH
Circuit A1 from fuse 11 in the power distribution
center (PDC), supplies battery voltage to the ignition
switch. Depending upon position, the ignition switch
powers circuits A21, A38, A41, or A48.
START POSITION
In the START position, the ignition switch connects
circuit A1 to circuit A41. Circuit A41 connects to the
coil side of the starter motor relay.
Additionally in the START position, the case
grounded ignition switch provides ground for the
brake lamp switch and the warning lamps in the
instrument cluster.
START OR RUN POSITION
In the START or RUN position, the ignition switch
connects circuit A1 to circuit A21. Circuit A21 splices
to power fuse 17 in the fuse block and the coil side of
the Automatic Shut Down (ASD) relay and the fuel
pump relay.
RUN (ONLY) POSITION
When the ignition switch is in the RUN position, it
connects circuit A1 to circuit A38. Circuit A22 splices
to power fuses 1 and 7 in the fuse block.
²Fuse 1 powers the rear wiper system on circuit
V15.
²Fuse 7 feeds the Anti-Lock Brake System (ABS) on
circuit 236.
ACCESSORY OR RUN POSITIONS
In the ACCESSORY or RUN positions, the ignition
switch connects circuit A1 to circuit A48. Circuit A48
connects to a bus bar in the fuse block that feeds
fuses 2, 5, and 8.
AUTOMATIC SHUT DOWN (ASD) RELAY
When the ignition switch is in either the START or
RUN positions, it connects circuit A1 from fuse 6 in
the Power Distribution Center (PDC) to circuit A21.
Circuit A21 supplies battery voltage to the coil side of
the Automatic Shut Down (ASD) relay. The Power-
train Control Module (PCM) provides ground for the
relay on circuit K51. Circuit K51 connects to cavity 51
of the PCM.
When the PCM grounds the ASD relay, contacts
inside the relay close and connect circuit A18 from
fuse 14 in the PDC to circuit A142. Circuit A142
splices to the generator field terminal, fuel injectors,
and ignition coil. Circuit A142 also connects to cavity
57 of the PCM.
HELPFUL INFORMATION
²Along with supplying voltage to the coil side of the
ASD relay, circuit A21 also supplies voltage to the coil
side of the fuel pump relay.
BATTERY FEED
Circuit A14 from fuse 2 in the Power Distribution
Center (PDC) supplies battery voltage to cavity 3 of
the powertrain control module.
HELPFUL INFORMATION
Circuit A14 also supplies power to the contact sides
of the fuel pump relay and fuse F2 in the PDC. Fuse
F2 powers circuit A18 which supplies voltage to the
contact side of the automatic shut down relay.
FUEL INJECTORS
When the Automatic Shut Down (ASD) relay con-
tacts close, they connect circuits A14 and A142. Cir-
J8W-30 FUEL/IGNITIONÐXJ VEHICLES 8W - 30 - 1

The PCM provides a ground for the engine coolant
temperature sensor signal (circuit K2) through circuit
K4. Circuit K4 connects to cavity 4 of the PCM con-
nector.
HELPFUL INFORMATION
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
²Manifold absolute pressure sensor
²Engine coolant temperature sensor
²Vehicle speed sensor
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.
On vehicles equipped with the 4.0L engine and au-
tomatic transmission, 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
²Throttle position 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
²Manifold absolute pressure 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
²Intake air temperature 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).
TORQUE CONVERTER CLUTCH (TCC) SOLENOID
AND RELAY
The TCC solenoid is only used on 2.5L engines
with the three-speed automatic transmissions. The
Powertrain Control Module (PCM) operates the TCC
solenoid by energizing the TCC relay.
8W - 30 - 4 8W-30 FUEL/IGNITIONÐXJ VEHICLESJ

DIAGRAM INDEXÐ2.5L ENGINE
Component Page
Automatic Shut Down Relay.................8W-30-8
Camshaft Position Sensor..................8W-30-10
Crankshaft Position Sensor.................8W-30-11
Data Link Connector......................8W-30-12
Distributor Ignition Coil....................8W-30-12
Engine Coolant Temperature Sensor............8W-30-11
Fuel Injector #1.........................8W-30-9
Fuel Injector #2.........................8W-30-9
Fuel Injector #3.........................8W-30-9
Fuel Injector #4.........................8W-30-9
Fuel Pump Relay........................8W-30-20
Fuel Tank Gauge Level Sending Unit...........8W-30-20
Fuse 2 (PDC)........................8W-30-8, 20
Fuse 6 (PDC)........................8W-30-8, 20
Fuse 11 (PDC).........................8W-30-12
Fuse 14 (PDC)..........................8W-30-8
Heated Oxygen Sensor.....................8W-30-7
Idle Air Control Motor.....................8W-30-7
Ignition Switch.......................8W-30-8, 20
Instrument Cluster....................8W-30-12, 20
Intake Air Temperature Sensor...............8W-30-11
MAP Sensor...........................8W-30-10
Powertrain Control Module........8W-30-7 thru 12, 19, 20
Power Steering Pressure Switch...............8W-30-7
Throttle Position Sensor...................8W-30-10
Vehicle Speed Sensor.....................8W-30-12
DIAGRAM INDEXÐ4.0L ENGINE
Component Page
Automatic Shut Down Relay.................8W-30-14
Camshaft Position Sensor..................8W-30-16
Crankshaft Position Sensor.................8W-30-16
Data Link Connector......................8W-30-18
Distributor Ignition Coil....................8W-30-18
Engine Coolant Temperature Sensor............8W-30-17
Extended Idle Switch.....................8W-30-19
Extended Idle Switch Lamp.................8W-30-19
Fuel Injector #1.........................8W-30-15
Fuel Injector #2.........................8W-30-15
Fuel Injector #3.........................8W-30-15
Fuel Injector #4.........................8W-30-15
Fuel Injector #5.........................8W-30-15
Fuel Injector #6.........................8W-30-15
Fuel Pump Relay........................8W-30-20
Fuel Tank Gauge Level Sending Unit...........8W-30-20
Fuse 2 (PDC).......................8W-30-14, 20
Fuse 3 (Fuse Block)......................8W-30-19
Fuse 5 (PDC)..........................8W-30-19
Fuse 6 (PDC).....................8W-30-14, 19, 20
Fuse 14 (PDC).........................8W-30-14
Fuse 15 (Fuse Block).....................8W-30-19
Fuse 19 (Fuse Block).....................8W-30-19
Headlamp Switch........................8W-30-19
Heated Oxygen Sensor....................8W-30-13
Idle Air Control Motor.....................8W-30-13
Ignition Switch....................8W-30-14, 19, 20
Instrument Cluster.......................8W-30-18
Intake Air Temperature Sensor...............8W-30-17
MAP Sensor...........................8W-30-16
Powertrain Control Module............8W-30-13 thru 20
Throttle Position Sensor...................8W-30-16
Vehicle Speed Sensor.....................8W-30-18
8W - 30 - 6 8W-30 FUEL/IGNITIONÐXJ VEHICLESJ

INSTRUMENT CLUSTER
INDEX
page page
ABS Warning Lamp........................ 2
Brake Warning Lamp....................... 2
Charging System Indicator Lamp............... 3
Cluster Ground............................ 3
Diagram Index............................. 3
Engine Coolant Temperature Gauge............ 1
Engine Coolant Temperature Warning Lamp...... 1
Fuel Gauge.............................. 1
High-Beam Indicator Lamp................... 2
Instrument Cluster......................... 1Low Fuel Warning Lamp..................... 1
Low Washer Fluid Warning Lamp.............. 2
Malfunction Indicator Lamp (MIL)............... 2
Manual Transmission Up-Shift Lamp............ 2
Oil Pressure Gauge........................ 2
Oil Pressure Warning Lamp.................. 2
Seat Belt Indicator Warning Lamp.............. 2
Speedometer............................. 2
Tachometer.............................. 2
Turn Signal Indicator Lamps.................. 2
INSTRUMENT CLUSTER
The instrument cluster contains the gauges and
warning lamps. All gauges have magnetic move-
ments.
When the ignition switch is in the START or RUN
position, circuit A21 feeds circuit F87 through fuse 17
in the fuse block. Circuit A1 from fuse 6 in the Power
Distribution Center (PDC) supplies voltage to circuit
A21. Circuit A1 is HOT at all times.
Circuit F87 connects to the cluster connector to
power the gauges and to the telltale connector to
power the warning lamps.
Circuit E2 from fuse 19 in the fuse block feeds the
illumination lamps. Circuit E2 originates at the head-
lamp switch and continues through fuse 19. The
headlamp switch powers circuit E2 when the parking
lamps or headlamp are ON.
Circuit Z2 provides ground for the indicator lamps
and illumination lamps.
ENGINE COOLANT TEMPERATURE GAUGE
Circuit G20 connects the engine coolant tempera-
ture gauge to the engine coolant temperature sensor.
The sensor is a variable resistor and case grounded to
the engine. Circuit F87 connects to the instrument
cluster left connector and supplies voltage for the
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 current
passing through the coils to ground at the sensor.
ENGINE COOLANT TEMPERATURE WARNING
LAMP
Circuit G20 connects the engine coolant tempera-
ture warning lamp to the engine coolant temperature
switch. When the switch closes, battery voltage from
circuit F87 flows through the lamp to ground through
the switch on circuit G20. The engine coolant tem-
perature switch is case grounded to the engine. Cir-cuit F87 connects to the instrument cluster connector
and supplies voltage for the lamp.
Circuit G20 also connects to the warning lamp to
ground when the ignition switch is in the START
position. When the ignition switch is in the START
position, the lamp illuminates for a bulb test.
FUEL GAUGE
The fuel level sensor is a variable resistor. Circuit
G4 connects the fuel level sensor to the fuel gauge in
the instrument cluster. Circuit F87 from fuse 17 in
the fuse block supplies voltage to the fuel gauge. The
fuel level sensor draws voltage from circuit F87
through the fuel gauge on circuit G4. Circuit G4
connects to circuit 57 in the fuel pump module har-
ness. Circuit 57 connects to the fuel level sensor.
Circuit 99 in the fuel pump module harness con-
nects to circuit Z1. Circuit Z1 provides the ground
path for the fuel level sensor. The grounding point for
circuit Z1 is the left side of the cowl panel.
As current flows through the coils in the fuel gauge,
it creates a magnetic field. One of the coils in the
gauge receives fixed current. The other coil is con-
nected to the level sensor. The magnetic field controls
the position of the fuel gauge pointer.
The fuel level sensor contains a variable resistor. As
the position of the float arm on the fuel level sensor
changes, the resistor changes the current flow
through second coil in the fuel gauge. A change in
current flow alters the magnetic field in the fuel
gauge, which changes the pointer position.
LOW FUEL WARNING LAMP
Circuit G4 connects the fuel level sensor to the fuel
gauge. The low fuel level module at the rear of the
gauge monitors resistance in circuit G4. The low fuel
level module powers an light emitting diode (LED)
when the resistance in circuit G4 reaches a calibrated
level. The LED illuminates the Low Fuel indicator.
Refer to Group 8E for additional information.
J8W-40 INSTRUMENT CLUSTERÐXJ VEHICLES 8W - 40 - 1

CHARGING SYSTEM INDICATOR LAMP
The Powertrain Control Module (PCM) illuminates
the charging system indicator lamp by providing
ground for the lamp on circuit G12. Circuit G12 con-
nects to cavity 36 of the PCM. Circuit F87 supplies
battery voltage to the lamp.
FOUR-WHEEL DRIVE (4WD) SWITCH
When the 4WD switch closes, circuit Z1 provides
ground for the 4WD indicator lamp in the instrument
cluster. Circuit F87 connects to the instrument clus-
ter and supplies battery voltage to the 4WD indicator
lamp. Circuit 107 connects the indicator lamp to the
4WD switch. Circuit 106 connects the lamp to the in-
strument cluster and circuit F87.
CLUSTER GROUND
Circuit Z1 from the instrument cluster left connec-
tor provides ground for the illumination lamps and
indicator lamps.
HELPFUL INFORMATION
²If the warning lamps don't operate, check fuse 14
in the fuse block.
²If the indicator lamps and illumination lamps
don't operate, check fuse 13 in the fuse block.
²Inspect the ground at the instrument panel lower
right reinforcement support.
DIAGRAM INDEX
Component Page
4WD Switch............................8W-40-9
4WD Indicator Lamp......................8W-40-9
ABS Control Module......................8W-40-9
Brake Warning Switch.....................8W-40-10
Chime/Buzzer Module......................8W-40-8
Daytime Running Lamps Module.............8W-40-5, 6
Engine Coolant Temperature Sending Unit.........8W-40-6
Engine Oil Pressure Sending Unit..............8W-40-6
Fuse 3 (PDC)...........................8W-40-8
Fuse 5 (PDC)...........................8W-40-4
Fuse 6 (PDC).........................8W-40-4, 8
Fuse 11 (PDC)..........................8W-40-8
Fuse 16 (PDC)..........................8W-40-8
Fuse 9 (Fuse Block).......................8W-40-8
Fuse 15 (Fuse Block)......................8W-40-4
Fuse 17 (Fuse Block)....................8W-40-4, 8
Fuse 19 (Fuse Block)......................8W-40-4
Headlamp Switch.......................8W-40-4, 5
Headlamp Delay Module....................8W-40-8
Headlamp Dimmer Switch...................8W-40-5
Ignition Switch......................8W-40-4, 8, 10
Instrument Cluster......................8W-40-4, 5
Low Washer Fluid Lamp Switch...............8W-40-8
Park Brake Switch.......................8W-40-10
Powertrain Control Module..................8W-40-6
Remote Keyless Entry Module................8W-40-8
Telltale Connector (Instrument Cluster).....8W-40-7 thru 10
J8W-40 INSTRUMENT CLUSTERÐXJ VEHICLES 8W - 40 - 3

FUEL/IGNITION
INDEX
page page
Automatic Shut Down (ASD) Relay............. 1
Battery Feed.............................. 1
Brake Switch Input......................... 5
Camshaft Position Sensor.................... 3
Crankshaft Position Sensor................... 3
Data Link Connector........................ 4
Diagram Index............................ 5
Engine Coolant Temperature Sensor............ 3
Fuel Injectors............................. 1
Fuel Pump Module......................... 2
Fuel Pump Relay.......................... 2
Heated Oxygen Sensor...................... 3Idle Air Control (IAC) Motor................... 2
Ignition Coil.............................. 2
Ignition Feed............................. 1
Ignition Switch............................ 1
Intake Air Temperature Sensor................ 4
Malfunction Indicator Lamp (MIL)............... 4
Manifold Absolute Pressure Sensor............. 4
Park/Neutral Position Switch.................. 4
Power (Device) Ground...................... 5
Tachometer Signal......................... 4
Throttle Position Sensor..................... 4
Vehicle Speed Sensor....................... 2
IGNITION SWITCH
Circuit A1 from fuse 11 in the power distribution
center (PDC), supplies battery voltage to the ignition
switch. Depending upon position, the ignition switch
powers circuits A21, A38, A41, or A48.
START POSITION
In the START position, the ignition switch connects
circuit A1 to circuit A41. Circuit A41 connects to the
coil side of the starter motor relay.
Additionally in the START position, the case
grounded ignition switch provides ground for the
brake lamp switch and the warning lamps in the in-
strument cluster.
START OR RUN POSITION
In the START or RUN position, the ignition switch
connects circuit A1 to circuit A21. Circuit A21 splices
to power the coil side of the Automatic Shut Down
(ASD) relay and the fuel pump relay.
RUN (ONLY) POSITION
When the ignition switch is in the RUN position, it
connects circuit A1 to circuit A38. Circuit A38 feeds
circuit L39.
ACCESSORY OR RUN POSITIONS
In the ACCESSORY or RUN positions, the ignition
switch connects circuit A1 to circuit A48. Circuit A48
connects to a bus bar in the fuse block.
AUTOMATIC SHUT DOWN (ASD) RELAY
When the ignition switch is in either the START or
RUN positions, it connects circuit A1 from fuse 6 in
the Power Distribution Center (PDC) to circuit A21.
Circuit A21 supplies battery voltage to the coil side of
the Automatic Shut Down (ASD) relay. The Power-train Control Module (PCM) provides ground for the
relay on circuit K51. Circuit K51 connects to cavity
51 of the PCM.
When the PCM grounds the ASD relay, contacts in-
side the relay close and connect circuit A18 from fuse
14 in the PDC to circuit A142. Circuit A142 splices to
the generator field terminal, fuel injectors, and igni-
tion coil. Circuit A142 also connects to cavity 57 of
the PCM.
HELPFUL INFORMATION
²Along with supplying voltage to the coil side of the
ASD relay, circuit A21 also supplies voltage to the
coil side of the fuel pump relay.
²Circuit A21 also connects to cavity 9 of the PCM.
BATTERY FEED
Circuit A14 from fuse 2 in the power distribution
center supplies battery voltage to cavity 3 of the
Powertrain Control Module (PCM).
HELPFUL INFORMATION
Circuit A14 also supplies power to the contact sides
of the fuel pump relay and fuse F2 in the PDC. Fuse
F2 powers circuit A18 which supplies voltage to the
contact side of the automatic shut down relay.
IGNITION FEED
When the ignition switch is in either the START or
RUN positions, it connects circuit A1 from fuse 6 in
the Power Distribution Center (PDC) to circuit A21.
Circuit A21 also connects to cavity 9 of the PCM and
provides the ignition input.
FUEL INJECTORS
When the Automatic Shut Down (ASD) relay con-
tacts close, they connect circuits A18 and A142. Cir-
J8W-30 FUEL/IGNITIONÐXJ-RHD 8W - 30 - 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