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
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 (MAP) 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
²Manifold absolute pressure sensor
²Engine coolant temperature sensor
²Vehicle speed sensor
MANIFOLD ABSOLUTE PRESSURE (MAP) 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 Powertrain
Control Module (PCM). The park/neutral position
switch provides an input to the (PCM).
HELPFUL INFORMATION
²In the START position, the ignition switch con-
nects circuit A1 from the Power Distribution Center
(PDC) to circuit A41. Fuse 4 in the fuse block pro-
tects circuits A1 and A41.
²The Park/Neutral position switch and back-up
lamp switch are molded together.
POWER STEERING PRESSURE SWITCH
The Powertrain Control Module (PCM) supplies
voltage to the power steering pressure switch on cir-
cuit K10. Circuit Z1 provides ground for the switch.
When the switch closes, voltage flows through the
8W - 30 - 4 8W-30 FUEL/IGNITIONÐYJ VEHICLESJ
switch to ground on circuit Z1. The switch closes dur-
ing periods of high power steering pump load and
low engine speed; such as parking maneuvers. Cir-
cuit K10 connects to cavity 10 of the PCM.
TACHOMETER SIGNAL
The Powertrain Control Module (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 G5
provides voltage for the lamp.
DATA LINK CONNECTOR
Circuit G50 supplies battery voltage to the data
link connector. Circuit G50 originates at fuse 5 in the
fuse block. Circuit G50 is double crimped at the data
link connector and connects to cavity 9 of the Power-
train Control Module (PCM).
Circuit A21 from the ignition switch powers fuse 5
when the switch is in the START or RUN positions.
In the START or RUN position the ignition switch
connects circuit A1 from fuse 4 in the Power Distri-
bution Center (PDC) with circuit A21.
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 splices to circuit Z1 which termi-
nates 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 Z1 and Z11 cir-
cuits at the right rear of the engine, the vehicle will
not operate. Check the connection at the ganged-
ground circuit eyelet.
BRAKE SWITCH INPUT
Circuit V40 provides the brake switch input to the
Powertrain Control Module (PCM). Circuit V40 con-
nects to cavity 29 of the PCM.
POWER (DEVICE) GROUND
Circuit Z11 connects to cavities 11 and 12 of the
Powertrain Control Module (PCM). The Z1 circuit
provides ground for PCM internal drivers that oper-
ate high current devices like the injectors and igni-
tion 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 Z1 is the right rear
of the engine.
²If the system loses ground for the Z1 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, 14
Camshaft Position Sensor................8W-30-10, 16
Crankshaft Position Sensor...............8W-30-10, 16
Data Link Connector...................8W-30-11, 17
Daytime Running Lamps (DRL) Module.......8W-30-11, 17
Engine Coolant Temperature Sensor..........8W-30-9, 18
Fuel Pump Relay........................8W-30-20
Fuel Tank Level Unit......................8W-30-21
Fuse 1 (PDC)........................8W-30-6, 14
Fuse 4 (PDC)........................8W-30-6, 14
Fuse 5 (Fuse Block).................8W-30-6, 14, 20
Heated Oxygen Sensor..................8W-30-7, 15
Idle Air Control Motor..................8W-30-12, 18
Ignition Switch.....................8W-30-6, 14, 20
Ignition Coil........................8W-30-12, 18
Injectors (4.0L).........................8W-30-13
Injectors (2.5L)..........................8W-30-8
Instrument Cluster....................8W-30-11, 17
Intake Air Temperature Sensor.............8W-30-9, 18
MAP Sensor.........................8W-30-9, 18
Power Steering Pressure Switch..............8W-30-12
Powertrain Control Module.............8W-30-6 thru 21
Throttle Position Sensor.................8W-30-9, 18
Vehicle Speed Sensor..................8W-30-11, 17
J8W-30 FUEL/IGNITIONÐYJ VEHICLES 8W - 30 - 5
HORN/CIGAR LIGHTER
HORN
The horn system uses a switch and horn relay. The
horn switch is in the center of the steering wheel.
Circuit A4 from fuse 8 in the Power Distribution
Center (PDC) feeds circuit F31 through fuse 15 in
the PDC. Circuit F31 is HOT at all times and powers
the coil and contact sides of the horn relay.
When the case grounded horn switch is pressed,
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 horn. Circuit Z1
provides ground for the horn.
HELPFUL INFORMATION
²The horn switch is grounded to the steering wheel.
²Circuit F31 is double crimped at the coil side of
the horn relay.
²Check fuse 8 in the PDC and fuse 15 in the fuse
block.
CIGAR LIGHTER
In the ACCESSORY or RUN position, the ignition
switch supplies voltage to fuse 7 in the fuse block on
circuit A31. Fuse 7 feeds circuit F30 which connects
to the cigar lighter. When the lighter is depressed,
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 4 in the PDC
with circuit A31.
²Circuit F30 also powers the radio and radio relay.
DIAGRAM INDEX
Component Page
Cigar Lighter...........................8W-41-3
Fuse 4 (PDC)...........................8W-41-3
Fuse 8 (PDC)...........................8W-41-2
Fuse 11 (PDC)..........................8W-41-2
Fuse 7 (Fuse Block).......................8W-41-3
Horn.................................8W-41-2
Horn Relay.............................8W-41-2
Horn Switch............................8W-41-2
Ignition Switch..........................8W-41-3
J8W-41 HORN/CIGAR LIGHTERÐYJ VEHICLES 8W - 41 - 1
CONNECTOR LOCATIONS
GENERAL INFORMATION
This section provides illustrations identifying com-
ponent and connector locations in the vehicle. A con-nector index is provided. Use the wiring diagrams in
each section for connector number identification. Re-
fer to the index for the proper figure number.
CONNECTOR LOCATIONS
Connector # . Color . Location Fig.
C101......BK ...RTFender Side Shield..........1
C102......BK ...RTFender Side Shield Under PDC . .1
C103......BK ...RTFender Side Shield..........1
C104......BK ...LTSide of Battery on Cowl Panel . . .1
C105 2.5L . . . NAT . . RT Rear of Engine............3
C105 4.0L . . . NAT . . RT Rear of Engine............4
C106......BK ...AtLamp...................1
C107......NAT ..Center of Cowl Panel Near
Map Sensor...............1
C108......BK ...LTKick Panel Above Park Brake . . .8
C109......BK ...Under Drivers Seat............8
C110......BK ...Under I.P.Front of Floor Tunnel....6
C111......BK ...Under I.P.Front of Floor Tunnel....6
C112......BK ...Under I.P. RT of Stop Lamp Switch .7
C113......BK ...LTFender Side Shield..........1
C114......BK ...LTSide Cowl Panel............1
C115......BK ...LTFender Side Shield..........1
C116......BK ...LTFender Side Shield..........1
C117......BK ...LTFender Side Shield..........1
C118......BK ...Bottom of Washer Reservoir......2
C119......BK ...Near Bulkhead Disconnect
2.5L only..........Not Shown
C120 2.5L . . . BK . . . Rear of Generator.............3
C120 4.0L . . . BK . . . Rear of Generator.............5
C121 2.5L . . . BK . . . RT Rear of Engine............3
C121 4.0L . . . BK . . . Rear of Generator.............4
C122......BK ...OnReceiver/Drier.............4
C123 2.5L . . . BK . . . RT Side of Engine Rear of Distributor .3
C123 4.0L . . . BK . . . RT Side of Engine Rear of Distributor .4
C124 2.5L . . . BK . . . At End of Distributor Pig Tail.....3
C124 4.0L . . . BK . . . At End of Distributor Pig Tail.....4
C125......GY ...RTSide of Transmission........5
C126......BK ...LTRear of Transmission.........5
C127......BK ...TopofFuel Tank..............9
C128......BK ...TopofRear Cross-member.......9
C129......BK ...TopofRear Cross-member.......9
C130 2.5L . . . BK . . . On Thermostat Housing.........3
C130 4.0L . . . BK . . . On Thermostat Housing.........4
C131 2.5L . . . BK . . . LT Side of Engine Bottom of Intake .3
C131 4.0L . . . BK . . . LT Side of Engine Bottom of Intake .4
C132 2.5L . . . BK . . . Injector #1.................3
C132 4.0L . . . BK . . . Injector #1.................4
C133 2.5L . . . BK . . . Injector #2.................3
C133 4.0L . . . BK . . . Injector #2.................4
C134 2.5L . . . BK . . . Injector #3.................3
C134 4.0L . . . BK . . . Injector #3.................4
C135 2.5L . . . BK . . . Injector #4.................3
C135 4.0L . . . BK . . . Injector #4.................4Connector # . Color . Location Fig.
C136......BK ...Injector #5.................4
C137......BK ...Injector #6.................4
C138 2.5L . . . BK . . . Center of Dash Panel...........1
C138 4.0L . . . BK . . . Center of Dash Panel...........1
C139......BK ...Under Bulkhead LT Side of I.P.....1
C140 2.5L . . . GY . . . LT Rear of Intake.............3
C140 4.0L . . . GY . . . LT Rear of Intake.............4
C141 2.5L . . . BK . . . Rear of Throttle Body..........3
C141 4.0L . . . BK . . . Rear of Throttle Body..........4
C142 2.5L . . . BK . . . On Throttle Body.............3
C142 4.0L . . . BK . . . On Throttle Body.............4
C143 2.5L . . . BK . . . Rear of Intake...............3
C143 4.0L . . . BK . . . Rear of Intake...............4
C144......BK ...Above Bulkhead Disconnect.......1
C145......GY ...OnPower Steering Pump........3
C146......BK ...AtHeadlamp..........Not Shown
C147......YL ...AtSide Marker Lamp..........2
C148......BK ...AtPark/Turn Lamp......Not Shown
C149......BK ...RTSide Behind Bumper.........2
C150......BK ...LTSide Behind Bumper.........2
C151......BK ...AtPark/Turn Lamp............2
C152......YL ...AtSide Marker Lamp. . . .Not Shown
C153......BK ...AtHeadlamp................2
C154......BK ...LTFender Side Shield..........2
C155......BK ...Direct Connection to Horn.......2
C156......BK ...Bottom of Washer Reservoir......2
C201......BK ...LTSide of I.P...............7
C202......BK ...OnFuse Block...............7
C203......BK ...LTKick Panel................7
C204......BK ...LTKick Panel................7
C205......BK ...LTSide Kick Panel Under I.P......7
C206......BK ...AtSpeaker...........Not Shown
C207......BK ...LTofSteering Column Rear
of Cluster.................7
C208......BK ...LTSide of Steering Column......7
C209......BK ...Rear of Switch...............7
C210......BK ...Rear of Switch...............7
C211......BK ...Base of Steering Column........7
C212......BK ...AtWiper Motor..............7
C213......BK ...RTofSteering Column Under I.P. . .7
C214......BK ...RTSide of Cluster Bezel . .Not Shown
C215......BK ...Base of Steering Column........7
C216......BK ...Base of Steering Column........7
C217......BK ...RTSide of Brake Pedal Support . . .7
C218......BK ...Base of Steering Column........7
C219......BK ...Rear of Switch...............7
C220......BK ...Rear of Switch...............7
C221......BK ...Rear of Switch...............7
J8W-90 CONNECTOR LOCATIONSÐYJ VEHICLES 8W - 90 - 1