STARTING SYSTEM
INDEX
page page
Diagram Index............................ 1Starting System........................... 1
STARTING SYSTEM
AUTOMATIC TRANSMISSIONS
Circuit A0 from the battery is double crimped at
the positive battery post. One branch of circuit A0
(battery positive cable) connects to the engine starter
motor. The other A0 branch supplies voltage to the
bus bar in the power distribution center (PDC).
Fuse 7 in the PDC supplies battery voltage to the
contact side of the engine starter motor relay on cir-
cuit A4. When the coil side of the engine starter mo-
tor relay energizes, the contacts close and connect
circuit A4 to circuit T40. Circuit T40 supplies battery
voltage to the starter motor solenoid.
The ignition switch supplies battery voltage to the
coil side of the starter motor relay on circuit A41
when the key is moved to the START position and
the PARK/NEUTRAL position switch is closed.
Ground for the coil side of the starter motor relay is
supplied by the case grounded PARK/NEUTRAL po-
sition switch. Circuit T41 connects the coil side of the
relay to the PARK/NEUTRAL position switch.
When the starter motor relay energizes and the
contacts close, circuit T40 supplies battery voltage to
the starter motor solenoid. Circuit A0 from the bat-
tery supplies voltage to the starter motor when the
solenoid energizes.
MANUAL TRANSMISSIONS
Circuit A0 from the battery is double crimped at
the positive battery post. One branch of circuit A0
(battery positive cable) connects to the battery
starter motor. The other A0 branch supplies voltage
to the buss bar in the power distribution center
(PDC).
Fuse 7 in the PDC supplies battery voltage to the
contact side of the engine starter motor relay on cir-
cuit A4. When the coil side of the engine starter mo-
tor relay energizes, the contacts close and connect
circuit A4 to circuit T40. Circuit T40 supplies battery
voltage to the starter motor solenoid.The ignition switch supplies battery voltage to the
coil side of the starter motor relay on circuit A41
when the key is moved to the START position. Cir-
cuit Z12 provides ground for the coil side of the relay.
When the starter motor relay energizes and the
contacts close, circuit T40 supplies battery voltage to
the starter motor solenoid. Circuit A0 from the bat-
tery supplies voltage to the starter motor when the
solenoid energizes.
HELPFUL INFORMATION
²The Park/Neutral switch closes when the trans-
mission is in either the PARK or NEUTRAL posi-
tions.
²Circuit T41 also connects to cavity 30 of the pow-
ertrain control module (PCM). This input tells the
PCM the operator is starting the vehicle.
²Circuit A4 is double crimped at the contact side of
the starter motor relay. The A4 branch leaving the
relay powers fuse 13 in the PDC.
DIAGRAM INDEX
Component Page
Battery (2.5L)...........................8W-21-2
Battery (4.0L)...........................8W-21-3
Engine Starter Motor (2.5L)..................8W-21-2
Engine Starter Motor (4.0L)..................8W-21-3
Engine Starter Motor Relay (2.5L)..............8W-21-2
Engine Starter Motor Relay (4.0L)..............8W-21-3
Ignition Switch (2.5L)......................8W-21-2
Ignition Switch (4.0L)......................8W-21-3
PDC Fuse 6 (2.5L).......................8W-21-2
PDC Fuse 6 (4.0L).......................8W-21-3
PDC Fuse 7 (2.5L).......................8W-21-2
PDC Fuse 7 (4.0L).......................8W-21-3
Powertrain Control Module (2.5L)..............8W-21-2
Powertrain Control Module (4.0L)..............8W-21-3
Park/Neutral Position Switch (2.5L).............8W-21-2
Park/Neutral Position Switch (4.0L).............8W-21-3
J8W-21 STARTING SYSTEMÐXJ VEHICLES 8W - 21 - 1
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