ignition FORD MUSTANG 2003 Workshop Manual

z
Measure the voltage between the central junction box fuse 6,
circuit 33 (WH/PK) and ground while holding the key in the
START position.
z Is the voltage greater than 10 volts? system for normal
operation.
No
GO to
B8 .
B8 CHECK CIRCUIT 1050 (LG/VT) FOR VOLTAGE
z
Key in OFF position.
z Disconnect: Ignition Switch C209.
z Key in ON position.
z Measure the voltage between the ignition switch connector
C209 pin B4, circuit 1050 (LG/VT) and ground.
z Is the voltage greater than 10 volts? Yes
GO to
B9 .
No
REPAIR circuit 1050
(LG/VT). TEST the
system for normal
operation. B9 CHECK THE IGNITION SWITCH
z
Carry out the ignition switch component test. Refer to
Refer to Wiring Diagrams Cell 149 for schematic and connector
information.
.
z Does the ignition switch test good? Yes
REPAIR circuit 33
(WH/PK). TEST the
system for normal
operation.
No
INSTALL a new ignition
switch. TEST the
system for normal
operation.
B10 CHECK CIRCUIT 1205 (BK) FOR OPEN
z
Key in OFF position. Yes
INSTALL a new starter
motor relay. TEST the
system for normal
operation.
No
REPAIR circuit 1205
(BK). TEST the system
for normal operation. Klj . 6 ba
112003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_4464/S3B~us~en~ ...

Component Tests
Starter Motor —Voltage Drop Test
WARNING: When servicing starter motor or carrying out other underhood work in the
vicinity of the starter motor, be aware that the heavy gauge battery input lead at the starter
solenoid is "electrically hot" at all times. A protective cap or boot is provided over this terminal
that must be installed after servicing. Be sure to disconnect the battery negative cable before
servicing the starter. Failure to follow these instructions may result in personal injury.
WARNING: When using a remote starter switch or jumper wire, be sure the ignition switch
is in the OFF position and the transmission is in PARK (A/T) or Neutral (M/T) with the parking
brake control fully applied.
Always make the Digital Multimeter connections at the component terminal rather than at the wiring
end connector. Making a connection at the wiring end connector could result in false readings because
the meter will not pick up a high resistance between the wiring connector and the component.
Starter Motor— Motor Feed Circuit
1. Make sure the battery is fully charged. Perform a battery load test. For additional information, refer to Section 414 - 00 .
2. Disconnect the inertia fuel shut off (IFS) switch.
3. Connect a remote starter switch between the starter solenoid S- terminal and the battery positive
(+) terminal.
4. Connect the Digital Multimeter positive lead to the battery positive (+) post. Connect negative lead to the starter solenoid M- terminal. brackets for cracks.
z Check the starter motor mounting
bolts for looseness.
z Is the starter motor mounted
correctly? GO to
D2 .
No
REINSTALL the starter motor correctly. REFER to
Starter Motor — 3.8L or
Starter Motor — 4.6L in this
section. D2 INSPECT THE STARTER MOTOR
z
Remove the starter motor; refer to
Starter Motor — 3.8L or
Starter Motor — 4.6L in this section.
z Inspect the starter motor for
damage.
z Is the starter motor damaged? Yes
INSTALL a new starter motor. REFER to
Starter Motor — 3.8L or
Starter Motor — 4.6L in this section.
TEST the system for normal operation.
No
CHECK the starter drive. REFER to Component
Tests, Starter Drive Test in this section. INSTALL a
new starter motor. TEST the system for normal
operation. Klj . 8 ba
112003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_4464/S3B~us~en~ ...

SPECIFICATIONS
SECTION 303-
07A: Engine Ignition — 3.8L 2003 Mustang Workshop Manual General Specifications
Item Specification
Base ignition timing TBD
Firing order 1-4-2-5-3-
6 Spark plug gap mm (in) 1.32-
1.42 (0.052- 0.056) Spark plug type production LH AWSF-
42E Spark plug type production RH AWSF-
42EG Spark plug type service AWSF-
42EE Silicone Brake Caliper Grease and Dielectric Compound D7AZ-19A331-
A ESE-
M1C171- A
Torque Specifications Description Nm lb-
ft lb-
in Spark plugs 15 11 —
Ignition coil bolts 7 — 52 Klj . 1 ba
12003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_4464/S3B~us~en~ ...

DESCRIPTION AND OPERATION
Engine Ignition
The ignition coil (12029), which is mounted on the upper intake manifold, can be described as a coil
pack containing three separate coil units. Each coil unit is individually controlled by the powertrain
control module (PCM) (12A650) through separate wire leads. Each coil unit activates two spark plugs
wired in a series by the spark plug wires (12286).
zOne spark plug activates on the compression stroke and uses the majority of the ignition coil's
stored energy.
z The other spark plug activates on the exhaust stroke and uses very little of the ignition coil's
stored energy.
z Because the pairs of spark plugs are connected in a series, one spark will travel from ground to
the electrode while the other spark will travel from the electrode to ground.
The spark plug (12405):
zchanges the high voltage pulse into a spark which ignites the fuel and air mixture.
z originally equipped on the vehicle has a platinum- enhanced active electrode for long life.
The crankshaft position (CKP) sensor (6C315):
NOTE: Initial engine ignition timing is set at 10 degrees ± 2 degrees before top dead center (BTDC)
and is not adjustable.
zis a variable reluctance sensor triggered by a 36- minus-1 tooth trigger pulse wheel located on
the crankshaft (6303) inside the engine front cover (6019).
The sine wave type signal generated from the crankshaft position sensor provides two types of
information:
zposition of the crankshaft in 10 degree increments
z the crankshaft speed (rpm)
The powertrain control module (PCM) (12A650) uses this information to determine ignition coil turn ON
and turn OFF times and misfire detection.
For additional information, refer to Section 303 - 14 .
SECTION 303-
07A: Engine Ignition — 3.8L 2003 Mustang Workshop Manual Klj . 1 ba
22003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_4464/S3B~us~en~ ...

DIAGNOSIS AND TESTING
Engine Ignition
Refer to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.
SECTION 303-
07A: Engine Ignition — 3.8L 2003 Mustang Workshop Manual Klj . 1 ba
12003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_4464/S3B~us~en~ ...

REMOVAL AND INSTALLATION
Ignition Coil
Removal and Installation
1. Disconnect the battery ground cable (14301). For additional information, refer to Section 414 -
01 .
2. Disconnect the ignition coil electrical connector.
3. CAUTION: Spark plug wires (12286) must be connected to the correct ignition coil
terminal. Mark spark plug wire locations before removing them.
Twist while pulling upward to disconnect the spark plug wires.
4. Disconnect the accelerator cable retaining clamp from the ignition coil stud bolt.
SECTION 303-
07A: Engine Ignition — 3.8L 2003 Mustang Workshop Manual Material
Item Specification
Silicone Brake Caliper Grease
and Dielectric Compound
D7AZ-
19A331-A or equivalent ESE-
M1C171-
A Klj . 1 ba
22003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_4464/S3B~us~en~ ...

5. Remove the bolts and the ignition coil (12029).
6.
NOTE: Apply silicone brake caliper grease and dielectric compound to the inside of the spark
plug wire coil boot.
NOTE: Be sure to reinstall the radio ignition interference capacitor (18801) under the correct
mounting bolt.
To install, reverse the removal procedure. Klj . 2 ba
22003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_4464/S3B~us~en~ ...

REMOVAL AND INSTALLATION
Spark Plug Wire
Removal and Installation
CAUTION: It is important to twist the spark plug wire boots while pulling upward to avoid
possible damage to the spark plug wire.
CAUTION: Spark plug wires must be connected to the correct ignition coil terminal. Mark
spark plug wire (12286) locations before removing them.
1. Using the special tool, remove the spark plug wire from the spark plug using a twisting motion.
2. Twist while pulling upward to disconnect the spark plug wires from the ignition coil (12029).
SECTION 303-
07A: Engine Ignition — 3.8L 2003 Mustang Workshop Manual Special Tool(s)
Remover, Spark Plug Wire
303-
106 (T74P- 6666A)
Material Item Specification
Silicone Brake Caliper Grease
and Dielectric Compound
D7AZ-
19A331-A or equivalent ESE-
M1C171-
A Klj . 1 ba
22003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_4464/S3B~us~en~ ...

3.
CAUTION: Be sure to orient the spark plug boots so the spark plug wires do not
contact the exhaust manifold.
NOTE: Apply silicone brake caliper grease and dielectric compound to the inside of spark plug
and ignition coil boots of the spark plug wire.
To install, reverse the removal procedure. Klj . 2 ba
22003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_4464/S3B~us~en~ ...

REMOVAL AND INSTALLATION
Spark Plugs
Removal and Installation
CAUTION: It is important to twist the spark plug wire boots while pulling upward to avoid
possible damage to the spark plug wire.
CAUTION: Spark plug wires must be connected to the correct ignition coil terminal. Mark
spark plug wire (12286) locations before removing them.
1. Remove the air cleaner outlet pipe. For additional information, refer to Section 303 - 12 .
2. Using the special tool, remove the spark plug wires from the spark plugs using a twisting motion.
3. NOTE: Use compressed air to remove any foreign material from the spark plug well before
removing the spark plugs.
NOTE: If an original spark plug is reused, make sure it is installed in the same cylinder from
which it was taken. New spark plugs can be used in any cylinder.
NOTE: Left side shown, right side similar.
Remove the spark plugs.
SECTION 303-
07A: Engine Ignition — 3.8L 2003 Mustang Workshop Manual Special Tool(s)
Remover, Spark Plug Wire
303-
106 (T74P- 6666A)
Material Item Specification
Silicone Brake Caliper Grease
and Dielectric Compound
D7AZ-
19A331-A or equivalent ESE-
M1C171-
A Klj . 1 ba
52003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_4464/S3B~us~en~ ...