engine FORD MUSTANG 2003 Workshop Manual

PINPOINT TEST B: THE ENGINE DOES NOT CRANK AND THE
RELAY DOES NOT CLICK
Test Step Result / Action to Take
B1 CHECK CIRCUIT 33 (WH/PK) FOR VOLTAGE
z
Disconnect: Starter Motor Relay.
z Key in START position.
z Measure the voltage between the starter motor relay pin 85,
circuit 33 (WH/PK) and ground while holding the key in the
START position.
z Is the voltage greater than 10 volts? Yes
GO to
B10 .
No
For automatic
transmissions, GO to
B2 . For manual
transmissions, GO to
B5 .
B2 CHECK CIRCUIT 32 (RD/LB) FOR VOLTAGE AT THE DIGITAL
TR SENSOR z
Key in OFF position.
z Disconnect: Digital TR Sensor C110.
z Key in START position.
z Measure the voltage between the digital TR sensor C110 pin
10, circuit 32 (RD/LB) and ground while holding the key in the
START position.
z Is the voltage greater than 10 volts? Yes
GO to
B3 .
No
GO to B7 .
B3 CHECK CIRCUIT 33 (WH/PK) FOR OPEN
z
Key in OFF position.
z Measure the resistance between the digital TR sensor C110 pin Yes
GO to
B4 .
No
REPAIR circuit 33
(WH/PK). TEST the
system for normal
operation. Klj . 4 ba
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PINPOINT TEST C: THE ENGINE CRANKS SLOWLY
PINPOINT TEST D: UNUSUAL STARTER NOISE z
Measure the resistance between the starter motor relay pin 86,
circuit 1205 (BK) and ground.
z Is the resistance less than 5 ohms? Test Step Result / Action to Take
NOTE:
Before beginning this test, be sure that the battery is tested and fully charged. C1 CHECK THE VOLTAGE TO THE STARTER
z
Key in OFF position.
z Measure the voltage between the starter motor
solenoid positive terminal and ground.
z Is the voltage 12.5 volts or greater? Yes
GO to
C2 .
No
REPAIR the circuit between the
battery and the starter solenoid.
CLEAN and TIGHTEN the
connections at the battery terminals.
TEST the system for normal
operation. C2 CHECK MOTOR GROUND CIRCUIT
z
Carry out the Motor Ground Circuit test; refer to
Component Tests in this section.
z Is the ground OK? Yes
INSTALL a new starter motor.
REFER to
Starter Motor — 3.8L or
Starter Motor — 4.6L . TEST the
system for normal operation.
No
REPAIR the ground circuit as
necessary. TEST the system for
normal operation. Test Step Result / Action to Take
D1 CHECK THE STARTER MOTOR
MOUNTING z
Inspect the starter motor mounting Yes Klj . 7 ba
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reading is still greater than 0.5 volts when checked at the M-
terminal and less than 0.5 volts
when checked at the B- terminal, the concern is in the solenoid contacts. Install a new starter
motor. Refer to Starter Motor — 3.8L or
Starter Motor — 4.6L .
9. Clean the positive (+) battery cable connections. Repeat the test at the starter solenoid B terminal. If the voltage is greater than 0.5 volts, install a new positive battery cable.
Starter Motor— Ground Circuit
A slow cranking condition can be caused by resistance in the ground or return portion of the cranking
circuit. Check the voltage drop in the ground circuit as follows:
1. Connect the Digital Multimeter positive lead to the starter motor housing (the connection must be clean and free of rust or grease). Connect the negative lead to the negative (- ) battery
terminal.
2. Engage the remote starter switch. Read and record the voltage. The voltage reading should be less than 0.3 volts.
3. If the voltage is greater than 0.3 volts, clean the negative cable connections at the battery, body ground connections, and the starter ground connections. Retest.
4. If the voltage is greater than 0.3 volts, install a new cable. If the voltage reading is less than 0.2 volts and the engine still cranks slowly, install a new starter motor. Refer to Starter Motor — 3.8L
or
Starter Motor — 4.6L . Item Part Number Description
1 105-
R0057 Digital multimeter
2 10653 Battery
3 — S-
terminal 4 — M-
terminal 5 — B-
terminal 6 — Remote starter switch Klj . 10 ba
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6. Remove the starter motor.
Installation 1. Position the starter motor to the engine.
2. NOTE: To ease installation, first install the two lower bolts finger tight, then install the upper,
concealed bolt. Tighten all three bolts to specification.
Install the three starter motor bolts.
3. Connect the starter motor solenoid and starter motor cable connections.
4. Install the red starter solenoid safety cap.
5. Lower the vehicle.
6. Connect the battery ground cable. Klj . 2 ba
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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
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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
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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
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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
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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
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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
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