2003 FORD MUSTANG manual transmission

19. Disconnect the transmission main control harness electrical connector.
20. Raise and support the vehicle. For additional information, refer to
Section 100 - 02 .
21. Disconnect the RH heated oxygen sensor (HO2S) electrical connector.
22. Disconnect the crankshaft position (CKP) sensor electrical connector.
23. Disconnect the air conditioning compressor electrical connector. Klj . 5 ba
72003 Mustang Workshop Manual
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Item Part
Number Description
1 — Engine control sensor wiring 42 pin electrical
connector
2 — 16 pin electrical connector
3 — Engine control jumper harness electrical connector
4 — RH heated oxygen sensor (HO2S) electrical
connector
5 — Transmission main control harness electrical
connector.
6 — Fuel injector electrical connectors
7 — Heated positive crankcase ventilation (PCV) valve
electrical connector.
8 — Radio ignition interference capacitor electrical
connector
9 — Ignition coil electrical connectors
10 — Generator battery electrical connector
11 — Generator field electrical connector
12 — Engine coolant temperature (ECT) sensor
electrical connector
13 — Fuel pressure sensor electrical connector
14 — Exhaust vacuum regulator (EVR) electrical
connector
15 — Idle air control (IAC) electrical connector
16 — EGR backpressure transducer electrical connector
17 — Power distribution box battery feed electrical wire
18 — Camshaft position (CMP) sensor electrical
connector Klj . 2 ba
32003 Mustang Workshop Manual
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11. Disconnect the transmission main control harness electrical connector.
12. Disconnect the engine control jumper harness electrical connector.
13. Remove the wiring harness bracket bolt.
14. Disconnect the RH heated oxygen sensor (HO2S) electrical connector. Klj . 3 ba
112003 Mustang Workshop Manual
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12. Connect the transmission main control harness electrical connector.
13. Connect the LH ignition coil electrical connectors.
14. Install the LH ignition coil cover and bolts.
15. Connect the heated positive crankcase ventilation (PCV) vlave electrical connector. Klj . 9 ba
112003 Mustang Workshop Manual
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DESCRIPTION AND OPERATION
Starting System
Starter Motor
The starter motor is a 12-
volt unit that has the starter solenoid mounted on the drive end housing and
functions as follows:
zThe current flows through the solenoid energizing coil until the solenoid plunger is at the end of
its travel.
z The plunger closes a set of contacts that bypass the energizing coil, letting the holding coil keep
the starter drive engaged and passing starting current to the starter motor.
z The motor is energized when the starter solenoid contacts are closed.
z The starter drive engages the flywheel ring gear and starts the engine.
z An overrunning clutch in the starter drive protects the starter motor from excessive speed when
the engine starts.
Starter Relay
The starter interrupt relay consists of:
zpull in coil and contacts
When the ignition switch is in the START position:
zthe pull- in coil is activated and pulls the contacts together.
z current passes through the starter relay from the engine compartment power distribution box to
the starter solenoid.
Clutch Pedal Position (CPP) Switch
The CPP switch for:
za manual transmission closes when the clutch pedal is depressed, completing the starting
circuit.
z an automatic transmission is a jumper inserted in place of the CPP switch to complete the
circuit.
Starter System — Operation
When the ignition switch is turned to the START position the starter relay switches power to the starter
solenoid causing the starter motor to engage as long as:
zthe clutch pedal is depressed (manual transmission only).
z the digital transmission range (TR) sensor is in PARK or NEUTRAL (automatic transmission
only).
SECTION 303-
06: Starting System 2003 Mustang Workshop Manual Klj . 1 ba
22003 Mustang Workshop Manual
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DIAGNOSIS AND TESTING
Starting System
Refer to Wiring Diagrams Cell
20 , Starting System for schematic and connector information.
Inspection and Verification 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 working in area of the starter motor, be careful to avoid touching hot
exhaust components. 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.
1. Verify the customers concern by operating the starting system to duplicate the conditions.
2. Inspect to determine if any of the following mechanical or electrical concerns apply.
3. If the inspection reveals an obvious concern that can be readily identified, repair as necessary.
4. If the concern remains after the inspection, determine the symptom. GO to Symptom Chart .
SECTION 303-
06: Starting System 2003 Mustang Workshop Manual Special Tool(s)
Digital Multimeter
105-
R0051 or equivalent Visual Inspection Chart
Mechanical Electrical
z
Starter motor
z Brackets z
Battery
z Battery junction box (BJB) fuse ignition switch (40A)
z Central junction box (CJB) Fuse 6 (20A)
z Fuse 24 (10A)
z Damaged wiring harness
z Starter Relay
z Loose or corroded connections Klj . 1 ba
112003 Mustang Workshop Manual
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Symptom Chart
Pinpoint Tests
PINPOINT TEST A: THE ENGINE DOES NOT CRANK AND THE
RELAY DOES CLICK
SYMPTOM CHART Condition
Possible Sources Action
z The engine does
not crank and the
relay does click z
Battery.
z Fuse.
z Starter
motor/solenoid.
z Ignition switch.
z Circuit. z
Go To Pinpoint Test A .
z The engine does
not crank and the
relay does not
click z
Fuse.
z Battery.
z Starter relay.
z Ignition switch.
z Digital transmission
range (TR) sensor.
z Starter solenoid.
z Clutch pedal
position (CPP)
switch.
z Circuit. z
Go To Pinpoint Test B .
z The engine
cranks slowly z
Battery.
z Starter
motor/solenoid.
z Circuit. z
Go To Pinpoint Test C .
z Unusual starter
noise z
Starter motor
mounting.
z Starter motor.
z Incorrect starter
drive engagement. z
Go To Pinpoint Test D .
z The starter spins
but the engine
does not crank z
Starter Motor zINSPECT the starter motor
mounting and engagement.
REPAIR as necessary.
z Damaged
flywheel/ring gear
teeth. z
INSPECT the flywheel/ring
gear for damaged, missing or
worn teeth. REPAIR as
necessary. Test Step Result / Action to Take
A1 CHECK THE VOLTAGE TO THE STARTER RELAY
z
Measure the voltage between the starter relay pin 30,
circuit 1050 (LG/VT) and ground. Yes
GO to
A2 .
No
REPAIR circuit 1050 (LG/VT) Klj . 2 ba
112003 Mustang Workshop Manual
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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
112003 Mustang Workshop Manual
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