2003 FORD MUSTANG wiring diagram

DIAGNOSIS AND TESTING
Climate Control System
Refer to Wiring Diagrams Cell
54 , Air Conditioner/Heater for schematic and connector information.
SECTION 412-
00: Climate Control System - General Information 2003 Mustang Workshop Manual Special Tool(s)
Connector, Refrigerant
Pressure Line
412-
093 (T94P-19623- E) Set, A/C Fittings
412-
DS028 (014- 00333, D93L-
19703- B) or equivalent Vacuum Pump Kit
416-
D002 (D95L-7559- A) or
equivalent Breakout Box, EEC-V Control
System
418- 049 (014-00950, T94L-50-
EEC- V) Worldwide Diagnostic System
(WDS)
418-
F224,
New Generation STAR (NGS)
Tester
418- F052, or equivalent
diagnostic tool Pressure Test Kit
014-
R1072 or equivalent 77 III Automotive Meter
105-
R0056 or equivalent Klj . 1 ba
412003 Mustang Workshop Manual
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DIAGNOSIS AND TESTING
Instrument Cluster and Panel Illumination
Refer to Wiring Diagrams Cell
71 , Instrument Illumination for schematic and connector information.
Inspection and Verification
NOTE: A new instrument cluster must be reconfigured. Refer to Section 418 - 01 .
NOTE: The instrument panel dimmer switch is a part of the headlamp switch.
1. Verify the customer concern.
2. Visually inspect for obvious signs of electrical damage.
3. If the fault is not visually evident, determine the symptom and proceed to the Symptom Chart.
Symptom Chart SECTION 413-
00: Instrument Cluster and Panel Illumination 2003 Mustang Workshop Manual Special Tool(s)
73III Automotive Meter
105-
R0057 or equivalent
Visual Inspection Chart Electrical
z
Central junction box (CJB) fuses:
„5 (15A)
„ 21 (5A)
„ 34 (20A)
„ 37 (5A)
„ 32 (15A)
„ 27 (20A)
z Circuitry
z Damaged switch
Symptom Chart Condition
Possible Sources Action
z The control illumination is
inoperative z
Central junction box
(CJB) fuse 37 (5A).
z Circuitry.
z Headlamp switch. z
Go To Pinpoint Test A .
z The instrument cluster
illumination is inoperative z
Circuitry.
z Instrument cluster. z
Go To Pinpoint Test B . Klj . 1 ba
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Pinpoint Tests
PINPOINT TEST A: THE CONTROL ILLUMINATION IS INOPERATIVE
PINPOINT TEST B: THE INSTRUMENT CLUSTER ILLUMINATION IS
INOPERATIVE z
Bulb(s).
z The climate control
illumination is inoperative z
Circuitry.
z Bulb(s). z
Go To Pinpoint Test C .
z The audio system
illumination is inoperative z
Circuitry.
z Audio unit. z
Go To Pinpoint Test D .
z A single illumination source
is inoperative z
Circuitry.
z Switch. z
Go To Pinpoint Test E .
Test Step Result / Action to Take
A1 CHECK PARKING LAMPS
z
Place the headlamp switch in the ON
position.
z Are the exterior lamps on? Yes
Place the headlamp switch in the OFF position.
GO to
A2 .
No
REFER to Section 417 - 01 .
A2 CHECK HEADLAMP SWITCH
z
Key in OFF position.
z Carry out the headlamp switch
components test;
Refer to Wiring Diagrams Cell 149 for
schematic and connector information.
.
z Is the headlamp switch OK? Yes
RECONNECT the headlamp switch. GO to
A3 .
No
INSTALL a new headlamp switch. REFER to
Section 417 - 01 . TEST the system for normal
operation. A3 CHECK CIRCUIT 1045 (DB/WH)
z
Place the headlamp switch in the ON
position.
z Rotate the instrument panel dimmer
switch to the full illumination position.
z Measure voltage between central
junction box (CJB) fuse 37 (5A) and
ground.
z Is the voltage greater than 10 volts? Yes
REPAIR circuit 19 (LB/RD). TEST the system for
normal operation.
No
REPAIR circuit 1045 (DB/WH). TEST the system
for normal operation.
Test Step Result / Action to Take
B1 CHECK VOLTAGE TO INSTRUMENT CLUSTER
ILLUMINATION z
Disconnect: Instrument Cluster .
z Place the headlamp switch in the ON position.
z Rotate the instrument panel dimmer switch to the full Yes
GO to
B2 . Klj . 2 ba
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DIAGNOSIS AND TESTING
Instrument Cluster
Refer to Wiring Diagrams Cell
60 , Instrument Cluster for schematic and connector information.
Principles of Operation
NOTE: A new instrument cluster must be reconfigured. Refer to Section 418 - 01 .
The instrument cluster is a hybrid electronic cluster (HEC). The instrument cluster uses both hardwired
and the standard corporate protocol (SCP) communication network to transmit and receive
information. As a technician it is very important to understand:
zwhere the input originates from.
z all information necessary in order for a feature to operate.
z which module(s) receive(s) the input or command message.
z does the module which received the input control the output of the feature, or does it output a
message over the SCP network to another module?
z which module controls the output of the feature.
The instrument cluster carries out a display prove- out to verify that the warning/indicator miniature
bulbs for monitored systems are functioning correctly. When the ignition switch is in the ON position
with the engine off, the following warning indicators will prove out:
zanti- lock brake (ABS) warning indicator
SECTION 413-
01: Instrument Cluster 2003 Mustang Workshop Manual Special Tool(s)
Worldwide Diagnostic System
(WDS)
418-
F224,
New Generation STAR (NGS)
Tester
418- F052, or equivalent
diagnostic tool Instrument Gauge System
Tester
014-
R1063 or equivalent 73III Automotive Meter
105-
R0057 or equivalent Klj . 1 ba
412003 Mustang Workshop Manual
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DIAGNOSIS AND TESTING
Horn
Refer to Wiring Diagrams Cell
44 , Horns/Cigar Lighter for schematic and connector information.
Inspection and Verification 1. Verify the customer concern by operating the horn (13832).
2. Visually inspect for obvious signs of mechanical and electrical damage.
3. If fault is not visually evident, determine the symptom and proceed to Symptom Chart.
Symptom Chart SECTION 413-
06: Horn 2003 Mustang Workshop Manual Special Tool(s)
73 Digital Multimeter or
equivalent
105-
R0051
Visual Inspection Chart Mechanical Electrical
z
Damaged horns
z Damaged horn switch
z Damaged air bag sliding contact
(14A664) z
Blown battery junction box (BJB) Fuse Horn
Relay (20A)
z Damaged wiring harness
z Damaged connections
z Damaged horn relay
z Damaged horn switch
Symptom Chart Condition
Possible Sources Action
z The horn does not
sound z
BJB Fuse Horn Relay (20A).
z Circuitry.
z Horn relay.
z Air bag sliding contact.
z Horn switch.
z Horns. z
GO to
Pinpoint Test A .
z The horn sounds
continuously z
Circuitry.
z Horn relay.
z Remote entry system (generic
electronic module [GEM]) z
GO to
Pinpoint Test B . Klj . 1 ba
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Pinpoint Tests
PINPOINT TEST A: THE HORN DOES NOT SOUND module.
z Horn switch. Test Step Result / Action to
Take A1 CHECK POWER SUPPLY TO HORN RELAY
z
Disconnect: Horn Relay.
z Measure the voltage between the horn relay connector Pin 2,
Circuit 460 (YE/LB), harness side and ground; and between the
horn relay connector Pin 5, Circuit 460 (YE/LB), harness side and
ground.
z Are the voltages greater than 10 volts? Yes
GO to
A2 .
No
REPAIR the circuit in
question. TEST the
system for normal
operation. A2 CHECK HORN RELAY
z
Check the horn relay; refer to Wiring Diagrams Cell 149.
z Is the horn relay OK? Yes
GO to
A3 .
No
INSTALL a new horn
relay. TEST the
system for normal
operation. A3 CHECK HORN SWITCH SIGNAL TO HORN RELAY
z
Measure the resistance between horn relay connector Pin 1,
Circuit 6 (YE/LG), harness side and ground under the following
conditions:
Horn Switch Position Horn Switch Position Resistance
Pressed Less than 5 ohms
Released Greater than 10,000 ohms Yes
GO to
A4 .
No
GO to A5 . Klj . 2 ba
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PINPOINT TEST B: THE HORN SOUNDS CONTINUOUSLY connector Pin 3, Circuit 6 (component side), and air bag sliding
contact C218a Pin 2, Circuit 6 (component side).
z Is the resistance less than 5 ohms? No
INSTALL a new air
bag sliding contact.
REFER to
Section 501 - 20B . TEST the
system for normal
operation. A7 CHECK THE STEERING WHEEL SWITCH HARNESS
z
Inspect the steering wheel switch harness for chafing, opens or
possible short to ground.
z Is the steering wheel switch harness OK? Yes
INSTALL a new horn
switch. REFER to
Switch
— Horn . TEST
the system for normal
operation.
No
INSTALL a new
steering wheel switch
harness. TEST the
system for normal
operation. Test Step Result / Action to Take
B1 CHECK HORN CIRCUIT 1 (DB)
z
Key in OFF position.
z Disconnect: Horn Relay.
z Does the horn continue to sound? Yes
REPAIR Circuit 1 (DB) for short to battery. TEST
the system for normal operation.
No
GO to
B2 .
B2 CHECK HORN RELAY
z
Check the horn relay; refer to Wiring
Diagrams Cell 149.
z Is the horn relay OK? Yes
REINSTALL the horn relay. GO to
B3 .
No
INSTALL a new horn relay. TEST the system for
normal operation. B3 CHECK CIRCUIT 6 (YE/LG)
z
Disconnect: Air Bag Sliding Contact
C218a .
z Does the horn continue to sound? Yes
GO to
B4 .
No
RECONNECT the air bag sliding contact. GO to
B5 .
B4 CHECK GEM INPUT
z
Disconnect: GEM C201e. Yes Klj . 4 ba
52003 Mustang Workshop Manual
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DIAGNOSIS AND TESTING
Gauges And Warning Devices
Refer to Wiring Diagrams Cell
59 , Generic Electronic Module for schematic and connector
information.
Refer to Wiring Diagrams Cell 60 , Instrument Cluster for schematic and connector information.
Refer to Wiring Diagrams Cell 66 , Warning Chime for schematic and connector information.
Principles of Operation
Key- In-Ignition Warning Chime
The key- in-ignition warning chime activates when the generic electronic module (GEM) detects the
ignition switch circuits are in the OFF or ACC states and when the GEM detects the driver door is ajar
from the driver door ajar circuits. Refer to the Chime Duration Table in this section for audible output,
duration time, and priority ratings.
Airbag Warning Chime
The airbag warning chime activates when the GEM detects the ignition switch circuits are in the RUN
state and when the GEM detects a chime is requested from the airbag system circuit. Refer to the
Chime Duration Table for audible output, duration time, and priority ratings.
Door Ajar Warning Chime
The door ajar warning chime activates when the GEM detects the ignition switch circuits are in the
RUN state and when the GEM detects the driver or passenger door is ajar from the driver and
passenger door ajar circuits. Refer to the Chime Duration Table in this section for audible output,
duration time, and priority ratings.
Headlamps Left on Warning Chime
The headlamps left on warning chime activates when the GEM detects the ignition switch circuits are
in the KEYOUT state, when the GEM detects the driver door is ajar from the driver door ajar circuit, SECTION 413-
09: Warning Devices 2003 Mustang Workshop Manual Special Tool(s)
73III Automotive Meter
105-
R0057 or equivalent Worldwide Diagnostic System
(WDS)
418-
F224,
New Generation STAR (NGS)
Tester
418- F048, or equivalent
diagnostic tool Klj . 1 ba
202003 Mustang Workshop Manual
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