FORD MUSTANG 2003 Workshop Manual

DIAGNOSIS AND TESTING
Audio System
Refer to Wiring Diagrams Cell
130 , Radio for schematic and connector information.
Inspection and Verification 1. Verify the customer concern by operating the electronic audio system with the engine running.
2. Visually inspect the following for obvious signs of mechanical and electrical damage.
3. If the concern remains and the fault is not detected, proceed to the Symptom Chart to continue diagnostics.
Symptom Chart SECTION 415-
00: Entertainment System — General Information 2003 Mustang Workshop Manual Special Tool(s)
73III Automotive Meter
105-
R0057 or equivalent
Visual Inspection Chart Mechanical Electrical
z
Audio unit
z Antenna or antenna cable
z Speakers mounting/speaker cones
z Radio ignition interference capacitor, radio frequency
interference suppression bond or radio receiver hood bonding
strap cleanliness z
Battery junction box
(BJB) fuses:
„3 (40A)
„ 4 (40A)
„ 6 (40A)
z Central junction box
(CJB) fuses:
„6 (20A)
„ 27 (25A)
„ 32 (15A)
z Ignition switch
z Circuitry
z Audio unit
Symptom Chart Condition
Possible Sources Action
z The audio unit is
inoperative/does not operate z
Central
junction box z
Go To Pinpoint Test A . Klj . 1 ba
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correctly
(CJB) fuses:
„6
(20A).
„ 27
(25A).
„ 32
(15A).
z Battery
junction box
(BJB) fuses:
„3
(40A).
„ 4
(40A).
„ 6
(40A).
z Circuitry.
z Audio unit.
z Ignition
switch.
z Audio unit display blank —
audio unit operates z
Audio unit. zREMOVE the audio
unit and SEND it to
an authorized Ford
audio system repair
facility. TEST the
system for normal
operation.
z Tape player only inoperative zAudio unit. zREMOVE the audio
unit and SEND it to
an authorized Ford
audio system repair
facility. TEST the
system for normal
operation.
z Poor reception zAntenna
connections.
z Antenna
cable.
z Noise
suppression
equipment.
z Audio unit.
z Generator.
z Ignition
system. z
Go To Pinpoint Test B .
z Poor reception — FM only zFM signal out
of range. z
INFORM customer
of methods for
obtaining best
reception.
z Continuous SEEK/SCAN in
AM/FM z
Antenna.
z Antenna
connections.
z Audio unit. z
Go To Pinpoint Test C .
z No sound from one or more of
the speakers — not all speakers z
Speaker(s).
z Circuitry.
z Audio unit.
z Subwoofer
amplifier. z
Go To Pinpoint Test D .
z No sound from all of the zAudio unit. zGo To Pinpoint Test Klj . 2 ba
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Pinpoint Tests speakers
zSubwoofer
amplifier.
z Circuitry. E .
z Poor quality sound from one or
more speakers (not all
speakers) z
Speaker(s).
z Circuitry.
z Audio unit.
z Subwoofer
amplifier. z
Go To Pinpoint Test F .
z Poor quality sound from all
speakers z
Audio unit.
z Speaker(s).
z Circuitry. z
Go To Pinpoint Test G .
z The subwoofer is inoperative zSubwoofer.
z Subwoofer
amplifier.
z Circuitry. z
Go To Pinpoint Test H .
z Loud popping when cycling the
ignition switch z
Audio unit.
z Circuitry. z
Go To Pinpoint Test I .
z One or more audio control
buttons (such as volume, seek,
tune and scan) are not
functional in either radio, tape,
or CD mode or all modes z
Audio unit. zREMOVE the audio
unit and SEND it to
an authorized Ford
audio system repair
facility. TEST the
system for normal
operation.
z When the headlamp switch is in
park or headlamp position and
the ignition switch is in the RUN
or ACC position, the audio unit
back lighting is inoperative — all
other I/P lighting functions are
normal z
Circuitry.
z Audio unit. z
REFER to Section 413 - 00 .
z The audio unit has two items
that can be dimmed— the audio
unit display and the control
buttons; one dims and the other
does not z
Audio unit. zREMOVE the audio
unit and SEND it to
an authorized Ford
audio system repair
facility. TEST the
system for normal
operation.
z Irregular operation of display
and indicator LEDs z
Audio unit. zREMOVE the audio
unit and SEND it to
an authorized Ford
audio system repair
facility. TEST the
system for normal
operation.
z Response time between
pressing any of the audio
control buttons and system
response is more than two
seconds z
Audio unit. zREMOVE the audio
unit and SEND it to
an authorized Ford
audio system repair
facility. TEST the
system for normal
operation. Klj . 3 ba
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PINPOINT TEST A: THE AUDIO UNIT IS INOPERATIVE/DOES NOT
OPERATE CORRECTLY
Test Step Result / Action to
Take A1 CHECK OPERATION OF THE AUDIO UNIT
z
Key in ON position.
z Turn on the audio unit.
z Is the audio unit display illuminated? Yes
GO to
A2 .
No
GO to A4 .
A2 CHECK FOR SOUND COMING FROM THE SPEAKERS
z
Verify that sound is coming from all the speakers.
z Is there sound coming from all the speakers? Yes
GO to
A3 .
No
GO to Pinpoint Test C .
A3 CHECK THE AUDIO UNIT CONTROLS AND FEATURES
z
Refer to the owner literature for audio system controls.
z Verify that the controls and features operate correctly.
z Do the controls and features operate correctly? Yes
System operation is
normal at this time.
No
REMOVE the audio
unit and SEND it to
an authorized Ford
audio system facility.
TEST the system for
normal operation.
A4 CHECK VOLTAGE AT THE AUDIO UNIT
z
Key in OFF position.
z Disconnect: Audio Unit C290b.
z Key in ON position.
z Measure the voltage between the audio unit C290b pin 10, circuit
1002 (BK/PK), harness side and ground, and between the audio
unit C290b pin 9, circuit 828 (VT/LB), harness side and ground.
z Are the voltages greater than 10 volts? Yes
GO to
A5 .
No
REPAIR the circuit
(s) in question. TEST
the system for
normal operation. A5 CHECK THE GROUND CIRCUITS TO THE AUDIO UNIT
z
Key in OFF position.
z Measure the resistance between the audio unit C290b pin 2, circuit
1205 (BK), harness side and ground; and between the audio unit
C290b pin 11, circuit 694 (BK/LG), harness side and ground; and
between the audio unit C290b pin 16, circuit 694 (BK/LG), harness
side and ground Yes
REMOVE the audio
unit and SEND it to
an authorized Ford
audio system repair
facility. TEST the Klj . 4 ba
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PINPOINT TEST B: POOR RECEPTION z
Are the resistances less than 5 ohms? system for normal
operation.
No
REPAIR the circuit
(s) in question. TEST
the system for
normal operation.
Test Step Result / Action to Take
B1 CHECK ANTENNA CABLE
CONNECTIONS z
Key in OFF position.
z Check the antenna connections
including the extension cable.
z Check to make sure the antenna is
securely mounted to the vehicle body
at ground points.
z Are the connections clean, secure,
and in metal- to-metal contact? Yes
GO to
B2 .
No
CLEAN and SECURE the antenna connections
as necessary. TEST the system for normal
operation. B2 CHECK SUPPRESSION
EQUIPMENT/MOUNTING AND
CONNECTING CIRCUITS z
Check all necessary suppression
equipment and the radio frequency
interference suppression bond. Refer
to Section 415 - 01 .
z Check the radio receiver hood bonding
strap and the body- to-chassis straps
for integrity, cleanliness, and metal- to-
metal contact.
z NOTE: The capacitor mounting points
are used to complete the electrical
circuit and must be mounted securely
to clean surfaces.
z Check the mounting and connecting
circuits of the radio ignition interference
capacitor for integrity, cleanliness, and
metal- to-metal contact.
z Are the connections clean, secure,
and in metal- to-metal contact? Yes
GO to
B3 .
No
CLEAN, SECURE, or INSTALL new suppression
equipment as necessary. TEST the system for
normal operation. B3 CHECK RADIO IGNITION
INTERFERENCE CAPACITOR z
Check the operation of the radio
ignition interference capacitor by
substituting it with a known good
component.
z Key in START position.
z Turn the audio unit on and check the
radio reception. Yes
INSTALL a new radio ignition interference
capacitor. TEST the system for normal operation.
No
GO to
B4 . Klj . 5 ba
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z
Is the noise eliminated? B4 CHECK GENERATOR
z
Key in OFF position.
z Check the generator by disconnecting
the wiring from the voltage regulator.
z Key in START position.
z Turn on the audio unit and check the
radio reception.
z Is the noise eliminated? Yes
INSTALL a new generator. REFER to
Section 414 - 02 . TEST the system for normal operation.
No
GO to B5 .
B5 CHECK IGNITION CIRCUITS
z
Key in OFF position.
z Check the ignition circuits for correct
routing, grounding, and integrity of
connections.
z Are the ignition components OK? Yes
GO to
B6 .
No
REPAIR the ignition system as necessary. TEST
the system for normal operation. B6 SUBSTITUTE ANTENNA
z
Substitute a known good antenna.
Ground the antenna base to an
unpainted metal surface on the vehicle.
z Key in START position.
z Verify the operation of the audio unit.
z Is the noise eliminated? Yes
INSTALL a new antenna. TEST the system for
normal operation.
No
GO to
B7 .
B7 SUBSTITUTE ANTENNA CABLE
z
Key in OFF position.
z Substitute a known good antenna
cable.
z Key in START position.
z Verify the operation of the audio unit.
z Is the noise eliminated? Yes
INSTALL a new antenna cable. TEST the system
for normal operation.
No
GO to
B8 .
B8 SUBSTITUTE AUDIO UNIT
z
Key in OFF position.
z Substitute a known good audio unit.
z Key in START position.
z Verify the operation of the audio unit.
z Is the noise eliminated? Yes
REMOVE the audio unit and SEND it to an
authorized Ford audio system repair facility.
TEST the system for normal operation.
No
GO to
B9 .
B9 SUBSTITUTE SUBWOOFER
AMPLIFIER z
Key in OFF position.
z Substitute a known good subwoofer
amplifier.
z Key in START position.
z Verify the operation of the audio unit.
z Is the noise eliminated? Yes
REMOVE the subwoofer amplifier and SEND it to
an authorized Ford audio system repair facility.
TEST the system for normal operation.
No
GO to
B10 .
B10 REPOSITION COMPONENTS
z
Key in OFF position.
z Determine if the noise can be
eliminated by repositioning the antenna
cable, speaker circuits, or audio unit
power feed circuits away from other
circuits or brackets.
z Key in START position.
z Verify the operation of the audio unit. Yes
Permanently REPOSITION the components as
needed. TEST the system for normal operation.
No
GROUND various parts (for example, engine,
fenders, quarter panels, stone deflectors, body
sheet metal) of the vehicle to the frame using a Klj . 6 ba
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PINPOINT TEST C: CONTINUOUS SEEK/SCAN IN AM/FM
PINPOINT TEST D: NO SOUND FROM ONE OR MORE OF THE
SPEAKERS —
NOT ALL SPEAKERS z
Is the noise eliminated? jumper cable. When noise is eliminated,
PROVIDE a permanent ground where
necessary. TEST the system for normal
operation.
Test Step Result / Action to Take
C1 CHECK OPERATION OF THE
SEEK/SCAN FUNCTIONS z
Key in ON position.
z Operate the SEEK/SCAN functions
with the audio unit in both AM and FM
tuner modes.
z Do the SEEK/SCAN functions
search continuously? Yes
GO to
C2 .
No
The system is OK. C2 CHECK ANTENNA FOR DAMAGE
z
Key in OFF position.
z Disconnect: Antenna Lead Terminal.
z Measure the resistance between the
antenna cable lead terminal and the
end of the antenna grid wire.
z Is the resistance less than 8 ohms? Yes
GO to
C3 .
No
REPAIR the antenna. REFER to Section 415 - 02
C3 SUBSTITUTE ANTENNA EXTENSION
CABLE z
Substitute a known good antenna
cable between the audio unit and the
antenna.
z Key in START position.
z Check the operation of the audio unit.
z Is the noise eliminated? Yes
INSTALL a new antenna extension cable. REFER
to
Section 415 - 02 . TEST the system for normal
operation.
No
REINSTALL the original cable. REMOVE the
audio unit and SEND it to an authorized Ford
audio system repair facility. TEST the system for
normal operation. Test Step Result / Action to
Take D1 CHECK FOR SOUND
z
Key in ON position.
z Turn on the audio unit.
z Are all speakers without sound? Yes
GO to
Pinpoint Test E .
No
For convertible,
GO to D2 .
For coupe, GO to
D4 . Klj . 7 ba
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For Mach 1000
subwoofer
speakers,GO to
D8
.
D2 CHECK CIRCUITS BETWEEN THE AFFECTED SPEAKER(S) AND
SUBWOOFER AMPLIFIERS z
Disconnect: Subwoofer Amplifier C4108a.
z Disconnect: Subwoofer Amplifier C4109b.
z Disconnect: Affected Speaker(s).
z Measure the resistance between the subwoofer amplifier and the
affected speaker(s) and between the subwoofer amplifier and ground
as follows:
z Are the resistances less than 5 ohms between the subwoofer
amplifier and the affected speaker(s) and greater than 10,000
ohms between the subwoofer amplifier and ground? Speaker Circuits Affected Speaker Pin Subwoofer Amplifier Pin Circuit
RF 1 (convertible only) LH 7 822 (BK/LG)
RF 2 (convertible only) LH 8 287 (BK/WH)
LF 1 (convertible only) LH 7 822 (BK/LG)
LF 2 (convertible only) LH 8 287 (BK/WH)
RR 1 RH 7 822 (BK/LG)
RR 2 RH 8 287 (BK/WH)
LR 1 RH 7 822 (BK/LG)
LR 2 RH 8 287 (BK/WH) Yes
GO to
D3 .
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation. D3 CHECK CIRCUITS BETWEEN THE AUDIO UNIT AND THE
SUBWOOFER AMPLIFIERS z
Disconnect: Audio Unit C290b.
z Disconnect: Subwoofer Amplifier C4108a.
z Disconnect: Subwoofer Amplifier C4109b.
z Measure the resistance between the subwoofer amplifier and the
audio unit C290b and between the subwoofer amplifier and ground
as follows:
z Are the resistances less than 5 ohms between the subwoofer
amplifier and the audio unit and greater than 10,000 ohms
between the subwoofer amplifier and ground? Speaker Circuits Audio Unit C290b Pin Subwoofer Amplifier Pin Circuit
2 LH 5 167 (BN/OG)
6 RH 5 169 (LG/BK)
1 LH 6 168 (RD/BK)
5 RH 6 172 (LB/RD) Yes
GO to
D6 .
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation. D4 CHECK CIRCUITS BETWEEN THE AFFECTED SPEAKER(S) AND
SUBWOOFER AMPLIFIER z
Disconnect: Subwoofer Amplifier C4109b.
z Disconnect: Affected Speaker(s).
z Measure the resistance between the subwoofer amplifier and the Yes
GO to
D5 . Klj . 8 ba
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affected speaker(s) and between the subwoofer amplifier and ground
as follows:
z Are the resistances less than 5 ohms between the subwoofer
amplifier and affected speaker(s) and greater than 10,000 ohms
between the subwoofer amplifier and ground? Speaker Circuits Affected Speaker Pin Subwoofer Amplifier Pin Circuit
RR 1 7 822 (BK/LG)
RR 2 8 287 (BK/WH)
LR 1 7 822 (BK/LG)
LR 2 8 287 (BK/WH) No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation.
D5 CHECK CIRCUITS BETWEEN THE AUDIO UNIT AND THE
SUBWOOFER AMPLIFIER z
Disconnect: Audio Unit C290b.
z Disconnect: Subwoofer Amplifier C4109b.
z Measure the resistance between the subwoofer amplifier C4109b pin
5, circuit 169 (LG/BK), harness side and the audio unit C290a pin 6,
circuit 169 (LG/BK), harness side and between the subwoofer
amplifier C4109b pin 5, circuit 169 (LG/BK), harness side and
ground; and between the subwoofer amplifier C4109b pin 6, circuit
172 (LB/RD), harness side and the audio unit C290a pin 5, circuit
172 (LB/RD), harness side and between the subwoofer amplifier
C4109b pin 6, circuit 172 (LB/RD), harness side and ground.
z Are the resistances less than 5 ohms between the subwoofer
amplifier and the audio unit and greater than 10,000 ohms
between the subwoofer amplifier and ground? Yes
GO to
D6 .
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation. D6 CHECK SPEAKER(S)
z
Key in OFF position.
z Substitute the affected speaker with a known good component.
z Key in ON position.
z Turn on the audio unit.
z Is the affected speaker(s) operational? Yes
INSTALL a new
speaker. TEST the
system for normal
operation.
No
GO to
D7 .
D7 CHECK THE AUDIO UNIT
z
Key in OFF position.
z Substitute the affected audio unit with a known good component.
z Key in ON position.
z Turn on the audio unit.
z Is the affected speaker(s) operational? Yes
SEND the audio
unit to an
authorized Ford
audio system
repair facility.
TEST the system
for normal
operation.
No
REMOVE the
subwoofer
amplifier and
SEND it to an
authorized Ford
audio system
repair facility.
TEST the system Klj . 9 ba
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for normal
operation.
D8 CHECK FOR POWER TO THE AFFECTED SUBWOOFER
AMPLIFIER z
Key in OFF position.
z Disconnect: Mach 1000 Affected Subwoofer Amplifier.
z Measure the voltage between affected subwoofer amplifier pin 5,
circuit 828 (VT/LB) (left amplifiers) and ground, or between pin 5,
circuit 829 (WH/VT) (right amplifiers) and ground.
z Is the voltage greater than 10 volts? Yes
GO to
D9 .
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation. D9 CHECK FOR GROUND TO THE AFFECTED SUBWOOFER
AMPLIFIER z
NOTE: Ground circuit 694 is located in the same cavity in all four
subwoofer amplifiers.
z Measure the resistance between affected subwoofer amplifier pin 2,
circuit 694 (BK/LG) and ground.
z Is the resistance less than 5 ohms? Yes
GO to
D10 .
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation. D10 CHECK FOR AN AUDIO SIGNAL TO THE AFFECTED
SUBWOOFER AMPLIFIER z
Key in ON position.
z NOTE: Audio signal circuits 169 and 172 are located in the same
cavity on all four subwoofer amplifiers.
z Turn on the audio unit and check for a fluctuating AC voltage
between affected subwoofer amplifier pin 8, circuit 172 (LB/RD) and
pin 7, circuit 169 (LG/BK). Yes
GO to
D12 .
No
GO to D11 . Klj . 10 ba
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