Ford 2003 Mustang Workshop Manual page 3407

Turn on the audio unit.
Is the sound quality OK?
F11 CHECK THE AUDIO UNIT
Key in OFF position.
Substitute the affected audio unit with a known good component.
Key in ON position.
Turn on the audio unit.
Is the sound quality OK?
PINPOINT TEST G: POOR QUALITY SOUND FROM ALL SPEAKERS
Test Step
G1 CHECK POOR SOUND QUALITY IN
ALL SPEAKERS
Key in ON position.
Turn on the audio unit.
Carry out the speaker walk-around test
by pressing preset buttons 3 and 6
simultaneously.
Is there poor quality or distortion in
all speakers?
PINPOINT TEST H: THE SUBWOOFER IS INOPERATIVE
H1 CHECK THE SUBWOOFER OPERATION
Key in ON position.
Turn on the audio unit and listen for correct subwoofer operation.
Are all subwoofers inoperative?
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 Pinpoint Test F
Test Step
system for normal
operation.
No
GO to
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
for normal
operation.
Result / Action to Take
.
Result / Action to
Yes
GO to
No
For convertible,
GO to
For coupe, GO to
H6 .
F7 .
Take
H16 .
H2 .