Classify the audio complaint
Factory service information separates display/no-sound, display-dead/speakers-working, reception, playback-device and channel complaints.
BODY ELECTRICAL · 2002
2002 Firebird Radio / No Sound Diagnostic Start
A dead display, normal display with no sound, poor reception and one-channel faults belong on different audio branches.
APPLICATION: 2002 Pontiac Firebird / Formula / Trans Am with the factory system described. Match options and installed hardware before applying a circuit path.
Check modifications immediately
Aftermarket head units, amplifiers, alarm wiring and speaker changes can alter the factory circuit. Diagnose the car that exists today.
Separate power/control from audio output
Verify the radio state and applicable feeds, then isolate speaker/amplifier/output paths based on which channels and functions remain.
DO NOT CONDEMN THE RADIO YET
A no-sound complaint can live downstream of a functioning head unit. Prove the failed branch before replacement.
FPV RULE
OBSERVE → MEASURE → ISOLATE → PROVE → REPAIR → VERIFY. A symptom is a starting point, not a parts verdict.