What does it mean?
B1477 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Channel 5 Audio Speaker Output Circuit Open .
Symptoms
- The channel 5 speaker is completely silent while the rest of the system plays
- Fader and balance no longer bring sound to that position
- Sound may return for a moment when the trim or door is moved if a broken strand touches
- The system sounds unbalanced, and detail or fill from that position is missing
- Code returns at every ignition cycle
Likely causes
- Speaker connector unplugged or only half seated after trim, seat or rear panel work
- Broken conductor where the loom flexes, such as a door jamb boot or a tailgate hinge
- Open voice coil after long-term overdriving, corrosion or age
- Corroded spade terminal that no longer grips the speaker tab
- Terminal backed out of the amplifier or head unit connector
- Channel never connected after a non-standard audio installation
- Amplifier output stage failed open on channel 5
How to fix it
- Identify the silent position with fader and balance
- Remove the trim and check that the connector is fully latched and the terminals grip the tabs
- Measure the speaker at its own terminals; an infinite reading means an open voice coil
- Check continuity of each output wire between the amplifier and the speaker connector to find the break
- Flex the loom at each bend point while measuring, since breaks form where it moves
- Inspect the amplifier connector for an unlocked or pushed-out terminal and seat it properly
- Repair the wire with a soldered or correctly crimped joint and protect it where it flexes
- Replace the speaker if the coil is open, then clear the code and verify with a fader sweep