What does it mean?
B2384 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Horn Switch Output Circuit Low .
Symptoms
- The audio does not mute or drop in volume when reverse gear is selected
- Parking aid tones are hard to hear over the music
- The audio mutes permanently and will not come back in any gear
- Parking sensors work correctly but the audible warning is masked
- The problem started right after a radio or amplifier was changed
Likely causes
- Open or shorted mute request wire between the parking aid module and the audio unit
- Corroded or backed out terminal at the radio harness connector
- Failed output in the parking aid module that drives the mute line
- Harness damage behind the centre console from a previous audio or accessory installation
- Aftermarket head unit or adapter harness that does not support the factory mute input
- Water damage in the rear loom feeding the reverse aid module
- Faulty mute input stage inside the audio unit
How to fix it
- Confirm the reverse parking aid itself is working and that reverse gear is being recognised by the modules
- With reverse selected, measure the mute request line at the audio connector and compare it with the specified state change
- If the line never changes, test the same pin at the parking aid module to decide which side of the circuit is at fault
- Check continuity and insulation to ground on the mute wire between the two modules
- Inspect the radio connector for spread or pushed back terminals, especially where the unit has been removed before
- Where an aftermarket unit or adapter is fitted, verify the mute wire is actually connected and configured
- Replace whichever module fails to drive or read the line once the wiring has been proven good