Code
B128B
LAND ROVER
B — Body
Speaker 14
Views:
UK: 5
EN: 15
RU: 6
AI status
Completed
Completed
100%
Causes
- Open circuit in speaker wiring or connector
- Short to ground or battery on speaker output
- High resistance connection (corroded connector, broken wire)
- Failed speaker element (voice coil short or open)
- Faulty amplifier/infotainment module output stage or internal connector
- Water ingress or physical damage to speaker or connector
Symptoms
- No sound from one speaker (speaker 14)
- Distorted, intermittent or low volume from that speaker
- Clicking, popping or buzzing noises from that location
- Audio system reports speaker fault or mutes outputs
- DTC present in infotainment or body control module
What to check
- Obtain wiring diagram and identify location of speaker 14 and associated amplifier/module
- Use diagnostic tool to read/record DTC and any related audio module faults
- Perform module-built in speaker test/actuation (if supported)
- Inspect speaker and connector for corrosion, water, or physical damage
- Visually inspect wiring along harness runs (doors, pillars, trunk) for chafing or breaks
- Backprobe amplifier/speaker connector with ignition and audio on to observe signal
Signal parameters
- Typical passenger-car speaker impedance: 4–8 Ω (DC resistance usually ~2–7 Ω)
- Expected AC audio signal: variable, up to several volts peak-to-peak during playback
- Amplifier supply: nominal ~12 V battery supply; BTL outputs may have no DC offset when idle
- Open-circuit: infinite Ω between speaker terminals
- Short-to-ground/power: near 0 Ω to chassis or battery
Diagnostic algorithm
- Confirm vehicle and DTC: record freeze frame and any related codes, then reproduce the symptom
- Identify speaker 14 location from factory wiring diagram and note amplifier/head unit channel assignment
- Perform module speaker self-test: if module detects fault again, note how it reports the fault (open/short/high resistance)
- Visually inspect speaker and connector for water, corrosion, or damage; repair or reseal as needed
- Disconnect speaker 14 at the speaker and measure DC resistance across speaker terminals with a multimeter; acceptable DC resistance depends on speaker rating (commonly 2–7 Ω). If open or extreme value, replace speaker
- If speaker resistance is normal, backprobe amplifier output at the connector with audio playing and measure AC waveform or voltage. No signal indicates amplifier/module or wiring open. Distorted waveform or DC offset indicates amplifier fault
- Check continuity between amplifier output and speaker connector; repair any opens/shorts found. Check for short to ground/power between signal and chassis or battery
- If available, swap speaker 14 with a known good speaker (or swap amplifier channels) to determine whether the fault follows the speaker or the channel
- If wiring and speaker are good but fault remains, suspect amplifier/head unit. Check for software updates or module reprogramming and replace module or amplifier only after confirming
- Clear DTCs, perform functional test (play test tone/road test) and confirm fault does not return
Likely causes
- Damaged speaker wiring at door/hatch hinge or body harness
- Corroded or disconnected speaker connector at speaker or amp
- Defective speaker (burned voice coil)
- Faulty amplifier channel in the head unit or external amp
Fault status
Status
Audio module detected abnormal condition on speaker 14 circuit (open/short/high resistance or speaker failure).
Repair difficulty: Medium
Diagnostic time: 0.5-2.5 hours
Similar codes
Workshop Manuals
Repair manuals for LAND ROVER
3
Land Rover Defender 300Tdi — Workshop Manual (1996 model year)
Workshop ManualLand Rover Defender Workshop Manual Supplement & Body Repair Manual (1999 & 2002 MY)
Workshop ManualLand Rover Range Rover — Electrical Library (LRL 0453ENG, 2002)
Workshop ManualYour experience will help others
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