B128C

Code

LAND ROVER B — Body

Speaker 15

Brand: LAND ROVER

Type: B — Body

Views: UK: 17 EN: 41 RU: 22

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Page language: EN

Causes

Open or short circuit in speaker 15 wiring
Failed speaker (voice coil open or shorted)
Corroded or loose connector at speaker or amplifier
Faulty amplifier/audio module output channel
Blown fuse or poor ground for the audio system
Water ingress or physical damage at the speaker

Symptoms

No sound from the specific speaker labeled '15'
Distorted or intermittent audio from that speaker
Reduced overall audio quality or imbalance
Audio system warnings or fault messages in infotainment
Problem persists after changing source/input (radio, phone, media)

What to check

Confirm customer complaint and identify which physical speaker is '15' using vehicle-specific speaker location chart
Scan all modules and read stored DTCs and freeze frame data
Visually inspect speaker, grille and surrounding area for water or damage
Check speaker connector for corrosion, bent pins or loose fit
Check related fuses and main audio power/ground connections
Measure speaker DC resistance with speaker disconnected from amplifier

Signal parameters

Expected speaker DC resistance: typically 2–8 Ω (vehicle-specific value—consult manual)
No continuous DC offset at speaker output: DC should be near 0 V (typically
AC audio signal during playback: measurable AC waveform, often 0.5–5 Vrms depending on volume
Continuity expected between speaker + and - terminals; open = infinite Ω
No short to chassis ground or battery voltage on speaker lines

Diagnostic algorithm

Record customer report and reproduction steps (source, volume, when it occurs).
Scan vehicle for B128C and any related audio or body module faults. Note any other B-codes.
Identify physical speaker 15 location from service literature or wiring diagrams.
Visually inspect speaker, connector and harness for damage, moisture or corrosion.
With ignition off, disconnect the speaker connector and measure DC resistance of the speaker. If within spec (consult manual), continue. If open/short, replace speaker.
With speaker disconnected, check continuity and resistance of the wiring back to the amplifier/module and check for short to ground or battery.
Reconnect and backprobe amplifier output pins while playing a diagnostic/test tone to verify AC waveform and absence of DC offset; use oscilloscope if available.
Check amplifier/module supply voltage and grounds at the module. Verify fuses/relays feeding the amplifier.
If wiring and speaker are good, try swapping speaker 15 with another known-good speaker or swap amplifier channels (where applicable) to determine if the amplifier channel is faulty.
Inspect for software updates or known technical service bulletins for the audio module; perform module reflash if prescribed.
Repair or replace the failed component (speaker, wiring, connector, amplifier/module) as determined. Secure and protect wiring from future damage.
Clear codes, retest system with varied inputs and volume levels, and verify no return of B128C.

Likely causes

Speaker element failure (most common)
Broken/disconnected speaker wiring or connector
Amplifier channel fault
Corroded connector or water-damaged speaker
Intermittent connection caused by movement or rubbing harness

Fault status

⚠️ Status

Audio system detected fault on Speaker 15 circuit — possible open, short, intermittent connection, or amplifier output failure.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.5 hours

Similar codes

Repair manuals

Manual library for LAND ROVER

413

Browse 413 LAND ROVER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

LAND ROVER

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