Damaged or disconnected wiring harness at the pedestrian alert speaker, often from road debris, curb strikes, or rodent damage.; Corroded or loose electrical connector at the speaker or at the control module.; Failed pedestrian alert speaker (open voice coil or water intrusion).; Faulty body control module or dedicated acoustic vehicle alerting system (AVAS) module.; Blown fuse or poor ground connection for the speaker circuit.; Software glitch in the module that requires reflash or calibration.; Aftermarket modifications or accident repairs that disturbed the speaker wiring.

DTC codes / B01xx · Airbags, seats, doors, lights and comfort systems / B0122

B0122Pedestrian Alert Speaker A

Q: What does code B0122 mean?

Pedestrian Alert Speaker A. B0122 indicates a fault in the Pedestrian Alert Speaker A circuit, which is the sound generator that hybrid and electric vehicles use to warn pedestrians at low speeds. The body control module or dedicated sound module has detected an open, short, or performance issue with that speaker circuit.

B0122 indicates a fault in the Pedestrian Alert Speaker A circuit, which is the sound generator that hybrid and electric vehicles use to warn pedestrians at low speeds. The body control module or dedicated sound module has detected an open, short, or performance issue with that speaker circuit.

SystemBody

Code typeGeneric (all makes)

SeverityLow

Fix difficultyIntermediate

AreaAirbags, seats, doors, lights and comfort systems

Symptoms you may notice

Often no symptoms besides the warning light, because the pedestrian alert sound is only noticeable at very low speeds in quiet environments.
Reduced or absent pedestrian warning sound when driving below roughly 20 mph (30 km/h).
A clicking, popping, or distorted noise from the front of the vehicle when the alert system should be active.
A message on the dash such as 'Pedestrian Alert System Fault' or 'Acoustic Vehicle Alerting System Unavailable'.
The alert sound may work intermittently depending on temperature or moisture.
Other driver-assist chimes or warnings may also be affected if they share the same speaker or module.

Common causes, most likely first

Damaged or disconnected wiring harness at the pedestrian alert speaker, often from road debris, curb strikes, or rodent damage.
Corroded or loose electrical connector at the speaker or at the control module.
Failed pedestrian alert speaker (open voice coil or water intrusion).
Faulty body control module or dedicated acoustic vehicle alerting system (AVAS) module.
Blown fuse or poor ground connection for the speaker circuit.
Software glitch in the module that requires reflash or calibration.
Aftermarket modifications or accident repairs that disturbed the speaker wiring.

How to diagnose and fix it

Verify the code with a scan tool and check for any related body or communication codes before touching hardware.
Inspect the pedestrian alert speaker and its connector for physical damage, corrosion, or loose pins.
Check the fuse and ground for the speaker circuit using a wiring diagram.
Measure resistance across the speaker terminals and compare to specification; also check for short to ground or power on the harness.
If the speaker tests good, back-probe the module connector to confirm the module is commanding the speaker during an active test.
Repair or replace damaged wiring, connectors, or the speaker as needed.
Clear the code and perform a road test at low speed to confirm the alert sound operates and the code does not return.

Pedestrian alert faults that fool good technicians

A common misdiagnosis is replacing the speaker when the real fault is a chafed harness behind the front bumper that only shorts when the steering is turned or the suspension compresses.
Some vehicles use the same speaker for other warning chimes, so a fault may first show up as a missing seatbelt reminder or door chime rather than a pedestrian alert issue.
The code can set intermittently from water intrusion after a car wash or heavy rain, and the speaker may test fine once dried out, so always inspect for moisture trails.
On many hybrids and electric vehicles, the pedestrian alert system is silent above a certain speed by design, so a road test must be done at very low speed to confirm the repair.
A weak or failing 12-volt battery can cause body modules to log false speaker circuit codes, so check battery health before condemning the speaker or module.

Can I keep driving with B0122?

The vehicle remains safe to drive because the pedestrian alert is a supplementary warning system, but you should be extra cautious in parking lots and other areas with pedestrians since the vehicle may be quieter than expected at low speed. Avoid relying on the alert sound until the fault is repaired.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.