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B16A100

DTC B16A100 actually indicates an AVAS (Acoustic Vehicle Alerting System) fault, not an SRS airbag system fault — Atto 3

Safety System

DTC B16A100 actually indicates an AVAS (Acoustic Vehicle Alerting System) fault, not an SRS airbag system fault.

This DTC signifies the Pedestrian Warning Speaker has an open or short circuit, or the AVAS control module detects a speaker circuit fault.

AVAS is a mandatory safety feature on new energy vehicles that simulates engine sound to warn pedestrians at low speeds (0-20 km/h).

The system triggers this DTC when it detects abnormal speaker circuit resistance (normal range: 4-8 Ω), a wiring short to ground or open circuit, or an internal control module fault.

This disables the low-speed warning sound and compromises safety compliance.

5
Cases Logged
Real-World Cases
BYD DTC AI Analysis

BYD Han EV pedestrian warning speaker open circuit fault

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Symptoms: After starting the vehicle, the dash displayed "Please check pedestrian warning system". No alert sound during low-speed driving. Diagnosis: Used VDS2000 to read DTC B16A100. Measured the pedestrian warning speaker resistance as infinite (open circuit). Inspected the connector and found the plug loose with oxidised terminals. Solution: Cleaned the oxidised terminals and applied conductive paste. Reconnected and secured the connector. Cleared the fault code, and the system returned to normal.
Original source ↗
BYD DTC AI Analysis

BYD Qin Pro DM Speaker Short Circuit Burnout Case

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Symptoms: Dashboard displayed "AVAS System Fault". No simulated engine sound at low speeds in EV mode. Diagnosis: Retrieved DTC B16A100. Live data showed speaker status "open circuit". Measured speaker resistance: 0 Ω (short to ground). Determined internal coil burnout. Solution: Replaced pedestrian warning speaker assembly (Part No. BYD-1102930-00). Performed AVAS system self-learning. Function returned to normal.
Original source ↗
BYD DTC AI Analysis

Wiring loom chafing caused an intermittent fault on BYD Yuan PLUS

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**Symptoms:** Intermittent B16A100 fault code after 5,000 km on new vehicle. Warning tone cuts in and out accompanied by static noise. **Diagnosis:** Stored faults indicated intermittent open circuit. AVAS module power supply tested normal. Found wiring harness with chafed insulation at inner fender liner, causing intermittent short to ground. **Solution:** Repaired damaged wiring and wrapped with waterproof tape. Adjusted routing and fitted protective sleeving. Cleared fault codes and road test confirmed normal operation.
Original source ↗
BYD DTC AI Analysis

BYD Dolphin speakers water-damaged after wading

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Symptom: After driving through water about 30 cm deep, the dash displayed a pedestrian warning system fault. DTC B16A100 could not be cleared. Diagnosis: Inspected the right-front speaker in the front compartment. Found water ingress marks on the housing, a corroded diaphragm edge, and unstable resistance measurements. Resolution: Replaced the water-damaged speaker. Checked the mounting point sealing and added an extra gasket. Advised against driving through water.
Original source ↗
BYD DTC AI Analysis

Aftermarket audio installation caused wiring fault in BYD Tang DM-i

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Symptoms: After an independent shop modified the audio system, a B16A100 fault code appeared. Diagnosis: We asked the shop and learned they had removed front compartment components. Inspection found the pedestrian warning speaker negative wire had been cut and incorrectly used as the audio ground, causing an AVAS module circuit fault. Solution: We restored the factory wiring harness connections, correctly reconnected the speaker negative wire to the AVAS module, repaired other modification damage, and the fault cleared.
Original source ↗
Other Atto 3 Fault Codes
P0A0DBattery Energy Control Module Requested MIL IlluminationP0AA6Hybrid Battery Voltage System Isolation FaultP1A00Drive Motor "A" Performance — BYD proprietaryB1108For the BYD Song MAX (2017–2019), DTC B1108 indicates a short circuit in the PM2.5 air quality detection module (dust sensor) or its wiring harness. The sensor uses laser scattering to detect in-cabin and outside PM2.5 concentrations and transmits data to the HVAC ECU via the LIN bus or an analog signal. Short circuit conditions include: 1) Sensor power supply wire (+5V/+12V) shorted to ground 2) Signal wire shorted to power or ground 3) Short circuit in the sensor's internal photoelectric detection circuit This fault prevents the automatic climate control from switching between fresh air and recirculation based on air quality. The system enters fail-safe mode (typically forced recirculation). Severe short-circuit current can destroy the HVAC ECU sampling circuit. The system classifies this as a Level 3 severe fault and restricts vehicle operation to prevent electrical fires or controller damage. For other BYD models (such as the Qin EV, E5, and Song DM), B1108 indicates a driver-side sunload sensor fault, reflecting differences in DTC definitions across models.B110811This DTC indicates a short circuit in the air conditioning system PM2.5 air quality sensor (rapid detector). Specifically, abnormal continuity exists between the sensor power supply circuit or signal output circuit and body ground or battery positive. This causes the control module (ACU/air conditioning controller) to detect abnormal current or a voltage signal outside the valid range (typically 0V or supply voltage). The PM2.5 sensor monitors internal and external particulate concentrations, providing the data the automatic air conditioning system uses to switch between fresh air and recirculation modes. A short circuit disables the air quality monitoring function. This fault may force the air conditioning system into recirculation protection mode and trigger related thermal management system faults, as the air conditioning system acts as a key actuator in vehicle thermal management. In severe cases, the short circuit current can damage the internal sampling circuit of the air conditioning controller or overheat the wiring harness.
Data confidence: Community This information is for reference only. Always consult a qualified technician for diagnosis and repair. Do not attempt high-voltage system repairs yourself.