AU
B167300

This fault code indicates a communication failure between the airbag control module (SRS ECU) and the right side impact sensor (SIS) — Atto 3

Safety System

This fault code indicates a communication failure between the airbag control module (SRS ECU) and the right side impact sensor (SIS).

On models such as the BYD Qin PRO, the right side impact sensor typically mounts inside the right front door trim panel, below the right B-pillar, or beside the right front seat.

The sensor connects to the SRS ECU via a LIN bus or hardwire to monitor real-time lateral acceleration changes on the right side of the vehicle.

The ECU triggers DTC B167300 if it fails to receive valid data frames from the sensor over several consecutive ignition cycles, detects a bus short or open circuit, or encounters a data checksum failure.

This fault may prevent the right side airbags (curtain and seat side airbags) from deploying during a side impact.

Consequently, the airbag warning lamp (SRS lamp) illuminates continuously, and the vehicle passive safety system enters degraded protection mode.

4
Cases Logged
5
Causes
Likely Causes — Atto 3
  • 1Internal circuit damage in the right side impact sensor (e.g., MEMS accelerometer chip failure or internal capacitor breakdown), commonly occurring after vehicle wading or a previous side impact.
  • 2Loose connectors, backed-out pins, oxidation, or water intrusion in the wiring harness between the sensor and the SRS ECU, especially harness wear at the door hinge and inside the sill trim caused by frequent door operation or wading.
  • 3Poor contact in the sensor power supply circuit (+B power) or ground circuit (GND) causing abnormal voltage (normal: 9-16 V; voltages below 8 V may trigger a communication fault).
  • 4Faulty SRS ECU internal communication interface driver chip or outdated software version (early Qin PRO models require an SRS software update), preventing correct sensor data parsing.
  • 5Accidental damage to the sensor wiring harness during vehicle modification or repair work (such as window tinting, routing dash cam wiring, or replacing the door trim panel), causing a hidden open or short circuit.
What To Do
  • 1
    Use the BYD VDS2000 dedicated diagnostic tool or Launch X-431 to access the SRS system. Read the complete DTC freeze frame data (record vehicle speed, temperature, and voltage when the fault occurred). Clear the fault code to distinguish between intermittent and persistent faults.
  • 2
    Visually inspect the right front door trim panel, lower B-pillar trim panel, and sill wiring harness sleeve. Check the door hinge wiring harness specifically for breaks, wear, or signs of water ingress. Inspect the right front carpet and under the seat for water stains to determine if the vehicle has flood damage.
  • 3
    Disconnect the battery negative terminal and wait at least 90 seconds to fully discharge the SRS capacitor. Remove the right side impact sensor (located in the door or B-pillar; refer to the vehicle repair manual). Inspect the connector terminals for backed-out pins, oxidation, or whitening from water ingress. Measure the voltage between pin 1 (power) and pin 2 (earth); it must equal battery voltage. Measure the voltage at pin 3 (LIN line) to earth; it must be 8-11V.
  • 4
    Disconnect the SRS ECU connector (located under the center console or center tunnel). Use a multimeter to measure the continuity of the LIN wire, power wire, and ground wire between the ECU and the sensor (should be less than 1 Ω). Measure the insulation resistance to ground and power (should be greater than 10 MΩ) to rule out an open or short circuit in the wiring harness.
  • 5
    If the wiring harness tests normal, use an oscilloscope to measure the LIN bus waveform (normally a square wave signal with a 0V dominant level and a 12V recessive level, and a typical baud rate of 19.2kbps). If the waveform is abnormal, replace the sensor. If the waveform is normal but the ECU still reports the fault, replace the SRS ECU.
  • 6
    After installing a new sensor or repairing the wiring harness, reconnect all connectors, connect the battery, and use the diagnostic tool to perform 'SRS System Configuration' or 'Sensor Calibration' (required on some models). Clear the fault code, then perform a system self-check to confirm B167300 does not return.
  • 7
    Verify the right side impact sensor function: Use the diagnostic tool to read the data stream. Moderately tap the vehicle body near the sensor mounting position by hand. Observe whether the 'Right Side Acceleration' value changes with the tapping (the value should fluctuate noticeably). Confirm the system has returned to normal.
Real-World Cases
BYD DTC AI AnalysisFrom Chinese market (translated)

Qin Pro DM: Water ingress into right front sill after wading caused sensor corrosion

✓
A 2019 Qin Pro DM presented with the airbag warning light constantly illuminated. VDS retrieved DTCs B167300 (right side impact sensor communication error) and U0151 (lost communication with SRS). Inspection revealed the vehicle had water ingress, with water pooling inside the right front sill trim. Removing the right front seat and B-pillar lower trim exposed severely oxidised, white connector pins on the side impact sensor. Removed the water, cleaned the connector with electronic cleaner, applied conductive grease, and replaced the right side impact sensor (part number: BYD-3636400). The sensor had water ingress, likely damaging its internal circuit. After replacement, the fault cleared, the SRS light went out, and the data stream returned to normal.
BYD DTC AI AnalysisFrom Chinese market (translated)

Worn right front door wiring harness causes intermittent communication fault on Qin PRO petrol version

✓
2018 BYD Qin Pro petrol. Airbag warning light intermittently illuminated, particularly when driving over speed bumps. Scan tool showed B167300 as a historical fault. Inspected wiring harness at right front door hinge area and found harness sheath cracked from repeated door opening and closing. Internal LIN signal wire copper strands had fractured with only a few strands remaining connected, causing intermittent open circuit. Repair: cut out damaged harness section, re-soldered wires, and applied waterproof insulation. Adjusted harness routing to avoid chafing against door metal edge and fitted protective corrugated conduit. Road tested 50 km after repair; fault did not return.
BYD DTC AI AnalysisFrom Chinese market (translated)

Door speaker modification caused the sensor connector to come loose.

✓
A 2019 Qin Pro DM developed an illuminated airbag warning light after the owner modified the right front door speaker. The fault code B167300 was read. Inspection found that the person who did the modification had not properly reconnected the side impact sensor connector (mounted inside the door trim panel) during removal and refitting of the right front door trim panel. The plug was not fully locked, causing intermittent contact from vehicle vibration. The technician firmly reconnected the sensor connector, ensured the lock tab fully engaged, secured the wiring harness with cable ties to prevent movement, and cleared the fault code. The system returned to normal afterward.
BYD DTC AI AnalysisFrom Chinese market (translated)

After accident repair, unconfigured sensors cause communication error in Qin Pro EV.

✓
2020 BYD Qin Pro EV. After a right-side side impact collision, a workshop replaced the right front door and side impact sensor. The airbag warning light stayed on, logging DTC B167300. Inspection found the replacement sensor was an aftermarket part and the new sensor configuration had not been performed using BYD VDS. Qin Pro vehicles require online configuration after SRS component replacement; otherwise the ECU cannot recognise the new sensor ID code. Solution: Used a genuine VDS2000 diagnostic tool to access ‘SRS System – Special Functions – Configuration/Coding’, ran the right side impact sensor configuration, then cleared the DTCs. SRS self-test passed.
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: Official This information is for reference only. Always consult a qualified technician for diagnosis and repair. Do not attempt high-voltage system repairs yourself. Sources: [1]