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B1767

DTC B1767 indicates an abnormally low-resistance connection between the right front side curtain airbag inflator circuit and the vehicle positive power supply terminal (B+), resulting in a short to power — Atto 3

Safety System

DTC B1767 indicates an abnormally low-resistance connection between the right front side curtain airbag inflator circuit and the vehicle positive power supply terminal (B+), resulting in a short to power.

Under normal conditions, the airbag inflator circuit maintains high impedance (open-circuit state, with resistance typically between 2-5Ω) and conducts only momentarily when the Airbag Control Unit (ACU) triggers it.

This fault indicates the airbag circuit may remain continuously energized even if the ACU does not issue a deployment command, causing two serious consequences: 1) The airbag may deploy unexpectedly during vehicle operation, causing serious occupant injury. 2) The system detects the abnormal voltage and enters protection mode, disabling the entire SRS system and preventing airbag deployment during a collision.

This hard short-circuit fault typically causes the SRS warning lamp to illuminate continuously.

Clearing the fault code will not resolve the issue.

5
Cases Logged
5
Causes
Likely Causes — Atto 3
  • 1Right front curtain airbag wiring harness wear and insulation damage: Long-term vibration, temperature changes, or interior trim removal and installation damage the wiring harness located inside the headliner trim panels from the right A-pillar to the C-pillar. This causes the ignition wire (usually the positive trigger wire) to contact and short against a constant power circuit (such as a reading light or ambient light power wire).
  • 2Airbag connector water ingress or corrosion: Water from sunroof drain leaks, car washing, or wading causes a short circuit between terminals in the right front side airbag connector (usually located inside the B-pillar or C-pillar trim). Electrolytic corrosion creates continuity specifically between the igniter pin and the power supply pin.
  • 3Internal short circuit in the airbag module: Manufacturing defects or moisture ingress cause an internal short circuit in the curtain airbag inflator squib, creating abnormal continuity between the ignition terminals and the module metal housing (ground) or internal power supply circuit.
  • 4Vehicle modifications causing wiring harness damage: Fixing screws or wiring harness clips pierce the SRS wiring harness when installing a dash cam, roof ambient lighting, roof rack, or replacing the headliner trim, or incorrectly splicing modified wiring into the airbag circuit.
  • 5SRS control unit (ACU) internal drive circuit fault: A damaged airbag ignition drive chip (such as a MOSFET or ASIC chip) inside the ACU shorts the output terminal to the internal power supply, causing a false short-to-power fault.
What To Do
  • 1
    Safety preparation and fault confirmation: Shift the vehicle into Park or Neutral, engage the parking brake, disconnect the 12V battery negative terminal, and wait at least 90 seconds (to ensure the SRS capacitors fully discharge). Connect the diagnostic tool, confirm B1767 is an active fault, record freeze frame data, and check for other airbag circuit fault codes.
  • 2
    Visual inspection and wiring harness check: Remove the right A-pillar, B-pillar, and C-pillar interior trim panels. Inspect the right front curtain airbag wiring harness (wrapped in yellow corrugated conduit) for wear, cuts, or burn marks. Focus on contact points between the wiring harness and body metal edges, trim clips, and the sunroof drain tube. Use a multimeter to measure the resistance from the ignition wire to body ground and constant power (normal: infinite).
  • 3
    Connector inspection: Disconnect the right front side airbag connector (usually located below the B-pillar or above the C-pillar). Check the terminals for oxidation, corrosion, backed-out pins, or foreign matter. Measure the voltage at the harness-side connector terminal (should be 0V; 12V indicates a short to power). If necessary, clean the terminals with electrical contact cleaner and apply conductive protectant.
  • 4
    Airbag module inspection: Replace the airbag module with a dedicated airbag load simulator (SRS Simulator), clear the fault code, and power on again. If the fault code disappears, this confirms an internal short circuit in the airbag module; replace the right front curtain airbag module. If the fault code remains, the fault is in the wiring harness or the ACU.
  • 5
    Harness insulation repair or replacement: If the harness is damaged, wrap the damaged area with high-temperature insulating tape (Kapton tape) and re-secure the harness to prevent interference. If the harness has multiple damaged areas or an internal short circuit, replace the entire right front side airbag harness assembly to prevent recurrence.
  • 6
    SRS control unit diagnosis: Disconnect the ACU connector and measure the resistance between the right front side airbag ignition output terminal and the power supply. Continuity indicates an internal ACU fault. Replace the airbag control unit and perform coding configuration.
  • 7
    System reset and verification: After completing the repair, reconnect all connectors (listen for a locking click), connect the battery, and use the diagnostic tool to clear the fault code. Perform an SRS system self-check (normally, turning the ignition switch to ON illuminates the SRS warning light for 6 seconds before it turns off). Use the diagnostic tool to read the data stream and confirm the right front side airbag circuit resistance is within the normal range (1.5-3.5Ω). Perform static and dynamic road tests for verification.
Real-World Cases
BYD DTC AI Analysis

BYD Song MAX right front side airbag short circuit after water wading

✓
A 2019 Song MAX had the SRS warning light stay on constantly after wading through heavy rain. Read DTC B1767. Inspection revealed standing water in the right C-pillar airbag connector with oxidised, blackened terminals. The right-side sunroof drain tube had detached, allowing rainwater to run down the A-pillar and into the C-pillar trim. Fix: Cleared water from the connector, cleaned the terminals with electronic cleaner and blew dry, reattached the sunroof drain tube. Fault resolved.
BYD DTC AI Analysis

Aftermarket dash cam installation damaged wiring harness on BYD Qin Pro

✓
While installing a dashcam, the owner of a 2020 Qin Pro drove cable-clip fasteners into the right-hand A-pillar SRS harness, damaging the airbag igniter wire insulation. This caused a short to constant power and set DTC B1767. Disconnecting the airbag module changed the code to open-circuit (high resistance), confirming a wiring fault. Repaired the harness by rewrapping the insulation and rerouted the dashcam wiring to avoid the SRS harness.
BYD DTC AI Analysis

Internal short circuit in Song PLUS airbag module

✓
A Song MAX had the SRS warning light suddenly come on during normal operation. The scanner showed B1767. No wiring harness damage or connector abnormalities found. Substituting an airbag simulator cleared the fault. Confirmed internal short in the right front side curtain airbag gas generator. Repair: Replaced the right front side curtain airbag module (requires headliner removal), then performed SRS system configuration and calibration. Fault resolved.
BYD DTC AI Analysis

BYD Qin DM SRS fault after accident repairs

✓
A Qin petrol model's SRS warning light remained on after right-side collision repairs. DTC B1767. Inspection found the airbag wiring harness had been crushed by right C-pillar trim clips during the repair, deforming it and causing an internal short to the power supply. Replaced the damaged harness section (from ACU to airbag module), rerouted the wiring properly and fitted harness protection sleeving. Fault resolved.
BYD DTC AI Analysis

Internal driver chip in SRS control unit damaged

✓
A 2019 Song MAX exhibited an intermittent SRS warning light during normal operation. Fault codes cleared initially but recurred; eventually B1767 became a permanent fault. Inspection confirmed the wiring harness and airbag module tested normal. Testing revealed continuity between the right front airbag drive terminal inside the ACU and the positive power supply. Resolution: Replaced the airbag control unit (ACU), programmed the VIN and calibrated the crash sensors using a dedicated diagnostic tool. Fault completely resolved.
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.