AU
B175111

This DTC indicates the Supplemental Restraint System (SRS) detected an abnormally low-resistance connection (short to ground) between the right rear side airbag squib circuit (typically located on the outer side of the right rear seat or inside the C-pillar trim panel) and vehicle chassis ground (GND) — Atto 3

Safety System

This DTC indicates the Supplemental Restraint System (SRS) detected an abnormally low-resistance connection (short to ground) between the right rear side airbag squib circuit (typically located on the outer side of the right rear seat or inside the C-pillar trim panel) and vehicle chassis ground (GND).

Under normal conditions, the airbag squib circuit maintains a specific resistance (approximately 2-3Ω).

When the ACU (Airbag Control Unit) detects circuit resistance near 0Ω, it registers a short to ground.

This constitutes a critical safety fault.

The system immediately illuminates the SRS warning lamp and disables the right rear side airbag and related coordinated protection functions to prevent accidental deployment while driving or deployment failure during a collision.

The B175111 fault code on the Atto 3 indicates a high-severity SRS fault where the right rear side airbag squib circuit has a short to ground. This can disable the right rear side airbag and related protection functions, with the SRS warning light on. Common causes include damaged wiring insulation near the seat or trim, or water-related corrosion in SRS connectors. Visit an authorised dealer for diagnosis and repair. Typical repair cost data is available from recorded cases.
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Cases Logged
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Causes
Likely Causes — Atto 3
  • 1Right rear side airbag wiring harness insulation wear: Continuous chafing against the seat frame, C-pillar trim panel retaining clips, or door sill trim edges wears through the harness insulation, grounding the internal wires directly to the metal vehicle body.
  • 2Water ingress and oxidation at the under-seat or B/C-pillar connectors: A blocked rear sunroof drain, poor rear windshield sealing, or water entering the right rear door sill during washing causes the internal pins of the yellow SRS connector to short circuit or short to ground.
  • 3Wiring harness fatigue from frequent seat adjustment: Frequent forward and backward sliding of the right rear seat pinches and overbends the airbag wiring harness at the seat rail, breaking the internal copper wires and causing a short to ground.
  • 4Improper repair work: fixing screws or clips pierce the airbag wiring harness during removal/installation of the right rear seat or C-pillar interior trim panel, or when laying floor coverings/mats, causing a short to ground.
  • 5Airbag module internal fault: Right rear side airbag igniter internal bridge wire shorted to housing (very rare; other airbags usually set fault codes simultaneously).
What To Do
  • 1
    Safe power-down: Turn off the ignition, disconnect the negative battery terminal, and wait at least 90 seconds to fully discharge the SRS capacitor and prevent accidental airbag deployment.
  • 2
    Locate component: Confirm the right rear side airbag installation location (Qin Pro models typically house this inside the right rear seat outer backrest or the C-pillar). Remove the right rear seat or lower C-pillar trim panel to expose the yellow SRS wiring harness connector.
  • 3
    Visual inspection: Check the wiring harness at the seat track, C-pillar mounting point, and door sill transition for signs of pinching, cuts, or wear. Check the connector for green corrosion, water stains, or bent pins.
  • 4
    Resistance measurement: Disconnect the Airbag Control Unit (ACU) connector. Use a multimeter to measure the resistance between the right rear side airbag circuit pin and body ground. The normal reading is infinity (OL). Continuity indicates a short circuit.
  • 5
    Sectional inspection: Measure wiring harness continuity in sections between the seat connector and the ACU. Perform a wiggle test (measure while wiggling the harness) to locate the short circuit. If the wiring harness is normal, use the special load tool substitution method to measure the airbag assembly resistance.
  • 6
    Repair procedure: If the wiring harness is damaged, strip the insulation, solder the break, and insulate it with double-layer heat-shrink tubing. Adjust the wiring harness routing to avoid contact with sharp edges. If water entered the connector, thoroughly clean and dry it, then apply conductive grease. Replace the waterproof connector if necessary.
  • 7
    System verification: Restore all connections, reinstall the seat, and connect the battery. Use the diagnostic tool to clear the fault code and perform an SRS system self-test. Confirm B175111 does not return and the instrument cluster airbag warning light turns off. Perform a multi-directional seat adjustment test to verify the fault does not recur.
Real-World Cases
BYD DTC AI Analysis

Right rear seat wiring harness winding mechanism internal break and short circuit

✓
Symptoms: SRS warning light stays on after starting the vehicle. The right rear seat had been adjusted frequently. Diagnosis found current fault code B175111. Removed and inspected the right rear seat. Found the side airbag harness wires had fatigue-fractured inside the winding mechanism (similar to a clock spring) at the junction between the seat back and cushion. The broken ends touched the metal seat frame, causing a short to ground. Repair: Replaced the right rear seat airbag harness assembly (including the winding mechanism). Re-secured the harness routing to ensure no interference throughout the full range of seat adjustment.
BYD DTC AI Analysis

Right rear door sill wiring harness connector corroded due to water ingress

✓
Symptoms: The SRS warning light came on after driving in heavy rain or washing the vehicle, and the right rear floor mat was damp. Diagnostics showed intermittent DTC B175111. Inspection found significant water staining and green corrosion inside the yellow SRS connector behind the right rear sill trim panel, with the connector pins showing continuity to ground. Root cause: The sunroof rear drain hose had detached, allowing water to run down the C-pillar and into the sill. Resolution: Unclogged and secured the drain hose. Removed the connector, cleaned the pins with electronic contact cleaner, dried them, applied silicone grease, and replaced the waterproof seal. Fault resolved.
BYD DTC AI Analysis

Seat rail pinched wiring harness after seat removal and refitting

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Symptoms: After replacing the right rear seat cover, the airbag warning light illuminated. Diagnostics retrieved code B175111 which would not clear. Diagnosis: The airbag wiring harness was not properly secured during the repair and got trapped between the seat rail and body. Adjusting the seat caused the metal edge to cut through the harness insulation, shorting the wire to ground. Repair: Released the seat mounting bolts and extracted the crushed harness. Cut out the damaged section, re-soldered and re-insulated the wires. Secured the airbag harness to a safe position on the seat frame using dedicated harness clips.
BYD DTC AI Analysis

Internal drive circuit fault in the airbag control module

✓
Symptoms: Fault persisted after ruling out the wiring harness and airbag components; or multiple airbags simultaneously reported short-to-ground faults after water ingress (e.g., B175111, B175211). Diagnosis: Disconnected the right rear airbag connector. Continuity from the harness to the ACU and insulation to ground both tested normal. Measured abnormally low resistance from the corresponding ACU pin to ground. Determined an internal ACU drive MOSFET or filter capacitor breakdown caused a short circuit. Repair: Replaced the airbag control module, performed online programming and matching (synchronised VIN, immobiliser and tyre pressure data), and completed system calibration.
Other Atto 3 Fault Codes
P0AA6Hybrid Battery Voltage System Isolation FaultB1108For 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.B1109DTC B1109 indicates an open circuit in the communication line between the air conditioning system PM2.5 air quality sensor (dust concentration sensor) and the air conditioning control unit (AC ECU), or an open circuit within the sensor internal circuitry. Typically located in the air conditioning intake duct, this sensor monitors real-time PM2.5 particle concentration inside and outside the vehicle. It provides data to the automatic air conditioning system for intelligent switching between fresh air and recirculation modes and for controlling the air purification device. During an open circuit fault, the AC ECU cannot receive the air quality signal, triggering the system fail-safe mode. Symptoms typically include failure of the automatic recirculation function, abnormal air purification indicator light operation, or abnormal air quality data displayed on the air conditioning panel. Severe cases may compromise the cabin environment control strategy, but do not directly affect vehicle driving safety.B110AThis DTC indicates interrupted CAN bus communication or abnormal data between the air conditioning control unit (ACU) and the PM2.5 air quality sensor. The PM2.5 sensor monitors particulate concentration inside and outside the vehicle and provides the basis for purification control in the automatic air conditioning system. The ACU triggers this fault if it fails to receive a valid CAN message from the sensor within the specified period (usually 100-500 ms), if message verification fails, or if the signal frame times out. Although this fault does not affect vehicle driving safety, it disables the automatic air purification function. The air conditioning system cannot automatically switch between recirculation and fresh air modes or activate the air purification mode based on air quality. A persistent fault may restrict the thermal management strategy.B173A1ADTC B173A1A indicates the right middle-row side airbag (typically located on the side of the right second-row seat or inside the C-pillar trim panel) igniter circuit resistance measures 0 Ω. In the Supplemental Restraint System (SRS), normal airbag igniter resistance ranges between 2.0 and 5.0 Ω. A resistance of 0 Ω indicates a short to ground or a short between circuit wires, preventing the Airbag Control Unit (ACU) from establishing a normal monitoring circuit. This safety-critical fault prevents the airbag from deploying during a collision, continuously illuminates the instrument panel SRS warning lamp, and may force the entire airbag system into fail-safe mode.
Common problems reported for Atto 3 →Atto 3 overview →
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.