AU
B173611

DTC B173611 indicates the SRS (Supplemental Restraint System) control unit detects an abnormal short to body ground in the firing circuit of the right second-row side airbag module (typically located on the side of the right second-row seat or the lower B-pillar) — Atto 8

Safety System

DTC B173611 indicates the SRS (Supplemental Restraint System) control unit detects an abnormal short to body ground in the firing circuit of the right second-row side airbag module (typically located on the side of the right second-row seat or the lower B-pillar).

The airbag module contains an electric squib (igniter) controlled by the airbag ECU, with a normal resistance between 1.5 and 2.5 Ω.

The diagnostic system logs a short to ground when the circuit-to-ground resistance drops below the threshold (typically under 1 Ω or a specific calibrated value).

This fault produces the following consequences: 1) The side airbag fails to deploy during a collision, resulting in a loss of side-impact protection; 2) In extreme cases, short-circuit current triggers unintended airbag deployment, causing occupant injury; 3) The SRS enters fail-safe mode, disabling the entire vehicle airbag system.

This constitutes a highest-severity electrical safety fault requiring immediate repair.

The B173611 fault code on the Atto 8 indicates a high-severity SRS fault: a short to body ground in the right second-row side airbag firing circuit. This can stop the side airbag from working and may disable the airbag system. Common causes include a damaged airbag igniter or worn/pinched wiring near the seat rail or B-pillar. Visit an authorised dealer immediately for diagnosis and repair. Typical repair cost data is available.
3
Cases Logged
5
Causes
Likely Causes — Atto 8
  • 1Airbag module internal igniter coil short circuit: Moisture, aging, or manufacturing defects in the squib inside the right middle-row side airbag module damage the internal coil insulation, causing direct continuity to the module metal housing (ground).
  • 2Physical wiring harness damage: Frequent seat adjustment, foreign object pinching, or vehicle vibration wears the wiring harness insulation near the seat rail, inside the B-pillar trim panel, or under the floor, causing the signal wire to directly contact the body metal.
  • 3Connector water ingress and corrosion: Vehicle wading, a blocked sunroof drain tube, or interior cleaning allows moisture to enter the right middle-row side airbag connector, causing pin oxidation and creating a short-to-ground path.
  • 4SRS ECU internal fault: Airbag control unit internal monitoring circuit malfunctions and falsely reports a short-to-ground fault (relatively uncommon; rule out wiring issues before confirming).
  • 5Improper repair procedures: During seat removal and installation, interior trim modification, or audio system modification, tools pierce the wiring harness, or failing to reinstall retaining clips causes the wiring harness to rub against the vehicle body and short circuit.
What To Do
  • 1
    Safety pre-operation: Set the vehicle to OFF, disconnect the low-voltage battery negative terminal, and wait at least 90 seconds (to fully discharge the SRS capacitor and prevent accidental airbag deployment).
  • 2
    Initial visual inspection: Remove the right middle-row seat side trim panel or lower B-pillar trim panel. Inspect the airbag module for external damage, the wiring harness for obvious damage or burn marks, and the connector for looseness or water ingress.
  • 3
    Circuit isolation diagnosis: Disconnect the SRS control unit connector. Use a multimeter to measure the resistance between the right middle-row side airbag pin (refer to the circuit diagram, usually the B1736 channel) and body ground. Normal resistance is greater than 1 MΩ (open circuit). A resistance less than 1 Ω confirms a short to ground.
  • 4
    Segmented fault isolation: Disconnect the wiring harness at the airbag module connector. Measure the resistance to ground on the harness side and the module side separately. If the module side shows a short circuit, replace the airbag module. If the harness side shows a short circuit, inspect the wiring routing. Focus on chafing points at the seat rails and detached harness retaining clips.
  • 5
    Repair and Verification: Repair the damaged wiring harness (protect with waterproof insulating tape and corrugated conduit) or replace the faulty airbag module. Reconnect all connectors and ensure the locking tabs engage fully. Connect the battery, clear the fault code using the VDS or X431 diagnostic tool, and perform the SRS system self-check procedure. Confirm B173611 does not return and the airbag warning light turns off.
  • 6
    Function check: Perform static and dynamic tests, including simulated vehicle start-up and driving on bumpy roads. Verify the fault does not recur.
Real-World Cases
BYD DTC AI Analysis

Worn seat rail wiring harness caused a short to ground

✓
Vehicle: 2019 BYD E2, 60,000 km. The customer reported an intermittent airbag warning light on the instrument cluster. Using VDS, the technician retrieved DTC B173611. After removing the right-hand rear seat, the technician found the seat track adjustment mechanism had worn through the airbag wiring harness corrugated tubing over time, allowing the copper core to directly contact the seat metal frame and short to ground. Repair: Cut out the damaged harness section, soldered in extension wires, insulated the splices with double-layer heat shrink tubing, and rerouted the wiring away from the seat track travel path. Fault resolved.
Original source ↗
BYD DTC AI Analysis

After wading, water entered the connector, causing corrosion and a short circuit.

✓
Vehicle: 2019 BYD Qin EV. Warning light illuminated after driving through water in heavy rain. Scan tool displayed code B173611 and could not clear it. Inspection found damp carpet beneath the right rear seat. Removing the side airbag connector revealed obvious water stains and green copper corrosion inside. Cause: aged door seal allowed rainwater to seep in and pool at the floor wiring harness connector. Fix: cleaned connector oxides thoroughly, sprayed electronic cleaner and dried, applied conductive grease, replaced the waterproof seal, and cleared the fault codes. System returned to normal.
Original source ↗
BYD DTC AI Analysis

Connector not reconnected after accident repair caused short circuit

✓
Vehicle: 2020 BYD E3. After a repair shop replaced the B-pillar trim following a right rear door accident, the instrument cluster displayed an airbag warning. Fault code B173611 was stored. Inspection revealed the technician had not fully seated the airbag connector when installing the right rear side airbag module (locking tab unengaged). The plug tilted, allowing the signal pin to contact the body metal and short to earth. Rectification: Reconnected the airbag module connector correctly, ensuring the locking tab clicked into place. Secured the wiring harness with cable ties to eliminate strain. Cleared the DTC and completed airbag system calibration.
Original source ↗
Other Atto 8 Fault Codes
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.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.B110A02DTC B110A02 indicates the thermal management master control unit (HVAC ECU) or body control module (BCM) failed to receive valid CAN data frames from the PM2.5 air quality sensor over consecutive communication cycles (typically 500ms per cycle). The sensor typically mounts at the HVAC unit air inlet or behind the glove box and transmits real-time particulate concentration data (unit: μg/m³) to the HVAC controller via the CAN bus. The fault is essentially a communication link layer timeout. Potential causes include physical layer wiring faults, sensor power supply failures, sensor internal MCU lockup, or CAN network topology damage. Although this non-critical fault does not directly affect driving safety, it disables the intelligent air purification strategy and the automatic fresh air/recirculation switching function. In extreme cases, it triggers a thermal management system degraded mode, limiting compressor power or fixing the air flap position.B110B07This fault code indicates abnormal operation of the internal air pump (sampling pump) in the PM2.5 air quality detection module. The PM2.5 detector uses the laser scattering principle to measure particulate concentration and requires a built-in air pump to draw ambient air into the detection chamber at a constant flow rate. The ECU sets this code when it detects an open or short in the air pump drive circuit, abnormal current (stall or free-running), or abnormal speed feedback. This fault causes the automatic air conditioning system to lose air quality sensing capability, preventing automatic switching between fresh air and recirculation modes. The instrument cluster air quality display may show '--' or a fixed value, but the fault does not affect the vehicle powertrain or basic air conditioning cooling and heating functions.B173CDTC B173C indicates the Supplemental Restraint System (SRS) detects the Right Second Row Side Airbag squib circuit resistance exceeds the calibrated threshold (typically >4.5Ω). This fault is an active diagnostic result of the SRS system, indicating a high-resistance condition in the circuit between the Airbag Control Unit (ACU) and the airbag module. Causes for excessive resistance include increased contact resistance, a partially broken wiring harness, terminal oxidation, or an aging squib wire inside the airbag module. This fault causes the system to mark the airbag circuit as 'unreliable', meaning the airbag may fail to deploy during a collision. The fault typically illuminates the instrument cluster airbag warning light (SRS light) continuously, and some models also sound a warning buzzer.
Common problems reported for Atto 8 →Atto 8 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.