AU
B1741-00

DTC B1741-00 indicates the airbag system (SRS) control module detected a short to ground in the Left Rear Side Airbag deployment circuit — Seal U

Safety System

DTC B1741-00 indicates the airbag system (SRS) control module detected a short to ground in the Left Rear Side Airbag deployment circuit.

The SRS ECU continuously monitors the airbag inflator resistance via its internal diagnostic circuit (normal range: 2.0-3.0 ohms).

When the system detects an abnormally low circuit resistance (near 0 ohms) or a short-to-ground path, it logs a short-to-ground fault.

This fault prevents the affected airbag from deploying during a collision or, in extreme cases, risks unintended deployment due to wiring faults.

Consequently, the SRS immediately illuminates the airbag warning lamp and disables the entire airbag system to protect occupants.

3
Cases Logged
5
Causes
Likely Causes — Seal U
  • 1Damaged or worn left rear seat side airbag wiring harness: Frequent fore/aft seat adjustment or passenger entry and exit damages the harness insulation at seat frame friction points, causing the wire to contact vehicle body metal and create a short to ground.
  • 2Water ingress or corrosion in the wiring harness connector under the seat: Liquid seeps into the yellow SRS connector under the left rear seat during interior cleaning, causing a short circuit between terminals or a short to ground.
  • 3Airbag igniter internal fault: Short circuit in the left rear side airbag module internal igniter element. Possible causes include a manufacturing defect or hidden damage from an unreplaced module after a vehicle accident.
  • 4Improper seat modification or repair: When installing seat heating pads or leather upholstery, or during seat repairs, mounting screws pierce or pinch the wiring harness, causing insulation damage.
  • 5SRS ECU internal diagnostic circuit fault: In very rare cases, the airbag control module internal monitoring circuit reports a false fault. Rule out by substitution.
What To Do
  • 1
    Safety preparation: Disconnect the 12V battery negative terminal and wait at least 3 minutes to discharge the residual charge in the SRS capacitor to prevent accidental airbag deployment.
  • 2
    Visual inspection: Remove the left rear seat and side trim panel. Inspect the yellow SRS wiring harness for obvious damage or crush marks, focusing on the harness fixing points and bends near the seat rail.
  • 3
    Connector check: Disconnect the left rear side airbag module connector (usually located below the seat backrest or near the C-pillar). Check the terminals for corrosion, water ingress, or foreign metal objects.
  • 4
    Resistance measurement: Use a multimeter to measure the airbag-side wiring harness resistance to ground (must be greater than 10kΩ or infinite). If the resistance is near 0Ω, the wiring harness has a short to ground. Measure the airbag module resistance (must be 2.0-3.0Ω; replace the airbag module if out of range).
  • 5
    Wiring harness repair: If the wiring harness is damaged, use high-temperature insulating tape or replace the entire harness section (simple wrapping is prohibited). Maintain sufficient clearance between the wiring harness and the seat frame, and re-secure the harness.
  • 6
    Replacement verification: If the wiring harness is normal but the fault persists, replace the left rear side airbag module to cross-check.
  • 7
    System reset: After repair, reconnect all connectors and the battery. Use the BYD dedicated diagnostic tool (VDS or ED400) to clear the fault code and perform an SRS system self-check. Confirm B1741-00 does not reappear and the airbag warning light turns off.
Real-World Cases
BYD DTC AI Analysis

Seat adjustment on a Qin EV450 caused wiring harness wear and a short circuit.

✓
A 2018 Qin EV450 with 42,000 km displayed a constant airbag warning light on the dashboard. Technicians retrieved DTC B1741-00. Removing the left rear seat revealed interference between the left edge of the seat frame and the SRS wiring harness retaining clip. Long-term seat adjustment chafed through the harness insulation, exposing copper conductors and causing a short to earth where they contacted the metal seat frame. Repair: replaced a 30 cm section of damaged wiring, rerouted the harness and added abrasion-resistant corrugated tubing, and fitted a rubber edge guard over the sharp frame edge to prevent further wear. Cleared the fault code and the system returned to normal.
BYD DTC AI Analysis

Qin 100 airbag short circuit after interior cleaning

✓
2017 BYD Qin 100. After a deep interior cleaning at a car wash, the airbag warning light came on the next day. The diagnostic tool displayed code B1741-00. Technicians found water stains inside the SRS connector (yellow 2-pin) under the left rear seat, with terminals oxidised and blackened. During cleaning, the high-pressure water gun sprayed directly into the seat gaps, allowing water to enter the connector and cause a short circuit. They thoroughly cleaned the connector with electronic contact cleaner, blow-dried it, and applied conductive anti-corrosion grease. They sealed the connector with waterproof tape and checked the airbag module resistance (normal). Clearing the fault codes resolved the fault.
BYD DTC AI Analysis

Airbag fault triggered by aftermarket heated seat modification

✓
A 2017 Qin 80 developed DTC B1741-00 following installation of rear seat heating at a third-party workshop. Inspection found metal retainers securing the seat upholstery had pierced the left rear side airbag harness while fitting the heating pads, damaging two wires and causing a short to earth. Technicians removed the heating pads, replaced the damaged SRS harness (complete section from main harness branch point to airbag module), and rerouted the wiring to avoid the heating pad mounting points. They recommended using genuine parts or professional retrofit solutions if seat heating is needed.
Other Seal U Fault Codes
B1108For 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.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.B110913DTC B110913 indicates an open signal circuit for the PM2.5 rapid detector (in-cabin air quality sensor). This sensor typically mounts inside the air conditioning system intake duct. It monitors in-cabin PM2.5 concentration in real time and provides data to the automatic air conditioning system for intelligent control of the air purification function. The BYD diagnostic protocol uses sub-code '13' to specifically indicate an open signal circuit. Although this fault theoretically affects a comfort feature, BYD Qin series vehicles classify it as a Level 3 (severe) fault. This classification occurs because the air conditioning system interacts with the battery thermal management system (e.g., monitoring battery cooling intake air quality). The fault can disable the automatic air conditioning mode and prevent the air purification function from operating. In extreme cases, it affects the battery compartment intake air quality assessment, triggering the 'repair immediately' strategy.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.
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.