AU
B1712-00

This DTC indicates the RH Curtain Shield Airbag igniter circuit resistance measures 0 Ω, indicating a typical short circuit — Qin Plus

Safety System

This DTC indicates the RH Curtain Shield Airbag igniter circuit resistance measures 0 Ω, indicating a typical short circuit.

Normal airbag igniter resistance is 2.0-5.0 Ω.

A 0 Ω resistance typically indicates a short to ground in the igniter circuit (damaged harness insulation), a short to power (contact with constant power), or a shorted driver transistor inside the airbag control module (SRS ECU).

This fault forces the SRS system into fail-safe mode: the affected airbag will not deploy during a collision (the short circuit diverts the deployment current), and the airbag warning lamp illuminates continuously.

Some models simultaneously disable the front seat belt pretensioners and the corresponding side airbag.

The short circuit also carries a minimal risk of unintended deployment.

Immediately remove the vehicle from service for repair.

5
Cases Logged
5
Causes
Likely Causes — Qin Plus
  • 1The right curtain airbag wiring harness chafes or pinches at the C-pillar trim panel or headliner retaining strip, shorting the wire to body ground.
  • 2Airbag connector (usually located at the right C-pillar or front of the headliner): short circuit caused by fused internal terminals, electrolytic corrosion from water ingress, or metal debris.
  • 3Internal short circuit in the right curtain airbag igniter (gas generator bridge wire insulation breakdown), typically occurring after vehicle wading or when the airbag exceeds its service life.
  • 4SRS ECU internal driver circuit fault (power transistor breakdown) or software calibration error causing abnormal resistance sampling.
  • 5Improper repair procedure: Measuring airbag terminals directly with an analog multimeter or low-impedance digital multimeter generates high current, burning out the igniter or logging a false short circuit record.
What To Do
  • 1
    Safety preparation: Disconnect the 12V battery negative terminal and wait at least 90 seconds to fully discharge the SRS backup power capacitor; remove the smart key and place it 3 metres away.
  • 2
    Initial inspection: Remove the right C-pillar trim panel and right headliner trim panel. Visually inspect the curtain airbag wiring harness (yellow sleeve) for wear, cuts, or crush marks. Focus on the C-pillar hinge area and headliner harness retaining clip locations.
  • 3
    Connector diagnosis: Disconnect the SRS ECU connector (located under the center console or in the front compartment) and the right curtain airbag connector (usually a yellow 2-pin plug). Inspect the terminals for backed-out pins, corrosion, verdigris, or metal debris. Clean with electronic contact cleaner if necessary.
  • 4
    Harness continuity test: Use a high-impedance digital multimeter (≥10MΩ) to measure the airbag circuit resistance to ground. The standard value should be ≥1MΩ. Measure the continuity between both ends of the harness and confirm no short to ground or power.
  • 5
    Airbag module isolation test: Substitute the right curtain airbag with a dedicated airbag simulator (2Ω/0.25W). Connect the diagnostic tool, clear the fault code, and read the codes again. If B1712-00 disappears, this indicates an internal short circuit in the airbag module. Replace the right curtain airbag assembly.
  • 6
    SRS ECU inspection: If the wiring harness and airbag module are normal, measure the resistance between the corresponding SRS ECU pins. If the resistance remains 0 Ω, replace the SRS control module and write the Vehicle Identification Number (VIN) and configuration code.
  • 7
    System verification: Restore all connections, turn on the power, and use the dedicated diagnostic tool to perform the "SRS System Self-Diagnosis" and "Crash Output Test" (simulation test). Confirm the current fault code changes to a history fault and the system generates no new intermittent fault codes.
Real-World Cases
BYD DTC AI Analysis

C-pillar wiring harness chafing caused an intermittent short circuit

✓
A 2018 Qin EV450 had an intermittent SRS warning light on the instrument cluster. Read DTCs: B1712-00 (current) and B1712-00 (history). Removed the right C-pillar trim and found the airbag harness had chafed against the seatbelt anchor bolt, wearing through the insulation and causing intermittent contact with the chassis. Repaired the damaged harness using heat-resistant insulation tape and corrugated conduit as dual protection, then rerouted the harness away from sharp metal edges. No recurrence over three months of follow-up.
BYD DTC AI Analysis

Connector corroded and shorted after wading

✓
2019 model year E1. After the vehicle drove through water, the airbag warning light stayed on. The scan tool retrieved DTC B1712-00. The right curtain airbag connector measured 0.3Ω resistance to ground. Inspection found the connector seal below the right A-pillar had deteriorated; water ingress after the crossing caused electrolytic shorting between terminals. Repair: Replaced the connector assembly (including waterproof seal), dried the wiring harness, and replaced the SRS ECU (because water exposure may have damaged the internal sampling circuit). Total cost around 3,200 yuan.
BYD DTC AI Analysis

Airbag module internal short misdiagnosis case

✓
2017 BYD Qin 100. Set DTC B1712-00 after accident repair. An independent shop replaced the right curtain airbag, but the fault persisted. Detailed inspection revealed both old and new airbags were functional; the collision damaged the SRS ECU's internal driver chip, causing continuous low-impedance output. Testing with an airbag simulator confirmed the ECU fault. Replaced the airbag control module and recalibrated it to resolve the issue. Key lesson: Replacing the airbag without first using a simulator is blind parts swapping.
BYD DTC AI Analysis

改装导致的线束挤压故障

✓
用户改装顶棚氛围灯时，固定线束的卡钉刺穿了右侧帘式气囊线束的黄色护套，导致两根导线同时短路且对地短路。症状为改装后次日即亮气囊灯。维修时需更换整个顶棚线束总成（因气囊线束禁止接续），并告知用户私自改装导致安全气囊系统损坏，不在质保范围内。
BYD DTC AI Analysis

Phantom fault caused by software false positive

✓
2020 BYD E1. Intermittent DTC B1712-00 occurred on cold start and cleared itself once warm. Checked wiring harness and airbag measurements; both normal. Suspected SRS ECU software bug (sampling circuit drift at low temperatures in early software versions). Upgraded SRS control module software to V2.3.5, then monitored continuously for two weeks—no recurrence. These phantom faults are common in early BYD EV models; check the software version first.
Other Qin Plus 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.