AU
B17141B

DTC B17141B indicates the right curtain airbag ignition circuit resistance exceeds the normal threshold set by the SRS control module (typically 3 — Qin Plus

Safety System

DTC B17141B indicates the right curtain airbag ignition circuit resistance exceeds the normal threshold set by the SRS control module (typically 3.0-5.0Ω, depending on vehicle calibration).

This active SRS system fault means the right curtain airbag may fail to deploy or experience delayed deployment during a collision.

Excessive resistance usually indicates a high-resistance point in the ignition circuit.

Potential causes include poor wiring contact, connector oxidation or corrosion, a partially broken wiring harness, or an internal open circuit in the curtain airbag module.

This fault illuminates the SRS warning light continuously and forces the system into degraded mode.

Extreme cases may compromise side-impact protection.

5
Cases Logged
5
Causes
Likely Causes — Qin Plus
  • 1Loose or oxidized right C-pillar/D-pillar curtain airbag connector: Long-term vehicle vibration loosens the connector, or pin oxidation after wading increases contact resistance.
  • 2Roof side rail internal wiring harness chafed and broken: Prolonged bending of the curtain airbag wiring harness at the door seal or A-pillar/C-pillar routing hole partially breaks the copper strands, creating high resistance.
  • 3Right curtain airbag module internal open circuit: A broken bridge wire inside the curtain airbag inflator or damp propellant causes an abnormal increase in resistance.
  • 4SRS ECU internal detection circuit fault: Control module internal sampling resistor or ADC circuit malfunction, falsely reporting high curtain airbag resistance.
  • 5Harness shorting bar not fully disengaged: When reconnecting the connector during repair, the shorting bar fails to fully spring open, increasing series resistance.
What To Do
  • 1
    Safety preparation: Disconnect the 12V battery negative terminal and wait at least 90 seconds (some models require 180 seconds) to fully discharge the SRS capacitor and prevent accidental airbag deployment.
  • 2
    Read data stream: Use VDS or Launch X-431 to read the SRS data stream. Record the current curtain airbag resistance value and historical freeze frame data to confirm if the fault is intermittent.
  • 3
    Visual inspection: Remove the right C-pillar trim panel and headliner edge. Inspect the curtain airbag module connector (usually a yellow plug) for looseness, water ingress, or pin oxidation.
  • 4
    Resistance measurement: Remove the battery negative cable and short it to the body ground to discharge static electricity. Disconnect the curtain airbag module connector. Connect a 2.0 Ω dedicated jumper resistor to the connector side (not the module side). Read the SRS data stream to confirm the resistance returns to normal. This determines whether the fault is in the module or the wiring harness.
  • 5
    Harness continuity test: Use a multimeter to measure the continuity resistance of the curtain airbag harness from the connector to the SRS ECU. Normal resistance is less than 1.0 Ω. If resistance exceeds 1.5 Ω, check the intermediate connector (usually in the right B-pillar or floor harness).
  • 6
    Insulation check: Measure the insulation resistance between the curtain airbag wiring harness and body ground. Resistance must be greater than 1 MΩ to prevent hidden short circuits from causing abnormal resistance.
  • 7
    Component replacement: If the wiring harness is normal but the curtain airbag module resistance is abnormal (usually greater than 8Ω or infinite), replace the right-side curtain airbag module (simultaneously install new fixing clips and T-bolts).
  • 8
    System calibration: After replacement, perform 'SRS System Configuration' and 'Curtain Airbag Resistance Learning' (required on some newer models). Clear fault codes and perform a crash simulation test (use a dedicated resistance simulator to verify circuit integrity).
Real-World Cases
BYD DTC AI Analysis

Qin Pro DM: SRS warning light on after wading through water, right curtain airbag resistance abnormal

✓
2019 BYD Qin Pro DM. Airbag warning light stayed on after the vehicle drove through water. Scan tool read DTC B17141B. Live data showed right curtain airbag resistance 6.8 Ω (specification 2.0–3.5 Ω). Teardown found water inside the right C-pillar curtain airbag connector, with oxidized and blackened pins. Cleaned the pins with electronic contact cleaner, applied conductive grease, and reconnected the connector. Resistance returned to 2.4 Ω. Cleared the DTC; fault resolved. Recommend inspecting the door seals and applying waterproofing treatment.
BYD DTC AI Analysis

False high-resistance warning for curtain airbag after accident repair

✓
2018 Qin Pro petrol. After right-side accident repairs, DTC B17141B kept setting. Found the technician replaced the curtain airbag without removing the old T-bolt, so the new airbag connector could not seat fully. The internal shorting bar did not fully release, causing about 4 Ω contact resistance. Removed the airbag, extracted the old bolt, and fully locked the connector (heard the second click). Resistance returned to normal. Always use new fixing bolts when replacing curtain airbags.
BYD DTC AI Analysis

Wiring harness aged and broken, causing intermittent fault

✓
2019 BYD Qin Pro. SRS warning lamp illuminated intermittently, and DTC B17141B appeared as a history code. Static resistance tested normal but fluctuated during rough-road testing. Removed the roof rail trim and found the curtain airbag wiring harness insulation worn through at the B-pillar grommet, with only 2–3 copper strands remaining connected. Cut out the damaged section, soldered in an extension wire, and sealed with dual-wall heat shrink tubing. Rerouted the harness to avoid contact with metal edges. Fault completely resolved.
BYD DTC AI Analysis

Aftermarket curtain airbag module compatibility fault

✓
After fitting a non-genuine right-hand side curtain airbag to a 2018 BYD Qin Pro DM, DTC B17141B set. The new airbag's resistance measured 5.2Ω, exceeding the BYD SRS ECU calibration limit of 4.5Ω. Fitted a genuine replacement (2.8Ω) and the fault cleared. The aftermarket part's bridge wire material or diameter difference caused the higher base resistance. Use only genuine parts for airbag systems to keep resistance values within the ECU's recognition range.
BYD DTC AI Analysis

SRS ECU internal sampling circuit fault misdiagnosis

✓
Multiple models logged DTC B17141B. Replaced the curtain airbag and wiring harness, but the fault persisted. Used an oscilloscope to check the SRS ECU curtain airbag drive terminal waveform and found abnormal sampling voltage. Replaced the SRS control module (requires reprogramming the VIN and configuration codes) and resolved the fault. An aging precision resistor inside the ECU caused the resistance sampling reference to shift. This is a rare case; rule out all wiring faults before considering this.
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.