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B1763

DTC B1763 indicates the airbag control unit (SRS ECU) detects a 0 Ω (or near 0 Ω) resistance in the right front curtain shield airbag igniter circuit — Qin Plus

Safety System

DTC B1763 indicates the airbag control unit (SRS ECU) detects a 0 Ω (or near 0 Ω) resistance in the right front curtain shield airbag igniter circuit.

Normal airbag igniter resistance is 2.0-5.0 Ω.

A 0 Ω resistance indicates a short in the igniter circuit.

Possible causes include an internal igniter short, a wiring harness short to ground (GND) or power (B+), or a faulty SRS ECU internal drive circuit.

This fault causes the SRS system to enter fail-safe mode.

During a collision, the affected curtain shield airbag may fail to deploy.

The instrument panel SRS warning light illuminates continuously to indicate limited occupant protection system functionality.

The B1763 fault code on the Qin Plus indicates a short circuit in the right front curtain shield airbag igniter circuit, with resistance near 0 Ω instead of the normal 2.0–5.0 Ω. Severity is medium because the SRS may enter fail-safe mode and the curtain airbag may not deploy in a crash. Common causes include a shorted airbag igniter or damaged wiring in the A-pillar/headliner area. Visit an authorised dealer for diagnosis and repair. Typical repair cost data is available.
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Cases Logged
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Causes
Likely Causes — Qin Plus
  • 1Internal short circuit in the right front side curtain airbag igniter: Manufacturing defects, aging, or prolonged vibration cause the igniter bridge wire inside the airbag module to break and short together.
  • 2Physical damage to the wiring harness: Wiring harnesses in the A-pillar trim, headliner, or floor wear during accident repairs, modifications (such as routing a dash cam cable), or long-term use, damaging the wire insulation and causing a short to ground or short to power.
  • 3Connector fault: Water ingress, oxidation, corrosion, or terminal deformation at the airbag wiring harness connector located inside the right front door sill trim panel or below the A-pillar causes a short circuit between pins.
  • 4Internal SRS ECU fault: Damage to the airbag control unit internal driver chip or sampling circuit generates a false short circuit fault.
  • 5Improper repair procedures: failing to disconnect the 12V battery negative terminal as specified during previous repairs, directly measuring the airbag circuit with a multimeter on the resistance setting (use a dedicated airbag resistor), or electrostatic discharge causing an igniter short circuit.
What To Do
  • 1
    Safety preparation: Set the vehicle to OFF, disconnect the 12V battery negative terminal, and wait at least 90 seconds to fully discharge the SRS ECU backup power supply and prevent accidental airbag deployment during repair.
  • 2
    Fault confirmation and freeze frame analysis: Connect the diagnostic tool to read the DTC B1763 freeze frame data. Record the vehicle speed, temperature, voltage, and other environmental conditions present when the fault occurred to determine if the fault is intermittent or continuous.
  • 3
    Visual inspection: Remove the right A-pillar trim, headliner edge, and right front door sill trim. Inspect the curtain airbag wiring harness connector (usually a yellow plug) for looseness, water ingress, burn damage, or aftermarket wire taps.
  • 4
    Harness continuity test: Disconnect the SRS ECU connector and the right front curtain airbag connector. Use a multimeter to measure resistance to ground and resistance to power at the harness-side terminals (SRS side and airbag side). The standard value must be greater than 1 MΩ. Measure harness continuity to confirm no short to ground or power.
  • 5
    Airbag module isolation test: Connect the dedicated airbag substitute resistor (2.0Ω) to the circuit in place of the right front curtain airbag. Connect the battery negative terminal, clear the fault code, and power on for a self-check. If the fault code disappears, the airbag inflator has an internal short circuit; replace the right front curtain airbag assembly. If the fault code remains, the fault lies in the wiring harness or ECU.
  • 6
    SRS ECU inspection: Check the ECU connector pins for corrosion or push-back. Measure the resistance of the corresponding internal drive port of the ECU. Update the SRS control unit software or replace the ECU if necessary.
  • 7
    Repair and Verification: After repairing or replacing the faulty component, reconnect all connectors and connect the battery negative terminal. Clear the DTC using the diagnostic tool and perform an SRS system self-check (with the steering wheel centered and the vehicle level). Finally, perform a road test to verify the SRS warning lamp turns off and no new fault codes appear.
Real-World Cases
BYD DTC AI Analysis

Song MAX right front curtain airbag short circuit after water ingress

✓
A 2019 Song MAX came in with the SRS light on after driving through heavy rain. DTC B1763 stored. Removed the right front A-pillar trim. Found the airbag circuit pins in the sill harness connector corroded from water ingress due to poor sealing, shorting the terminals (0.3Ω). Cleaned the connector with electronic contact cleaner, blew it dry, applied conductive grease, and replaced the waterproof seal. Fault cleared. Analysis: On flood-damaged vehicles, check the sealing of SRS harness connectors mounted low on the floor.
BYD DTC AI Analysis

Qin Pro modifications caused wiring harness chafing and short circuit

✓
The owner of a 2020 Qin Pro reported the SRS warning light illuminated with DTC B1763. Upon inquiry, the owner had recently installed a 360-degree camera system with wiring routed through the right-hand A-pillar. Inspection found the installer had pierced the factory SRS wiring harness insulation when securing cable clips, causing the airbag igniter wire to short to ground. Repaired damaged wiring using double-layer heat-shrink tubing, rerouted the harness to avoid sharp metal edges, cleared fault codes and restored normal operation. Note: Modifications involving the A-pillar or headliner require extra care to protect SRS wiring.
BYD DTC AI Analysis

Replaced airbag assembly due to internal short in igniter

✓
Case involves a 2019 BYD Song MAX with no accident history or modifications. After 30,000 km, the SRS warning light illuminated intermittently with DTC B1763. Disconnected the right-side roof curtain airbag connector and measured 0.1Ω across the airbag terminals (normal ~2.5Ω), indicating an internal short in the squib. Replaced the right front side curtain airbag assembly (requires headliner removal). Fault cleared. Root cause: Suspected moisture contamination of the propellant or a manufacturing defect caused the bridge wire to melt and short.
BYD DTC AI Analysis

SRS ECU false positive software fault

✓
A 2020 Qin petrol variant set a B1763 fault code. Airbag resistance and wiring harness measured normal. Consulted BYD TSB: early-batch SRS control unit software has a sampling error that triggers false short-circuit faults below 0°C. Fix: Updated SRS ECU software using VDS2000/3000 (version must be above V2.3). Fault has not returned since. Note: For short-circuit fault codes with normal measured values, suspect an ECU software bug.
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.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.B110BDTC B110B indicates a fault in the internal air pump (sampling pump) of the PM2.5 air quality detector. This pump draws cabin or outside air into the PM2.5 sensor detection chamber, enabling the laser scattering sensor to measure real-time particulate matter concentration. The air conditioning controller (or BCM) sets this DTC upon detecting an open or short circuit in the pump drive circuit, or abnormal current caused by a seized pump motor. This fault disables the "Green Clean" system, causes the instrument cluster air quality display to read abnormally or disappear, and disables the automatic fresh air/recirculation switching function. It does not affect the vehicle powertrain or core thermal management functions.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.B173BDTC B173B indicates an abnormal electric A/C compressor speed feedback signal or a communication fault between the compressor controller and the motor. In BYD new energy models (e.g., Tang, Song, Qin, and Yuan series), this DTC belongs to the HVAC subsystem within the Body Control system and specifically involves the electric compressor closed-loop control circuit. The ECU sets this DTC when the compressor controller (IPM) fails to receive a valid pulse signal from the Hall speed sensor for more than 3 continuous seconds, or when the deviation between the detected actual speed and the target commanded speed exceeds the calibrated threshold (typically >500 rpm). This fault forces the A/C system into fail-safe mode and stops compressor operation. Symptoms include a complete lack of cooling, intermittent cooling, or a sharp decrease in cooling performance. The instrument cluster A/C warning lamp may also illuminate. Prolonged operation with this fault can degrade high-voltage system insulation or cause controller overcurrent damage.
Common problems reported for Qin Plus →Qin Plus 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.