AU
B1750

DTC B1750 indicates the SRS (Supplemental Restraint System) control unit detects an open circuit, abnormal resistance, or a physically missing Right Rear Side Airbag module — Qin Plus

Safety System

DTC B1750 indicates the SRS (Supplemental Restraint System) control unit detects an open circuit, abnormal resistance, or a physically missing Right Rear Side Airbag module.

This level 2 airbag system fault (a non-fatal hardware fault affecting passive safety functions) indicates the SRS control unit cannot establish normal communication with the right rear side airbag or detects infinite resistance in the airbag igniter circuit.

This fault prevents the right rear side airbag from deploying during a collision, severely compromising side-impact protection.

The instrument cluster continuously illuminates the airbag warning light.

Possible causes include an open circuit in the airbag module wiring harness, a loose connector, an open circuit in the internal airbag igniter, or incorrect airbag assembly installation following vehicle modification or repair.

The B1750 fault code on the Qin Plus indicates a medium-severity SRS fault involving the right rear side airbag. The control unit detects an open circuit, abnormal resistance, or missing airbag module, which may stop that airbag from deploying in a side impact. Common causes include a loose or oxidized connector and an open internal airbag squib. Visit an authorised dealer for inspection and repair. Typical repair cost data is available.
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Cases Logged
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Causes
Likely Causes — Qin Plus
  • 1Loose, oxidized, or poor contact at the right rear side airbag wiring harness connector (commonly at the yellow connector inside the C-pillar trim panel or under the seat)
  • 2Open circuit in the airbag module internal squib, or resistance out of standard range (normal: 1.8-2.5Ω; high or low values trigger a fault).
  • 3Wiring harness chafing or pinching at the door hinge, seat track, or body panel hole causes an open circuit (especially on vehicles with frequent seat adjustment or door operation).
  • 4Short or open circuit in the communication wiring harness between the SRS control unit and the airbag module (usually containing two ignition loop wires and one diagnostic wire).
  • 5Failure to install a genuine airbag module after accident repairs, or installation of a mismatched or previously deployed used airbag assembly.
What To Do
  • 1
    Safety preparation: Turn the vehicle OFF, disconnect the 12V battery negative terminal, and wait at least 3 minutes for the SRS system capacitor to fully discharge to prevent accidental airbag deployment.
  • 2
    Fault confirmation: Use the BYD VDS2000 or VDS1000 diagnostic tool to read all fault codes. Confirm only B1750 or related sub-codes (such as B1750-00) are present, and record the freeze frame data.
  • 3
    Physical inspection: Remove the right rear C-pillar interior trim panel (or seat backrest, depending on the airbag installation position). Verify the side airbag module is present and visually intact. Check that the yellow dedicated connector is fully seated and the locking tab is engaged.
  • 4
    Resistance measurement: Disconnect the airbag module connector. Use a multimeter to measure the resistance between the two terminals of the airbag squib. Standard value: 1.8-2.5 Ω. If the reading is OL (open circuit) or >10 Ω, replace the airbag module.
  • 5
    Harness continuity test: Measure wiring harness continuity between the airbag connector and the SRS control unit (usually located under the center console or in the front compartment). Carefully inspect the harness sleeve at the door hinges and seat slide rails for damage, and check for backed-out pins.
  • 6
    Insulation check: Measure the insulation resistance of the airbag wiring harness to ground and to power. The resistance must be >10MΩ to rule out a wiring harness short circuit.
  • 7
    Replacement verification: If the wiring harness is normal but resistance is abnormal, replace the right rear side airbag module with an OEM part (part number must match vehicle model year) and reconnect the battery.
  • 8
    System reset: Clear the fault code and cycle the ignition switch three times. Confirm the SRS system passes the self-check and the instrument warning light turns off. Read the data stream with the diagnostic tool to confirm the airbag status displays as 'Normal'.
Real-World Cases
BYD DTC AI Analysis

Oxidised right rear airbag connector caused DTC B1750 in BYD Song MAX

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Symptoms: Three years after purchase, the airbag warning light on the instrument cluster illuminated intermittently. It sometimes went off after restarting but eventually stayed on. Diagnosis: Used VDS2000 to retrieve DTC B1750 (right rear side airbag not present). Live data showed infinite resistance on this airbag circuit. Removed the right C-pillar trim and found white oxidation on the pins inside the yellow airbag harness connector. The connector locking tab was not fully engaged, likely caused by a previous audio system modification. Repair: Cleaned the connector pins with electronic contact cleaner, applied conductive grease, and reconnected the harness, making sure the locking tab engaged fully. Measured resistance recovered to 2.0Ω. Cleared the DTC and monitored the vehicle for one month. No recurrence.
BYD DTC AI Analysis

BYD Tang DM seat rail chafing wiring harness causing intermittent B1750

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Symptoms: While driving on rough roads, the airbag warning light occasionally flickered. The dealership inspected the vehicle multiple times without identifying the cause. Diagnostic Process: Retrieved intermittent fault code B1750. Inspected the airbag wiring harness beneath the right rear seat and found the harness had chafed at the seat rail mounting point, wearing through the insulation and partially fracturing the copper strands. Vibration caused momentary open circuits. Resolution: Repaired the harness by cutting out the damaged section, soldering the wires and insulating with heat-shrink tubing. Rerouted the wiring to clear the seat rail travel path and secured it with cable ties to the body wiring channel. Fault permanently resolved.
BYD DTC AI Analysis

Incorrect airbag module model after accident repair caused B1750 in BYD Yuan EV

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Symptoms: After a side impact, a non-authorised repairer replaced the right rear side airbag, but the instrument cluster kept displaying an airbag fault. Diagnosis: Retrieved DTC B1750. The new airbag's resistance measured normal, but VDS showed the airbag configuration code did not match the vehicle VIN. Inspection found the repairer had fitted an airbag module from a lower-spec variant (without side airbag) or used a previously deployed part. Repair: Ordered a genuine right rear side airbag module matching the vehicle specification (with correct resistance and recognition resistor). Installed it and performed SRS coding with VDS. Fault cleared.
BYD DTC AI Analysis

BYD Qin Pro SRS control unit software falsely reporting B1750

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Symptoms: The vehicle had no collision or modification history. The airbag warning light suddenly came on with DTC B1750. Diagnosis: Checked the wiring harness connectors – undamaged. Measured airbag resistance at 2.2Ω (normal). Wiggled the harness, but the fault did not reappear. Reviewed the BYD technical bulletin and found a software bug in the SRS control unit for this production batch that can falsely report an "airbag not present" fault during voltage fluctuations. Repair: Updated the SRS control unit software with VDS1000 from version V1.2 to V1.4. Cleared fault codes after the update. The fault has not returned.
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.