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 — Atto 3

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.

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Cases Logged
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Causes
Likely Causes — Atto 3
  • 1Right rear side airbag wiring harness connector loose, oxidized, or making poor contact (commonly the yellow connector inside the C-pillar trim panel or under the seat)
  • 2Airbag module internal igniter open circuit or resistance out of standard range (Normal: 1.8-2.5 Ω; excessively high or low values trigger the fault).
  • 3Wiring harness chafing or pinching at the door hinge, seat track, or sheet metal 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).
  • 5Non-genuine airbag module installed after accident repairs, or a mismatched or previously deployed used airbag assembly installed.
What To Do
  • 1
    Safety preparation: Set the vehicle to OFF, disconnect the 12V battery negative terminal, and wait at least 3 minutes to fully discharge the SRS system capacitor and prevent accidental airbag deployment.
  • 2
    Fault confirmation: Use the BYD VDS2000 or VDS1000 diagnostic tool to read the complete 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 airbag installation position). Check if the side airbag module is present and intact. Verify the yellow dedicated connector is fully inserted 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 inflator. The standard value is 1.8-2.5Ω. If the multimeter reads OL (open circuit) or >10Ω, 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 centre console or in the front compartment). Inspect the harness sheath at the door hinges and seat slide rails for damage, and check for backed-out terminals.
  • 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 OEM right rear side airbag module (part number must match vehicle model year) and reconnect the battery.
  • 8
    System reset: Clear the fault code, cycle the ignition switch three times, confirm the SRS system self-check passes and the instrument warning light turns off. Use the diagnostic tool to read the data stream and confirm the airbag status displays '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 Atto 3 Fault Codes
P0A0DBattery Energy Control Module Requested MIL IlluminationP0AA6Hybrid Battery Voltage System Isolation FaultP1A00Drive Motor "A" Performance — BYD proprietaryB1108For 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.
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.