AU
B1752

DTC B1752 indicates a short circuit to battery positive (B+) in the RHS Rear Side Airbag squib circuit — Seal 6 EV

Safety System

DTC B1752 indicates a short circuit to battery positive (B+) in the RHS Rear Side Airbag squib circuit.

In the Supplemental Restraint System (SRS), normal airbag inflator resistance is 2-3 ohms.

The control unit determines circuit status by monitoring circuit current and voltage drop.

When wiring harness insulation damage causes a short to the 12V power supply wire, the control unit detects an abnormally high potential (near battery voltage) and triggers DTC B1752.

This fault causes the system to disable the affected airbag (fail-safe mode), preventing deployment during a collision.

Additionally, continuous current creates a risk of unintended airbag deployment.

The system classifies this as a level 3 severe fault.

The B1752 fault code on the Seal 6 EV indicates a high-severity short to battery positive in the right rear side airbag squib circuit. This can disable that airbag and may create a risk of unintended deployment. Common causes include worn wiring in the right B-pillar/seat area or water ingress at the under-seat connector. The recommended fix is to visit an authorised dealer for SRS diagnosis and repair. Typical repair cost data is available.
5
Cases Logged
5
Causes
Likely Causes — Seal 6 EV
  • 1Worn wiring harness inside the right B-pillar trim: Frequent rear passenger entry and exit or seat adjustment wears through the harness sleeve between the B-pillar and the seat, shorting the copper wire to the body power wire.
  • 2Water ingress into the connector under the seat: During vehicle wading or interior cleaning, water seeps into the airbag wiring harness connector under the right rear seat, causing a short circuit or conductive corrosion between terminals.
  • 3Airbag module internal fault: Abnormally low igniter resistance or an internal short circuit in the right rear side airbag assembly causes abnormal circuit resistance.
  • 4Harness damage after accident repair: A previous right-side collision or repair pinched the wiring harness in the B-pillar, sill, or C-pillar area against harness clips or sharp metal edges, damaging the insulation.
  • 5Internal drive circuit fault in the SRS control unit: A damaged ignition driver chip or monitoring circuit inside the airbag control module falsely reports a short to power.
What To Do
  • 1
    Safety preparation: Disconnect the 12V battery negative terminal and wait at least 90 seconds to ensure the SRS capacitor discharges completely. Wear an anti-static wrist strap. Do not use radio equipment near the airbag assembly.
  • 2
    Initial diagnosis: Use a Launch X-431 or BYD dedicated diagnostic tool to read all SRS fault codes, check for B1752 and any accompanying fault codes (such as B1751 short to ground), and record the freeze frame data.
  • 3
    Visual inspection: Remove the right B-pillar lower trim panel, right rear door sill trim panel, and right rear seat. Inspect the wiring harness for damage or burn marks. Focus on movement interference points between the seat and the B-pillar.
  • 4
    Electrical measurement: Disconnect the airbag control unit connector (note the shorting bar). Use a multimeter to measure the voltage to ground for the right rear side airbag circuit (usually the corresponding connector pins). Normal voltage is less than 1V. A 12V reading confirms a short to power.
  • 5
    Section isolation: Disconnect the right rear side airbag module connector and measure the wiring harness side and the airbag side separately: if the wiring harness side still has 12V, the fault is in the wiring harness; if the wiring harness side is normal and the airbag side is shorted, replace the airbag module.
  • 6
    Wiring harness repair: If the wiring harness is damaged, repair it using waterproof heat-shrink tubing or replace the wiring harness assembly. Route the harness away from seat slide rails and sharp metal edges, and resecure the retaining clips.
  • 7
    Component test: After repair, reconnect all connectors. Use the diagnostic tool to perform the 'Airbag System Function Test' or 'Actuator Test'. Confirm B1752 becomes a history fault code and clears successfully.
  • 8
    Final verification: After clearing the fault code, road test the vehicle. Perform multiple ignition cycles to confirm the fault code does not recur. Verify the SRS warning light turns off normally.
Real-World Cases
BYD DTC AI Analysis

Song MAX: Right rear seat adjustment chafing B-pillar wiring harness

✓
A 2019 Song MAX with 32,000 km had the SRS warning light staying on. Retrieved DTC B1752. Removing the right B-pillar trim revealed the airbag harness sheath at the gap between the seat frame and B-pillar inner lining had worn through, caused by frequent second-row seat adjustments. The exposed copper wires shorted directly to the vehicle power wiring. Repair: Replaced the B-pillar-to-seat wiring harness assembly (part number 4G-5826934), added rubber protective sleeves and cable ties at wear points, and rerouted the harness away from moving parts. The repair cleared the fault. No recurrence at three-month follow-up.
BYD DTC AI Analysis

Tang DM airbag connector corroded and shorted after water wading.

✓
2021 Tang DM drove through standing water after heavy rain. The next day, the dashboard displayed 'Check Airbag System'. The scan tool retrieved codes B1752 and B1751 (short to ground). Inspection found the right rear carpet wet. Removing the airbag connector (yellow plug) under the seat revealed mud and water inside; electrolytic corrosion between the terminals created a conductive path. Cleaned the connector with anhydrous alcohol, dried it with compressed air, applied conductive grease, and replaced the waterproof seal. Also checked the sunroof drain tube for blockages to prevent further water ingress. After clearing the codes, the system returned to normal.
BYD DTC AI Analysis

Yuan EV wiring harness pinched after accident repair, causing short circuit

✓
A 2019 BYD Yuan EV sustained minor collision damage to the right rear side. Following repairs at an independent workshop, DTC B1752 appeared. Inspection at the dealer revealed that during installation of the B-pillar trim, the technician had trapped the airbag wiring harness between the metal clip and plastic trim panel. Long-term compression damaged the insulation, allowing the harness copper wires to contact the body's 12V constant power wire. Solution: Repaired the damaged harness section, rerouted the wiring to avoid running parallel to the power wire, wrapped it with fleece tape, and installed the trim clips to standard torque. Recoded and calibrated the airbag control unit.
BYD DTC AI Analysis

Internal short circuit in right rear side airbag module (Qin Pro)

✓
A 2020 BYD Qin (petrol) flagged a B1752 fault code. After disconnecting the airbag module connector, the harness side measured normal (no short to power), but the airbag module pins measured 0.5 ohms (normal range: 2-3 ohms). This indicated an internal igniter short in the airbag assembly. Replaced the right rear side airbag module (part number SCE-5826910) and the fault cleared. The cause: either the propellant inside the airbag had become damp or a manufacturing defect caused insulation failure between the igniter terminals.
BYD DTC AI Analysis

Intermittent fault caused by SRS control unit false alarm

✓
A 2019 Tang intermittently set B1752 on cold starts; the code cleared once warm. The wiring harness tested normal for continuity and insulation. Airbag circuit voltage measured an abnormal 12V during the fault. Inspection revealed slight oxidation on the SRS control unit (ACU) connector pins, causing reference voltage drift in the monitoring circuit. Cleaning the connector, applying electronic contact cleaner, and upgrading the ACU software from V2.1 to V2.3 to optimize the ignition circuit monitoring threshold resolved the issue. The fault has not returned.
Other Seal 6 EV 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.B1737DTC B1737 indicates the Supplemental Restraint System (SRS) detected abnormal continuity between the right middle-row side airbag squib circuit (typically the second-row right seat side airbag or right curtain airbag) and the vehicle power supply (B+, battery positive). The SRS ECU monitors the airbag inflator resistance via an internal current source (normal resistance: 2.0–3.0 Ω). If the ECU detects the voltage across the inflator circuit remaining close to battery voltage (>5 V and approaching 12 V) instead of the expected low potential or floating state, it identifies a short to power. This fault prevents the airbag from deploying normally during a collision because the short circuit bypasses the firing current. In extreme cases, abnormal current can cause unintended deployment, posing a severe safety hazard.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 Seal 6 EV →Seal 6 EV 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.