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B167B11

DTC B167B11 has different definitions depending on the vehicle model — Seal 6 EV

Safety System

DTC B167B11 has different definitions depending on the vehicle model.

Early models, such as the BYD E2, E3, and Qin EV, define this fault as a short to ground in the right rear side impact sensor (SIS) signal circuit within the SRS airbag system.

Newer models, such as the Han EV, define it as a short to ground in the left front seat heater circuit.

Regardless of the application, sub-code '11' indicates a short to ground.

For the SRS system, this fault indicates the airbag control unit (ACU) continuously detects 0V on the right rear side impact sensor signal wire (below the 0.3V threshold), preventing the ACU from receiving the correct collision acceleration signal.

This triggers the SRS fail-safe mode, constituting a serious safety hazard.

The fault may prevent the side airbag or side curtain from deploying correctly during a side impact, or falsely trigger the airbag warning lamp while driving.

For the seat heater definition, this fault indicates the heating element circuit current increased abnormally, causing the control module to activate overcurrent protection.

The B167B11 fault code on the Seal 6 EV indicates a short to ground in the airbag side impact sensor or seat heater circuit, depending on model year. This high-severity fault risks airbag failure or heater malfunction. Common causes include chafed wiring or water corrosion. Visiting an authorised dealer is recommended; typical repair cost data is available from 4 recorded cases.
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Cases Logged
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Causes
Likely Causes — Seal 6 EV
  • 1Chafed right rear side impact sensor wiring harness insulation contacts body sheet metal or the seat frame, causing a short to ground (commonly occurs from improperly securing the harness after removing and installing the rear fender liner).
  • 2Water ingress and corrosion in the sensor connector causing the signal pin to short to ground (common after driving through water, car wash fluid residue, or seal ring aging).
  • 3Crash sensor internal electronic component failure causes a signal line short to ground (sensor internal capacitor breakdown or IC damage).
  • 4Seat slide rail, retaining screws, or clips pinched and damaged the wiring harness during removal or installation of the rear seat or C-pillar trim panel.
  • 5During rear fender accident repairs, a sheet metal edge cut the wiring harness, or damaged insulation at a mounting point caused a short to body ground.
What To Do
  • 1
    Safety preparation: Disconnect the battery negative terminal and wait at least 90 seconds to fully discharge the SRS system capacitor and prevent accidental airbag deployment. Wear an anti-static wrist strap.
  • 2
    Locate the sensor: Remove the right rear C-pillar trim panel and rear fender liner. Find the right rear side impact sensor (usually located above the rear sill beam, at the lower C-pillar, or behind the rear seat backrest).
  • 3
    Visual inspection: Check the sensor connector for looseness, water ingress, and corroded or bent pins. Inspect the wiring harness corrugated conduit for wear, chafing, or crush marks.
  • 4
    Circuit measurement: Use a multimeter to measure the resistance to ground of the sensor signal wire (usually the ACU 5V reference voltage circuit). The standard value must be greater than 10MΩ. A reading close to 0Ω confirms a short to ground.
  • 5
    Fault isolation: Disconnect the sensor connector. Measure the resistance to ground on both the wiring harness side (from the ACU) and the sensor side to determine whether the short circuit is in the wiring harness or internal to the sensor.
  • 6
    Wiring harness repair: If the wiring harness is damaged, cut out the damaged section. Re-solder or crimp new terminals. Apply dual-wall heat-shrink tubing (adhesive-lined) for waterproof insulation. Re-secure the wiring harness to prevent interference.
  • 7
    Component replacement: If the sensor is internally shorted, replace the right rear side impact sensor (Note: Use genuine parts. Typical installation torque is 8-10 N·m. Do not overtighten to prevent housing damage).
  • 8
    System verification: Restore connections, turn the power on, clear the fault code using the VDS diagnostic tool, and perform an SRS system self-check (static and dynamic road tests required). Confirm the fault code does not return and the airbag warning light turns off.
Real-World Cases
BYD DTC AI Analysis

BYD Song MAX left front heated seat failure (similar fault code B16A311)

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Symptoms: Dashboard displayed 'Seat system fault'. Left front seat heating failed; pressing the heater switch caused the indicator to flash for 3 seconds, then extinguish. Diagnosis: Scanned with VDS and retrieved B16A311 (Left front seat heater circuit short to earth). Measured heating pad resistance at 0.5 Ω (specification 2-5 Ω). Found the seat rail pinching the wiring harness, causing the heater element to short to earth. Fix: Replaced the left front seat heating pad assembly (S6J-6807100). Repaired and rerouted the wiring harness. Adjusted the seat rail stops.
Original source ↗
BYD DTC AI Analysis

BYD Qin Pro DM Seat Control Module Communication Fault (DTC B167111/B167B11)

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Symptoms: Instrument cluster intermittently displayed "Please check seat system", driver's electric seat adjustment occasionally failed, and seat memory positions were lost. The fault appeared easily on rough roads. Diagnosis: Read DTC B167111 (seat control module communication fault) and historical code B167B11. Measured CAN-H voltage to ground: 0.3V (standard 2.5-3.5V). Found the wiring harness retaining clip under the seat had detached; the harness rubbed against the seat rail and wore through, causing the CAN-H wire and heater power wire to short to ground simultaneously. Fix: Repaired the CAN-H and heater power wires, applied heat shrink tubing for waterproofing, replaced the wiring harness retaining clip, and recalibrated the seat memory positions.
Original source ↗
BYD DTC AI Analysis

BYD Tang DM front seat heating automatically turns off (DTC B168311)

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Symptoms: Heated seats switch off automatically after 3–5 minutes. The instrument cluster displays 'Seat Heating System Fault' and both front heated seats are inoperative. The vehicle had previously been driven through water. Diagnosis: Retrieved DTC B168311 (Right Front Seat Heater Circuit Short to Ground) and historical code B167B11. Inspected the seat heating control module (located beneath the right front seat) and found water staining and corrosion. Measured the resistance of the right front heating pad to ground at 0.2 Ω (short circuit); the left front reading was normal. Resolution: Replaced the right front seat heating pad and control module. Removed the seat, cleared accumulated water from the seat frame, and applied rust inhibitor. Checked the floor wiring harness for water exposure.
Original source ↗
BYD DTC AI Analysis

BYD Han EV heated seat low setting inoperative (DTC B167B11/B167C11)

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Symptoms: Left front seat heater only operates on the high setting; selecting low automatically reverts to off, with the climate panel displaying "Seat Fault". Diagnosis: Retrieved DTCs B167B11 (Left Front Seat Heater Circuit Short to Ground) and B167C11. Measured the low-setting heating element shorted to ground at 0.1 ohms; the high setting measured normal. Disassembly found the heating pad delaminated and aged, with the low-setting heating wire shifted and contacting the seat metal frame. The retention tape also deteriorated and detached from heat exposure. Resolution: Replaced the left front seat heating pad with an upgraded unit featuring optimised heating element retention, fitted a mica heat shield, and flashed the seat control module to software version 2023V03.
Original source ↗
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.