AU
B167D00

This DTC indicates the internal parameters of the right rear side impact sensor (typically located in the right C-pillar or rear door frame area for side impact detection) exceed the normal tolerance range or fail validation — Seal U

Safety System

This DTC indicates the internal parameters of the right rear side impact sensor (typically located in the right C-pillar or rear door frame area for side impact detection) exceed the normal tolerance range or fail validation.

Unlike a simple communication error, this fault confirms a normal communication link between the sensor and the SRS control module.

However, the sensor detected abnormal internal calibration data, sensitivity parameters, or zero-point offset during self-check.

Potential causes include corrupted internal sensor EEPROM data, physical characteristic drift from long-term use, A/D conversion errors resulting from unstable supply voltage, or internal accelerometer reference shift due to sensor installation stress deformation.

This fault prevents the SRS system from accurately determining right-side impact severity.

It may delay or incorrectly trigger the side airbag or side curtain airbag, severely compromising passive safety performance.

The system typically defaults to a degraded protection mode.

4
Cases Logged
5
Causes
Likely Causes — Seal U
  • 1Corrupted or missing internal sensor calibration data (EEPROM fault) causes parameter verification failure during self-test.
  • 2Sensor mounting bracket is loose, deformed, or exhibits stress concentration, causing a physical offset in the internal accelerometer reference.
  • 3Excessive voltage drop in the power supply circuit (contact resistance >1Ω) or poor ground, causing the operating voltage to fall outside the standard range of 5V±0.25V.
  • 4Backed-out terminals, oxidation, or water ingress at the harness connector causing signal interference or momentary voltage drop.
  • 5Installing a non-genuine sensor after a vehicle accident, failing to perform the calibration procedure, or internal wafer damage resulting from a severe impact to the sensor.
What To Do
  • 1
    Use the BYD VDS diagnostic tool to read the DTC freeze frame data. Record key parameters at the time of the fault, such as ambient temperature, battery voltage, and vehicle status, and confirm whether the fault is intermittent.
  • 2
    Disconnect the battery negative terminal, wait 3 minutes, then remove the right rear C-pillar interior trim panel. Visually inspect the crash sensor exterior for physical damage or cracks, verify the mounting bolt torque (standard is usually 8-10 N·m), and check the bracket for deformation.
  • 3
    Disconnect the sensor connector (usually 2-3 pins) and check the terminals for backed-out pins, corrosion, signs of water ingress, or green oxidation. Measure the supply voltage on the wiring harness side (should be 5V±0.25V) and the ground resistance (<1Ω).
  • 4
    Check the communication line (LIN line or CAN-H/L) between the sensor and the SRS module for continuity and insulation to ground/power. Verify there are no short or open circuits and that the waveform shows no abnormal distortion.
  • 5
    If circuit measurements are normal, reconnect the sensor, power on the vehicle, and perform the 'SRS System Calibration' or 'Crash Sensor Zero Point Calibration' function (use the original diagnostic tool; for some models, keep the vehicle stationary on a level surface for 3 minutes before calibration).
  • 6
    If calibration fails, will not execute, or the fault recurs, replace the right rear side impact sensor with an OEM part (verify the part number matches the vehicle model year). During installation, tighten strictly to the standard torque (9N·m) and avoid over-tightening.
  • 7
    After replacement, perform sensor initialization and calibration, clear the fault code, and conduct a road test (including rough roads and cornering). Read the data stream again to confirm the sensor parameters are within the normal range.
Real-World Cases
BYD DTC AI Analysis

Qin Pro DM right rear crash sensor loose mounting caused parameter drift

✓
2019 Qin Pro DM, airbag warning light constantly on. Retrieved DTC B167D00, could not clear. The owner said they had removed the right rear C‑pillar trim panel for an audio upgrade. Found the sensor mounting bolt hand‑tightened only, not to standard torque, and the weatherstrip misaligned, causing moisture inside. Removed the sensor and found slight oxidation on the mounting surface. Re‑tightened the sensor to 9 N·m torque, fixed the wiring harness waterproofing, and ran the sensor calibration procedure. Fault resolved.
Original source ↗
BYD DTC AI Analysis

E2 EV wiring harness pin backing out causing intermittent parameter error

✓
2020 E2. When driving on rough roads, the airbag warning light intermittently illuminated. The scan tool retrieved stored DTC B167D00. Inspected the right rear side impact sensor connector GJK08 (located at the right rear sill harness junction) and found pin 2 (power supply) had backed out 0.5 mm, causing supply voltage to fluctuate between 4.2–5.8 V, outside the sensor's normal operating range. Reseated the pin and applied conductive grease. Voltage measured stable at 5.02 V. Cleared the fault and road-tested for 20 km; the fault did not return.
Original source ↗
BYD DTC AI Analysis

Poor sensor grounding in the Qin EV causes internal AD conversion fault.

✓
2019 BYD Qin EV. After accident repairs to the right rear quarter panel, the vehicle continuously set DTC B167D00. The right side curtain airbag deployed during the collision. Replaced the right rear impact sensor with a brand new genuine unit, but the fault remained. A multimeter test showed the accident had damaged the sensor earth wiring harness, resulting in an earth resistance of 12Ω (spec: <1Ω). This caused the sensor's internal ADC reference voltage to drift. Re-routed the earth wire and connected it to the vehicle's main earth point G301. Earth resistance then measured 0.3Ω. Cleared the fault codes, the system returned to normal, and the data stream displayed normal sensor parameters.
Original source ↗
BYD DTC AI Analysis

E3 model sensor internal EEPROM low-temperature failure

✓
2020 model year E3. The owner reported the airbag warning light illuminated during winter morning startups and extinguished automatically after 10 minutes of driving. The diagnostic tool read current DTC B167D00. Reproduced the fault in a -5°C environmental chamber; the data stream showed the sensor temperature compensation parameters were out of tolerance. Found poor low-temperature characteristics in the sensor's internal memory chip. Replaced the right rear side impact sensor (part number SC-3636900). The fault did not recur during high/low temperature cycling tests from -20°C to 60°C.
Original source ↗
Other Seal U 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.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.B110AThis DTC indicates interrupted CAN bus communication or abnormal data between the air conditioning control unit (ACU) and the PM2.5 air quality sensor. The PM2.5 sensor monitors particulate concentration inside and outside the vehicle and provides the basis for purification control in the automatic air conditioning system. The ACU triggers this fault if it fails to receive a valid CAN message from the sensor within the specified period (usually 100-500 ms), if message verification fails, or if the signal frame times out. Although this fault does not affect vehicle driving safety, it disables the automatic air purification function. The air conditioning system cannot automatically switch between recirculation and fresh air modes or activate the air purification mode based on air quality. A persistent fault may restrict the thermal management strategy.
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.