AU
B167200

DTC B167200 indicates the airbag system (SRS) detects a mismatch between the configuration parameters of the Right Side Impact Sensor (typically mounted inside the right B-pillar) and the calibration data stored in the SRS control module — Atto 8

Safety System

DTC B167200 indicates the airbag system (SRS) detects a mismatch between the configuration parameters of the Right Side Impact Sensor (typically mounted inside the right B-pillar) and the calibration data stored in the SRS control module.

This is not a basic circuit continuity fault; it involves sensor ID recognition failure, hardware parameter verification errors, or lost/corrupted software configuration data.

In the BYD architecture, this sensor monitors lateral acceleration changes and provides critical data for side airbag and side curtain airbag deployment decisions.

This fault forces the SRS into a degraded mode.

The right side airbag and side curtain airbag may fail to deploy during a collision.

Additionally, the system may send an abnormal crash signal via a hardwired connection to the BMS and Vehicle Control Unit (VCU), triggering high-voltage system power cut-off protection or a reduced power mode.

5
Cases Logged
5
Causes
Likely Causes — Atto 8
  • 1Poor contact or terminal back-out at the sensor wiring harness connector: The right side impact sensor is located on the B-pillar. Long-term vibration or a loose connection causes internal connector terminals to oxidize or back out, resulting in intermittent signal interruption or abnormal resistance values and triggering a configuration verification failure.
  • 2SRS control module software defect or calibration data loss: Early-batch SRS module software versions contain bugs, or the module loses stored sensor ID matching data and calibration parameters during vehicle power loss or low battery voltage.
  • 3Sensor hardware fault: Damage to the internal MEMS accelerometer or ASIC chip causes output signal parameters to exceed the SRS module tolerance range.
  • 4Sensor calibration not performed after accident repair: After a vehicle collision, the technician installed a new side impact sensor but did not use the dedicated diagnostic tool to perform the sensor online matching (ID matching) and zero-point calibration procedures.
  • 5Wiring harness short/open circuit or electromagnetic interference: The sensor power supply circuit (5V reference voltage), CAN communication line, or hardwired signal line has an intermittent short circuit, or shares a ground point with high-power equipment such as the rear wiper, causing voltage fluctuations.
What To Do
  • 1
    Initial diagnosis: Connect the VDS2000 or BYD dedicated diagnostic tool. Access the SRS system to read the complete fault codes. Confirm if B167200 is a current or history code. Read the data stream to check the right side impact sensor status (should display 'Normal' or a specific voltage value). Check for other related fault codes (e.g., B165700, B17A400).
  • 2
    Physical inspection and cleaning: Disconnect the negative battery terminal, wait 3 minutes, then remove the right B-pillar lower trim panel. Locate the right side impact sensor (usually a black square component with a 2-3 pin connector). Check the connector for looseness, water ingress, or oxidation. Unplug the connector and check the terminals for recession or deformation. Clean with electrical contact cleaner and apply conductive grease.
  • 3
    Circuit measurement: Use a multimeter to measure the sensor connector power supply terminal (expect a 5V ± 0.25V reference voltage), ground terminal (resistance to ground < 1Ω), and signal wires (CAN-H approx. 2.6V, CAN-L approx. 2.4V; hardwire signal voltage varies by vehicle model). Measure continuity between the wiring harness and the sensor body. Check for short to ground or short to power.
  • 4
    Sensor swap test (if applicable): If the vehicle has symmetrical left and right side impact sensors, power off the vehicle and swap the left and right sensor connectors. Power the vehicle back on and read the fault codes. If the fault code follows the sensor to the left side (changes to B167100), the sensor is faulty. If the fault code remains B167200, the wiring harness or SRS module is faulty.
  • 5
    Software processing and calibration: Check the SRS control module software version. Update to the latest version if available. Clear all fault codes, then execute the 'SRS system self-learning' or 'crash sensor calibration' procedure (using a diagnostic tool, follow the prompts to complete sensor ID matching and zero-point calibration). On some models, tap the vehicle body near the sensor during calibration to simulate a slight vibration and confirm the signal.
  • 6
    Verification and road test: After completing calibration, confirm the instrument cluster SRS warning lamp is off. Read the data stream to confirm the right side impact sensor status displays 'Normal'. Conduct a road test, focusing on bumpy roads, to confirm the fault does not recur. Finally, check the vehicle high-voltage system status to ensure no power-limited mode is active.
Real-World Cases
BYD DTC AI AnalysisFrom Chinese market (translated)

BYD E2 intermittent SRS warning light with high-voltage system alarm

✓
2019 BYD E2, 30,000 km. Owner reported the SRS warning light flickering intermittently, especially on rough roads, along with occasional 'Power System Fault' warnings. Scan tool showed active DTC B167200 (Right Side Impact Sensor Parameter Error) and stored DTC B165700 (Left Front Impact Sensor Configuration Error). The vehicle controller logged B17A400 (SRS Hardwire Signal Abnormal), and the BMS stored P1A5100 (Collision Hardwire Signal Abnormal). Removed the right B-pillar trim and inspected the right side impact sensor connector. Found the internal terminals oxidised and retracted 0.5 mm; contact resistance measured 3.2 Ω (spec <0.5 Ω). Repaired the terminals with a dedicated terminal removal tool, cleaned the connector, applied conductive paste, and reconnected it. Cleared the DTCs and performed the SRS system self-learning procedure. Fault resolved.
Original source ↗
BYD DTC AI AnalysisFrom Chinese market (translated)

BYD Song MAX DM-i: Wiper triggers SRS and power limit fault

✓
2022 Song MAX DM-i. The customer reported that when operating the rear wiper, the dashboard suddenly displayed a "Power Limited" warning and the SRS warning light illuminated, and the vehicle entered limp mode. A VDS scan revealed B167200 series fault codes stored in the SRS system. Analysis of the wiring diagram showed the rear wiper motor and SRS control module share earth point G09 (located below the left C-pillar). Inspection of G09 found the mounting bolt had loosened, causing common-mode voltage interference when the wiper motor operated, which affected the SRS module's reading of the right side impact sensor signal. Repair procedure: Tightened the G09 earth point to standard torque (10 N·m), checked the rear wiper wiring shield earthing, cleared the fault codes, and road tested. Operating the wiper no longer triggers the fault, and the SRS system operates normally.
Original source ↗
BYD DTC AI AnalysisFrom Chinese market (translated)

BYD E2/Qin Pro Series Collision Sensor Configuration Error Technical Bulletin

✓
Batch issue notification for 2018–2020 Qin Pro, 2019 E2, and similar models. After 1–2 years of operation, the instrument cluster SRS warning lamp illuminates intermittently on some vehicles. Diagnostics show DTC B167200 (right side impact sensor configuration error), sometimes with B167100. Factory technical analysis identified two root causes: 1) Batch-related design tolerances in the right side impact sensor wiring harness connector terminals make them prone to retraction after extended use. 2) The sensor ID matching algorithm in early SRS control module software version V1.2 contains a defect. Repair procedure: Replace the wiring harness connector with an improved version featuring a secondary locking mechanism. Upgrade the SRS module to software version V1.4 or later. Perform the sensor online calibration routine and rewrite the sensor configuration parameters. Enter the 14-digit ID code located on the sensor housing.
Original source ↗
BYD DTC AI AnalysisFrom Chinese market (translated)

Uncalibrated right side impact sensor after accident repair caused B167200.

✓
2019 BYD Qin Pro DM. Following a right-side collision, a general repair shop replaced the right front fender and right side impact sensor, but after the repair the SRS warning light stayed illuminated on the dash. The scan tool showed DTC B167200, which could not be cleared. Inspection found that although the technician had installed an OEM sensor, they did not perform the collision sensor replacement matching procedure using the diagnostic tool. The SRS control module still held the old sensor's ID and zero-point data, so it did not match the new sensor. Solution: Access the SRS special functions menu, select 'Collision Sensor Calibration', enter the new sensor ID when prompted (the ID is under the QR code on the sensor body), then complete the horizontal zero-point calibration and sensitivity test. The fault code cleared automatically.
BYD DTC AI AnalysisFrom Chinese market (translated)

BYD Dolphin right-side impact sensor internal hardware fault

✓
2021 BYD Dolphin, 25,000 km. SRS warning light stays on. Retrieved DTC B167200 (current). Checked sensor connector — no issues. Supply voltage 5.03V normal, CAN bus voltage normal. Swapped sensor with left-side unit for testing; DTC remained on right side (did not move to left), ruling out wiring harness fault. Measured sensor body resistance: normal approx. 5–7 kΩ, but reading was open circuit (infinite). Disassembled sensor and found internal PCB corrosion from condensation caused accelerometer chip to desolder. Cause: faulty B-pillar seal allowing rainwater ingress. Replaced right side impact sensor assembly, repaired B-pillar seal, performed sensor calibration.
Other Atto 8 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. Sources: [1]