AU
B16E200

DTC B16E200 indicates the SRS (Supplemental Restraint System) control module detects a configuration data mismatch for the Left Rear Impact Sensor — Seal U

Safety System

DTC B16E200 indicates the SRS (Supplemental Restraint System) control module detects a configuration data mismatch for the Left Rear Impact Sensor.

Specifically, the sensor calibration parameters, hardware serial number, or installation position coding stored in the control module do not match the physical characteristics of the connected Left Rear Impact Sensor.

This is a software/configuration fault, not a hardware open or short circuit.

This fault causes the SRS to enter a degraded mode.

The left rear impact detection function may fail or operate with abnormal trigger thresholds, affecting the deployment logic of the side curtain airbags and seat belt pretensioners.

However, it typically does not disable the entire airbag system.

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Cases Logged
5
Causes
Likely Causes — Seal U
  • 1Failure to perform 'Sensor Online Configuration' or 'Coding' using the VDS diagnostic tool after replacing the left rear crash sensor causes the new sensor hardware ID to mismatch the record stored in the control module.
  • 2Outdated SRS control module software or a corrupted configuration data area (e.g., EEPROM data loss caused by disconnecting power during vehicle repairs or a discharged battery) prevents the module from correctly identifying original sensor parameters.
  • 3Mistakenly installing the right rear crash sensor on the left side during repair, or using a non-genuine part (aftermarket parts lack original configuration coding), resulting in a position identification conflict.
  • 4After a vehicle collision, the SRS control module latches abnormal sensor status data from the impact. The historical configuration cache remains uncleared after installing a new sensor.
  • 5BYD VDS system interruption during software upgrade or module programming, resulting in a left rear sensor configuration byte write failure or checksum error.
What To Do
  • 1
    Connect the BYD VDS3000 diagnostic tool, enter the SRS system, and read the complete fault codes and freeze frame data. Record the part number and hardware version of the current left rear crash sensor. Check for other related fault codes (such as B16E100 communication fault or B16E300 hardware fault).
  • 2
    Visually inspect the left rear crash sensor mounting position (typically inside the C-pillar trim panel or on the rear bumper left bracket). Confirm the sensor has the correct orientation, the connector shows no oxidation or corrosion, and the wiring harness shows no pinching or damage. Verify the left/right marking (L/R mark) on the sensor housing matches the installation position.
  • 3
    In the VDS diagnostic tool, select 'Special Functions' → 'Crash Sensor Configuration' or 'ECU Configuration' and perform the online matching procedure for the left rear crash sensor: enter the new sensor barcode or read the sensor ID automatically, then write it to the SRS control module configuration memory area. After completing the configuration, confirm the system displays 'Configuration Successful'.
  • 4
    If configuration fails or indicates hardware incompatibility, check the SRS control module software version. If necessary, upgrade the control module software (flash the latest version of the SRS control program). After completing the upgrade, retry the sensor configuration.
  • 5
    After completing the configuration, clear the fault code and read the sensor data stream. Verify the real-time acceleration value, status bit, and configuration status of the left rear crash sensor are normal. Perform a simulated crash test (using the diagnostic tool's 'Sensor Test' function) to verify the signal response. Finally, perform a road test to verify the fault light remains off.
Real-World Cases
BYD DTC AI Analysis

Sensors not configured after rear bumper replacement caused fault.

✓
After a rear-end collision, a 2019 BYD Qin Pro DM received a new rear bumper assembly including the left rear collision sensor. The technician did not configure the sensor after installation. The SRS warning light on the instrument panel stayed on the next day, with DTC B16E200 stored. Diagnosis found the new sensor part number matched the original, but the VDS showed the sensor as "not configured." The technician performed the "collision sensor online configuration" routine and entered the new sensor serial number. The fault cleared and the data stream showed the left rear sensor status returned to normal.
BYD DTC AI Analysis

Flat battery caused configuration data loss

✓
A 2020 BYD E3 suffered severe battery drain after long-term parking. Jump-starting brought on the SRS light. Fault code B16E200 stored, along with communication fault history in multiple control modules. Inspected the left rear impact sensor connector – normal. Attempted to reconfigure the sensor using VDS, but the system displayed 'Configuration data validation failed'. Determined the SRS control module had internal EEPROM data corruption. Performed a software upgrade on the control module to refresh its firmware. After that, successfully reconfigured the left rear sensor parameters, resolving the fault.
BYD DTC AI Analysis

Swapped left and right sensor mounting positions

✓
A 2019 BYD E2 underwent C-pillar sheet metal repair. When reinstalling the impact sensors afterwards, the technician swapped the left and right positions (left rear sensor fitted to the right side, right rear sensor fitted to the left side). After starting the vehicle, it simultaneously set DTCs B16E200 (Left Rear Configuration Error) and B16F200 (Right Rear Configuration Error). VDS live data showed the left and right sensor IDs were opposite their actual installation positions. The technician removed the C-pillar trim panels, swapped the sensors back to their correct locations, cleared the fault codes, and the system returned to normal. This confirmed the configuration errors were caused by a mismatch between sensor physical positions and software configuration.
BYD DTC AI Analysis

Used second-hand parts without reconfiguration

✓
A used left rear impact sensor from a crashed car was installed on a 2018 BYD Qin Pro petrol vehicle during repairs. After installation, the dashboard displayed an SRS fault. The technician retrieved DTC B16E200. The sensor looked undamaged, but VDS showed 'Hardware ID Mismatch'. The used sensor had retained the donor vehicle's configuration data, making it incompatible with the host vehicle's SRS control module. Installing a brand new genuine sensor and performing online configuration resolved the fault. Used impact sensors are not plug-and-play; they require configuration matching.
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.