AU
B16F200

DTC B16F200 indicates the airbag control unit (SRS ECU) detects abnormal configuration parameters for the right rear side impact sensor (C-pillar/rear quarter panel) — Atto 3

Safety System

DTC B16F200 indicates the airbag control unit (SRS ECU) detects abnormal configuration parameters for the right rear side impact sensor (C-pillar/rear quarter panel).

This is a configuration fault, not a hardware failure.

The sensor ID, installation position parameters, sensitivity calibration data, or hardware identification code stored in the SRS ECU do not match the installed physical sensor.

While the sensor still communicates, the ECU cannot correctly interpret its crash signal threshold, potentially causing unintended deployment or failure of the side airbags or curtain airbags.

Common triggers include: failing to perform online configuration after replacing the sensor during collision repair, using non-OEM parts causing a hardware ID mismatch, losing configuration data after an SRS software update, or interrupting the programming process resulting in incomplete configuration.

The B16F200 fault code on the Atto 3 indicates the airbag control unit has detected incorrect configuration data for the right rear side impact sensor. Severity is medium because airbag or curtain airbag operation may be affected in a crash. Common causes include missed sensor coding after replacement or installing the wrong sensor part number. Visit an authorised dealer to check parts and perform SRS sensor configuration. Typical repair cost data is available.
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Cases Logged
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Causes
Likely Causes — Atto 3
  • 1Configuration/calibration not performed after right rear crash sensor replacement: Technician replaced the hardware but did not use the VDS diagnostic tool to perform the 'crash sensor configuration' or 'coding' procedure, preventing the ECU from recognizing the new sensor's hardware ID.
  • 2Sensor hardware model mismatch: Installing a sensor with the wrong part number (e.g., fitting a low-spec sensor to a high-spec vehicle, or swapping left and right sensors) causes the SRS ECU hardware coding verification to fail.
  • 3SRS control unit software fault: Corrupted configuration data stored in the control unit internal EEPROM, outdated software version incompatible with the new sensor, or power loss during an upgrade causing configuration area data errors.
  • 4Poor wiring harness contact causes configuration communication failure: The right rear sensor mounts behind the C-pillar trim panel. A loose harness connector, backed-out pin, or oxidation prevents fully writing the configuration command to the sensor memory.
  • 5Incomplete safety system reset after an accident: Replacing the sensor after a side impact without performing 'crash data clearing' and 'system reconfiguration' on the SRS system causes the ECU to retain the old sensor's fault configuration record.
What To Do
  • 1
    Step 1: Use the BYD VDS diagnostic tool to access the SRS system. Read all fault codes, check for accompanying faults (e.g., B16F300 communication fault, U0141 lost communication with BCM), and record freeze frame data (supply voltage, temperature, mileage).
  • 2
    Step 2: Remove the right rear C-pillar trim panel. Visually inspect the right rear crash sensor for physical damage. Check the wiring harness connector (usually located above the rear sill beam or in the middle of the C-pillar) for a secure connection. Measure the connector terminal voltages (expect 12V constant power, ground, and CAN-H/CAN-L) and confirm no short or open circuits exist.
  • 3
    Step 3: Verify sensor part number: Remove the sensor and check the label part number (e.g., BYD-XXX-SRS-RR). Check the EPC system to verify the part number matches the current model year/VIN. Confirm no left/right or high/low-spec parts mix-up.
  • 4
    Step 4: Perform sensor configuration: Go to VDS → SRS system → Special Functions → 'Crash Sensor Configuration' or 'Coding'. Select 'Right Rear Sensor' and follow the prompts to enter the hardware code on the sensor label (or scan the barcode). Execute the write operation and verify the system displays 'Configuration Successful'.
  • 5
    Step 5: SRS system calibration: Run the 'Crash Sensor Calibration' function to perform zero-point calibration and sensitivity learning on the right rear sensor to ensure it correctly identifies the vehicle stationary state reference value.
  • 6
    Step 6: Clear fault codes and self-check: Clear all SRS history fault codes, run the 'System Self-Test', and confirm B16F200 does not return. Read the live data stream to confirm the right rear sensor status is 'Normal' and the signal voltage is within the specified range (typically 2.5V±0.1V static).
  • 7
    Step 7: Function verification: Perform a simulated crash test (using the dedicated diagnostic tool function or lightly tapping the vehicle body near the sensor, non-destructively). Confirm the SRS ECU correctly receives acceleration signal changes from the right rear sensor. Verify the instrument cluster airbag warning light turns off and no longer alarms.
Real-World Cases
BYD DTC AI Analysis

Sensor not configured after accident repair caused B16F200 on BYD Qin Pro DM

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Model: 2019 Qin Pro DM. Symptoms: After right-side accident repairs, the airbag warning light on the instrument cluster stayed on. VDS scan pulled code B16F200. Diagnosis: Inspection found the right rear quarter panel had been cut and replaced. The newly installed crash sensor was a genuine part, but its part number suffix did not match the vehicle configuration (a base-model sensor had been installed). Solution: Replaced the right rear crash sensor with the high-spec version (part number: BYD-3636600-C1), performed VDS online configuration and calibration. Fault resolved.
BYD DTC AI Analysis

E3 BEV SRS configuration data lost after software update

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Model: 2020 BYD E3. Symptom: After the dealership upgraded the SRS control unit software, the instrument cluster displayed an airbag fault. DTC B16F200 was stored. Diagnosis: An interruption during the upgrade corrupted the sensor configuration data in the EEPROM. Solution: Re-downloaded the correct software version, ran ‘SRS system reconfiguration’, then performed ID writing and position calibration individually for all four crash sensors (left-front, right-front, left-rear, right-rear). Cleared the fault codes, and the system returned to normal.
BYD DTC AI Analysis

Qin EV right rear sensor connector oxidised, causing intermittent configuration error

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Model: 2019 Qin EV. Symptom: Intermittent airbag warning light, frequently occurring during cold starts and clearing when warm. DTC: B16F200. Diagnosis: Measured the right rear sensor harness connector, found abnormal resistance at the CAN-L terminal (oxidation caused increased contact resistance) and incomplete configuration data. Solution: Cleaned the harness connector terminals, applied conductive grease, reconnected, and performed sensor reconfiguration. The fault has not recurred.
BYD DTC AI Analysis

Replaced rear quarter panel assembly on E2 without running the configuration procedure.

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Model: 2019 BYD E2. Symptom: After rear-end collision repairs, the owner collected the vehicle and found the airbag light on; the repair shop could not clear it. Diagnosis: When replacing the rear quarter panel assembly, the technician also replaced the built-in right rear impact sensor but did not configure it. Solution: Used VDS to access the special functions menu, selected 'Collision Sensor Replacement', completed the pairing of the new sensor with the SRS ECU as prompted, cleared the DTCs, and the system returned to normal.
Other Atto 3 Fault Codes
P0AA6Hybrid Battery Voltage System Isolation FaultB1108For 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.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.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.B173A1ADTC B173A1A indicates the right middle-row side airbag (typically located on the side of the right second-row seat or inside the C-pillar trim panel) igniter circuit resistance measures 0 Ω. In the Supplemental Restraint System (SRS), normal airbag igniter resistance ranges between 2.0 and 5.0 Ω. A resistance of 0 Ω indicates a short to ground or a short between circuit wires, preventing the Airbag Control Unit (ACU) from establishing a normal monitoring circuit. This safety-critical fault prevents the airbag from deploying during a collision, continuously illuminates the instrument panel SRS warning lamp, and may force the entire airbag system into fail-safe mode.
Common problems reported for Atto 3 →Atto 3 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.