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B16F700

For BYD Qin PRO (2018–2019) models, DTC B16F700 indicates a "Sensor line 1 configuration error" in the SRS (Supplemental Restraint System/airbag system) — Qin Plus

Safety System

For BYD Qin PRO (2018–2019) models, DTC B16F700 indicates a "Sensor line 1 configuration error" in the SRS (Supplemental Restraint System/airbag system). "Line 1" typically refers to the main power wire, signal wire, or CAN communication line of a crash sensor (e.g., front or side impact sensor).

This fault indicates the ACU (Airbag Control Unit) detects the sensor circuit's electrical configuration does not match the calibration parameters.

Possible causes include incorrect pin assignments, incorrect wiring harness connection order, or incorrect coding and matching after sensor replacement.

This safety-critical fault disables the related airbag circuit, preventing deployment during a collision.

The B16F700 fault code on the Qin Plus indicates a sensor line 1 configuration error in the SRS airbag system. Severity is medium, but it is safety-critical because the affected airbag circuit may be disabled. Common causes include missing sensor coding after replacement or incorrect wiring pin positions in the crash sensor connector. Visit an authorised BYD dealer to check wiring and perform configuration with diagnostic tools. Typical repair cost data is available.
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Cases Logged
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Causes
Likely Causes — Qin Plus
  • 1Failure to perform the 'Sensor Configuration' or 'Coding' procedure with the VDS diagnostic tool after replacing the crash sensor or airbag control module, resulting in mismatched configuration parameters.
  • 2Incorrect insertion of sensor wiring harness connector pins during repair (e.g., reversing CAN High and CAN Low wires, or installing power and signal terminals in the wrong positions), causing an incorrect circuit logic configuration.
  • 3Incorrect sensor part number installed (e.g., high-spec model sensor installed on a low-spec model); hardware pin assignment does not match the vehicle wiring harness.
  • 4Low battery voltage, electromagnetic interference, or module failure typically corrupts or erases the configuration data stored internally in the SRS control module (ACU).
  • 5Swapping the left and right side sensor connectors after vehicle accident repairs (for example, reversing the left front and right front sensor connectors) causes the system to detect a configuration logic error.
What To Do
  • 1
    Connect the VDS2000/VDS1000 diagnostic tool and enter the SRS (airbag) system. Read and record the complete fault codes. Confirm B16F700 is a current fault, not a history fault, and check for other related sensor fault codes.
  • 2
    Refer to the repair manual to locate the specific sensor corresponding to 'Line 1' (typically the left front crash sensor or driver side impact sensor). Verify the wiring harness connector color and pin positions match the standard configuration. Confirm there are no backed-out or misaligned pins.
  • 3
    Disconnect the battery negative terminal and wait 3 minutes for the SRS system to discharge. Measure the resistance to ground and continuity of each pin at the sensor wiring harness connector. Verify there are no short circuits, open circuits, or crossed wires.
  • 4
    Check the sensor part number against the vehicle BOM to confirm the sensor hardware configuration is correct. If you just replaced the sensor, execute the 'Sensor Replacement Coding' or 'Configuration Write' function to write the correct sensor parameters into the ACU.
  • 5
    If configuration writing fails, check the ACU software version and upgrade the ACU program if necessary. Inspect the wiring harness shield ground to eliminate configuration recognition errors caused by electromagnetic interference.
  • 6
    After configuration, reconnect the battery, clear the fault code, and perform an SRS system self-check (turn the ignition switch ON and observe if the instrument cluster airbag warning light turns off after the self-check). Perform a road test or simulation test to confirm fault resolution.
Real-World Cases
BYD DTC AI Analysis

Incorrect left front crash sensor configuration causing airbag light on Qin Pro DM

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Symptoms: The airbag warning light on the instrument cluster of a 2018 Qin PRO DM stays on constantly. VDS read DTC B16F700 (Sensor Line 1 Configuration Error). Diagnosis: Inspection of the left front impact sensor connector revealed a non-genuine sensor had been installed during a previous accident repair. The pin configuration did not match the original vehicle wiring harness — the high and low CAN pins were reversed. Repair: Replaced the left front impact sensor with a genuine unit, performed the 'Sensor Configuration' routine using VDS, and cleared the fault codes. The airbag light turned off and the system self-test passed.
BYD DTC AI Analysis

Qin Pro petrol version SRS module data loss causing configuration error

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Symptoms: 2019 Qin PRO petrol vehicle started after sitting for one week; instrument cluster displayed ‘Check Airbag System’ and logged DTC B16F700. Diagnosis: Inspected sensor wiring — no physical damage. Voltage measured normal. Determined the ACU lost internal configuration data. Repair: Disconnected the battery for 30 minutes to reset the ACU. After reconnecting power, used VDS to perform ‘System Configuration Restore’. Cleared the fault code; it has not returned.
BYD DTC AI Analysis

Qin Pro DM: Replacing the airbag control module without configuring it causes a fault.

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Symptoms: After a water ingress incident, the Airbag Control Unit (ACU) was replaced. After fitting the new module, the VDS reported fault code B16F700 and multiple sensor configuration errors. Diagnosis: The replacement ACU was a blank module that had not been programmed with vehicle-specific configuration parameters. Resolution: Accessed 'Special Functions' > 'ACU Configuration' through the VDS, entered the VIN and configuration codes, and configured each sensor parameter individually (including the first-line configuration). The faults cleared upon completion.
BYD DTC AI Analysis

Song/Tang models B16F700 Left Front Headlight Fault Case (Note: Definition varies by model)

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Symptoms: BYD Song/Tang instrument cluster displays 'Check Body Control System', left headlight inoperative or flickering. VDS reads BCM DTC B16F700 (Left Front Combination Lamp Fault). Diagnosis: Inspected the left headlight wiring harness connector and found water ingress and corrosion; the pin configuration did not match the BCM output. Repair: Cleaned the connector, applied conductive grease, and replaced the damaged wiring harness. Some cases required replacement of the headlight assembly or BCM. Note: This case shows that on some non-Qin Pro models, B16F700 is defined as a body control system fault, unlike the Qin Pro where it is part of the SRS definition.
Original source ↗
BYD DTC AI Analysis

Qin series body control system fault case (model definition differences)

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Symptoms: The instrument cluster on Qin Pro and Qin PLUS models displays the message "Check Body Control System" along with a left headlight malfunction. VDS reads that the BCM stores DTC B16F700. Diagnosis: Inspection of the connection between the front compartment wiring harness and headlight revealed harness damage from aftermarket modifications or backed-out pins in the headlight connector. Repair: Repaired or replaced the damaged wiring harness and recalibrated the lighting system. Note: The same fault code may point to different systems across different model years.
Original source ↗
Other Qin Plus 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.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.B110BDTC B110B indicates a fault in the internal air pump (sampling pump) of the PM2.5 air quality detector. This pump draws cabin or outside air into the PM2.5 sensor detection chamber, enabling the laser scattering sensor to measure real-time particulate matter concentration. The air conditioning controller (or BCM) sets this DTC upon detecting an open or short circuit in the pump drive circuit, or abnormal current caused by a seized pump motor. This fault disables the "Green Clean" system, causes the instrument cluster air quality display to read abnormally or disappear, and disables the automatic fresh air/recirculation switching function. It does not affect the vehicle powertrain or core thermal management functions.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.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 Qin Plus →Qin Plus 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.