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B16F100

DTC B16F100 indicates an internal electrical fault or signal plausibility error in the right (passenger side) Side Impact Sensor (SIS) — Qin Plus

Safety System

DTC B16F100 indicates an internal electrical fault or signal plausibility error in the right (passenger side) Side Impact Sensor (SIS).

This sensor typically mounts inside the right B-pillar trim panel or right front door cavity.

It monitors the acceleration change rate (Delta-V) during a side impact and transmits an analog voltage signal (normal range 0.4-4.6V) to the SRS airbag control unit via the LIN bus or a hardwired connection.

Fault trigger conditions include internal accelerometer self-test failure, signal voltage continuously outside thresholds (too high/too low), sensor ID verification failure, or communication loss with the SRS module.

This fault prevents the right side airbags and side curtain airbags from deploying correctly during a side impact, or forces the airbag system into a degraded protection mode (retaining only the driver's front airbag function).

This is a safety-critical fault requiring immediate repair.

The B16F100 fault code on the Qin Plus indicates a medium-severity internal electrical fault or signal plausibility problem in the right side impact sensor. Common causes include a failed sensor accelerometer or signal chip, or water ingress and corrosion in the B-pillar or door wiring connector. Because this can affect side airbag deployment, the recommended fix is to visit an authorised dealer for diagnosis and sensor or wiring repair. Typical repair cost data is available.
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Cases Logged
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Causes
Likely Causes — Qin Plus
  • 1A damaged piezoelectric accelerometer element or failed signal processing chip inside the right side impact sensor causes the output signal to drift or remain at a fixed voltage.
  • 2Water ingress and oxidation at the sensor wiring harness connector (commonly due to rainwater leaking past a poorly sealed lower right B-pillar or aging window seals), causing a short to ground in the power or signal wire.
  • 3Internal copper conductors in the right front door wiring harness break at the hinge bend (metal fatigue from frequent door opening and closing), causing an intermittent open circuit in the sensor power supply or communication line.
  • 4Replacing the sensor with a new unit without performing coding configuration after right-side accident repair (some BYD models require using VDS to execute 'Crash Sensor ID Configuration' and 'Zero Point Calibration' after sensor replacement).
  • 5Internal fault in the SRS control unit sampling circuit prevents correct identification of the right sensor signal, or a deformed sensor mounting bracket causes the sensor mounting angle to deviate beyond the allowable ±5° range.
What To Do
  • 1
    Safety Preparation: Disconnect the 12V battery negative terminal and wait at least 3 minutes to allow the SRS capacitor to fully discharge. Remove the service disconnect switch (if equipped with a high-voltage system). Use the VDS2000/VDS2100 diagnostic tool to read the complete DTC snapshot. Record the vehicle speed, sensor voltage values, and freeze frame data at the time of the fault.
  • 2
    Physical inspection: Remove the right B-pillar lower trim panel (remove the door sill trim first). Check the crash sensor connector (part number usually starts with 5A or 6A) for looseness, water ingress (look for green oxidation), or terminal back-out. Inspect the sensor mounting bracket for deformation. Verify the fixing bolt torque is 7-9 N·m.
  • 3
    Circuit measurement: Keep the sensor disconnected. Measure the harness-side connector: power pin (usually IG+) to ground voltage should be 9-16V (ignition ON), ground pin resistance should be <1Ω, and signal wire (LIN or PWM) static voltage to ground should be approximately 2.5V (depending on vehicle model). Inspect the wiring harness at the right front door hinge for breaks.
  • 4
    Component swap verification: If the wiring is normal, disconnect the power and swap the right-side sensor with the left-side sensor (verify the part numbers match). Restore power, clear the fault code, and perform a road test or simulate vibration. If the fault code changes to B16E100 (left-side crash sensor fault), this confirms an internal fault in the original right-side sensor.
  • 5
    Replacement and configuration: After installing the new sensor, use a diagnostic tool on some models (such as Qin Pro) to execute the 'SRS Sensor Configuration' function, write the sensor serial number, and perform 'Longitudinal/Lateral Zero Point Calibration'. After completion, run a system self-diagnosis and confirm the B16F100 status is 'History' or 'None'.
  • 6
    Final verification: Restore all connections, reconnect the battery, and start the vehicle. Verify the airbag warning light turns off (it should turn off after the self-check). Perform a right-side crash sensor signal simulation test (some diagnostic tools support this) to confirm the SRS control unit correctly receives the sensor acceleration signal.
Real-World Cases
BYD DTC AI Analysis

Water ingress at right B-pillar caused sensor pin corrosion

✓
2019 BYD Qin Pro DM. Owner reported the airbag warning light stayed constantly illuminated after wading through water in heavy rain. The scan tool displayed active fault code B16F100. Removed the right B-pillar trim panel and found significant copper oxide corrosion inside the side impact sensor connector. Insulation resistance between pin 1 (12V supply) and pin 3 (ground) measured only 200 Ω. Cleaned the connector terminals with electrical contact cleaner and inspected the B-pillar drain hole for blockages. Cleared the drain hole; fault resolved. Recommend checking door seal integrity.
BYD DTC AI Analysis

Sensor configuration not performed after accident repair.

✓
2018 Qin Pro petrol variant. Following right-side collision repairs, replaced the right front door and B-pillar inner panel, and fitted a new impact sensor. Post-repair VDS scan showed B16F100 (current fault). Checked sensor power and ground – normal. Wiring harness continuity good. Reviewed repair records: replacement sensor part number matched the original, but the technician had not performed the configuration procedure. Used VDS to access SRS system → Special Functions → Impact Sensor Configuration. Selected 'Right Side Sensor' and followed the prompts to complete ID writing and zero-point calibration (vehicle must be on level ground with the steering wheel centred). Configuration completed, fault code cleared automatically, system returned to normal.
BYD DTC AI Analysis

Internal break in right front door wiring harness at hinge point

✓
2019 BYD Qin Pro DM. Customer reported intermittent airbag warning light, especially after opening or closing the right front door. Diagnostic scan tool retrieved stored DTC B16F100. Static measurement showed normal sensor supply voltage, but lightly shaking the right front door harness caused the signal wire (LIN bus) voltage to ground to swing between 0 V and 5 V. Stripped back the corrugated tube at the right front door hinge and found the internal copper strands of the harness fractured at the bend — only the outer insulation remained holding the ends together (metal fatigue from frequent door operation). Resoldered the broken pink signal wire, applied double-layer heat‑shrink tubing for waterproofing, and secured the harness routing to prevent repeated flexing. Fault eliminated.
BYD DTC AI Analysis

Sensor mounting bracket deformation causing abnormal signal

✓
2018 Qin Pro. The right-side B-pillar was deformed by a side impact. An independent shop performed body repair but did not replace the sensor. Several months later, DTC B16F100 appeared. Inspection found the sensor mounting bracket had stretched and deformed during the repair, shifting the sensor mounting angle approximately 15° (beyond the permitted ±5° tolerance) and causing an incorrect internal accelerometer reference position. Replaced the B-pillar inner panel (including sensor bracket) and the impact sensor, torqued to specification, and performed zero-point calibration. Fault resolved.
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.