AU
B16EF00

DTC B16EF00 indicates the airbag control unit (SRS ECU) detected a communication interruption or open circuit in the Right Rear Impact Sensor — Atto 8

Safety System

DTC B16EF00 indicates the airbag control unit (SRS ECU) detected a communication interruption or open circuit in the Right Rear Impact Sensor.

This sensor, typically installed inside the right rear door, C-pillar, or inner rear fender, monitors collision acceleration in the vehicle's right rear area.

The ECU determines a "not connected" state if it fails to receive a valid sensor signal (voltage signal or LIN bus data frame) within the specified period (typically 500ms), or if it detects circuit resistance outside the threshold (typically >10kΩ or <1Ω, depending on specific circuit design).

This safety-related fault can prevent the side airbag and side curtain airbag from deploying during a right rear collision.

The vehicle remains drivable, but the airbag system enters a degraded mode.

The B16EF00 fault code on the Atto 8 indicates a medium-severity communication interruption or open circuit in the right rear impact sensor for the airbag system. The car is usually drivable, but side or curtain airbag protection may be reduced in a right rear collision. Common causes include a loose or corroded sensor connector, or damaged wiring in the rear sill or door area. Visit an authorised dealer for diagnosis and repair. Typical repair cost data is available.
5
Cases Logged
5
Causes
Likely Causes — Atto 8
  • 1Loose sensor harness connector or poor contact: The right rear impact sensor mounts near the door or C-pillar. Frequent door operation or wading can loosen the 2-pin or 3-pin connector or oxidize the terminals, interrupting the signal.
  • 2Wiring harness open circuit or chafing: Long-term bending of the right rear sill wiring harness at the seat slide rail, carpet retaining strip, or door hinge breaks the internal copper strands while leaving the insulation intact (hidden open circuit), or wire routing during rear bumper modification accidentally damages the sensor wiring harness.
  • 3Internal sensor fault: damaged MEMS accelerometer chip, internal step-down circuit failure preventing operation, or sensor housing seal failure causing water ingress and circuit board corrosion.
  • 4Poor contact at the SRS control unit connector: Oxidized or backed-out pins at the ECU connector located under the center console or in the front compartment cause abnormal communication on a specific channel (right rear sensor channel).
  • 5Residual issues from modifications or accident repairs: Accidentally disconnecting and failing to reconnect the sensor connector when routing wiring for an aftermarket reversing camera or dashcam, or failing to re-secure the sensor bracket after sheet metal repairs, causing strain on the wiring harness.
What To Do
  • 1
    Safety preparation: Disconnect the 12V battery negative terminal. Wait at least 3 minutes to fully discharge the SRS capacitor and prevent accidental airbag deployment. Read and record the DTC freeze frame data. Confirm the vehicle speed, timestamp, and other information at the time of the fault.
  • 2
    Locate the sensor: Refer to the vehicle repair manual (usually inside the right rear C-pillar trim panel for Qin/Qin Pro; inside the right rear fender for E2/E3). Remove the interior trim panel or rear bumper. Visually inspect the right rear impact sensor (small black square with a 2-3 wire harness) and its white/yellow connector for looseness or water ingress.
  • 3
    Basic circuit inspection: Do not unplug the connector. Use a multimeter to measure the voltage on the sensor harness side (normal: 2.5-3.3V reference voltage or 5V supply, depending on sensor type). A reading of 0V or 12V indicates a circuit short to ground/short to power or an ECU fault.
  • 4
    Continuity test: Disconnect the SRS ECU connector and sensor connector. Measure the wiring harness continuity resistance between both ends (should be <1Ω) and insulation resistance (should be >10MΩ). Inspect the sill wiring harness for crush marks or breaks at the pass-through hole below the B-pillar.
  • 5
    Sensor replacement verification: If wiring is normal, replace the crash sensor with the same model (verify the part number, such as the 102... or 6A... series). Connect the sensor temporarily, power on, and clear the fault code. Perform a sensor self-check (wait 10 seconds and observe if the fault code returns).
  • 6
    System reset and road test: After resolving the fault, reinstall all interior trim panels and connect the battery. Use the VDS2000/BYD diagnostic tool to perform "SRS system configuration" and "crash sensor zero-point calibration" (required on some models). Clear the fault codes and perform a 5-10 km road test. Read the live data stream with the diagnostic tool to confirm the right rear sensor acceleration value (G value) shows normal slight fluctuations (0.00-0.05G) over road bumps, and verify no communication interruptions are recorded.
Real-World Cases
BYD DTC AI Analysis

Qin Pro DM airbag warning light on after water entered right rear door

✓
2019 Qin Pro DM. After heavy rain, the airbag warning light remained on. Retrieved fault code B16EF00. Removed the right rear C-pillar trim panel and found water inside the impact sensor connector; terminals had oxidized and turned green. Cleaned the connector with electrical contact cleaner, applied conductive grease, dried the wiring harness with compressed air, and reconnected. Fault cleared. Check the door seal drainage holes for blockages to prevent water ingress.
BYD DTC AI Analysis

E2 ride-hailing car: Aftermarket reverse camera installation accidentally cut the wiring harness.

✓
2020 BYD E2 ride-hailing vehicle. After having a reversing camera installed at an auto parts market, the instrument cluster displayed an airbag warning. The diagnostic tool logged DTC B16EF00. Inspection found the installer had disconnected the crash sensor connector when removing the right rear quarter panel trim and did not push it back in fully. The wiring harness was pinched beneath a trim clip and nearly severed. Repaired the harness, properly reconnected the connector, and secured the loom with cable ties away from the clip. Fault cleared.
BYD DTC AI Analysis

Qin EV sensors not initialized after accident repair

✓
2019 BYD Qin EV. Minor collision on the right rear. A repair shop replaced the rear bumper and right rear quarter panel. After the repair, the airbag warning light illuminated with DTC B16EF00. Inspection revealed a new impact sensor had been installed, but the zero-point calibration was not performed. Using the BYD VDS diagnostic tool, the technician performed the "Right Rear Impact Sensor Zero-Point Calibration" procedure, cleared the fault codes, and the system returned to normal.
BYD DTC AI Analysis

BYD Qin Pro (petrol) - hidden open circuit in door sill wiring harness

✓
2018 BYD Qin Pro petrol variant. The airbag warning light illuminated intermittently on rough roads; the scan tool showed intermittent B16EF00. Static circuit measurements were normal, but the fault reappeared when shaking the harness. Removed the right front seat and sill trim and found the harness had chafed against the seat rail mounting bracket—internal copper conductors were 80% broken, with only minimal contact remaining. Cut out the damaged harness section, soldered the joint and insulated it with heat-shrink tubing, then re-routed the wiring clear of moving parts. Fault eliminated.
BYD DTC AI Analysis

E3 sensor internal circuit damaged

✓
2020 BYD E3, no accidents or modifications. Suddenly logged DTC B16EF00. Sensor supply voltage measured 2.8V – normal. Ground connection normal, but no signal waveform on the LIN line. Replaced the sensor, but the fault remained. Further inspection found the original sensor had an internal short that damaged the channel driver chip inside the SRS ECU. Replaced the SRS control unit (requires replacing or rewriting the airbag configuration code) and the collision sensor. Fault resolved.
Other Atto 8 Fault Codes
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.B110A02DTC B110A02 indicates the thermal management master control unit (HVAC ECU) or body control module (BCM) failed to receive valid CAN data frames from the PM2.5 air quality sensor over consecutive communication cycles (typically 500ms per cycle). The sensor typically mounts at the HVAC unit air inlet or behind the glove box and transmits real-time particulate concentration data (unit: μg/m³) to the HVAC controller via the CAN bus. The fault is essentially a communication link layer timeout. Potential causes include physical layer wiring faults, sensor power supply failures, sensor internal MCU lockup, or CAN network topology damage. Although this non-critical fault does not directly affect driving safety, it disables the intelligent air purification strategy and the automatic fresh air/recirculation switching function. In extreme cases, it triggers a thermal management system degraded mode, limiting compressor power or fixing the air flap position.B110B07This fault code indicates abnormal operation of the internal air pump (sampling pump) in the PM2.5 air quality detection module. The PM2.5 detector uses the laser scattering principle to measure particulate concentration and requires a built-in air pump to draw ambient air into the detection chamber at a constant flow rate. The ECU sets this code when it detects an open or short in the air pump drive circuit, abnormal current (stall or free-running), or abnormal speed feedback. This fault causes the automatic air conditioning system to lose air quality sensing capability, preventing automatic switching between fresh air and recirculation modes. The instrument cluster air quality display may show '--' or a fixed value, but the fault does not affect the vehicle powertrain or basic air conditioning cooling and heating functions.B173CDTC B173C indicates the Supplemental Restraint System (SRS) detects the Right Second Row Side Airbag squib circuit resistance exceeds the calibrated threshold (typically >4.5Ω). This fault is an active diagnostic result of the SRS system, indicating a high-resistance condition in the circuit between the Airbag Control Unit (ACU) and the airbag module. Causes for excessive resistance include increased contact resistance, a partially broken wiring harness, terminal oxidation, or an aging squib wire inside the airbag module. This fault causes the system to mark the airbag circuit as 'unreliable', meaning the airbag may fail to deploy during a collision. The fault typically illuminates the instrument cluster airbag warning light (SRS light) continuously, and some models also sound a warning buzzer.
Common problems reported for Atto 8 →Atto 8 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.