AU
B16EF

DTC B16EF indicates the SRS (Supplemental Restraint System) control module detects a communication interruption or missing physical connection with the Right Rear Impact Sensor — Seal 6 EV

Safety System

DTC B16EF indicates the SRS (Supplemental Restraint System) control module detects a communication interruption or missing physical connection with the Right Rear Impact Sensor.

This sensor typically mounts in the right C-pillar, rear door frame, or inside the right rear quarter panel to monitor collision acceleration changes on the right rear side of the vehicle.

During a side-rear collision, the sensor transmits the acceleration signal to the SRS module to determine whether to deploy the right curtain and side airbags.

A "not connected" fault means the SRS module cannot detect the sensor during initialization or periodic communication checks.

Causes include an open circuit, disconnected connector, internal sensor open circuit, or abnormal module power supply.

This fault disables the right rear collision protection function.

As a safety-critical fault, it requires immediate repair.

The B16EF fault code on the Seal 6 EV indicates the SRS control module cannot detect the right rear impact sensor, which helps trigger side and curtain airbags in a rear-side collision. Severity is medium because this protection may be disabled. Common causes include a loose sensor connector, poor terminal contact, or damaged wiring in the right rear sill or C-pillar area. Visit an authorised dealer for diagnosis and repair. Typical repair cost data is available.
3
Cases Logged
5
Causes
Likely Causes — Seal 6 EV
  • 1Sensor wiring harness connector loose, terminal backed out, or poor contact: commonly caused by an improperly seated connector after accident repairs, or prolonged vibration loosening the retaining clip.
  • 2Wiring harness open or short circuit: The wiring harness in the right rear sill and C-pillar area breaks after vehicle wading, accidents, or long-term bending. Rodent damage or metal edge chafing causes a short to ground or power.
  • 3Internal sensor fault: Damage to the internal piezoelectric element or processing circuit causes no signal output or a power supply short circuit.
  • 4SRS control module power supply or communication fault: an abnormal module IGN power supply or ground circuit, or a CAN bus communication circuit fault prevents the module from recognizing sensors.
  • 5Sensor installation/configuration error: Configuration code (VIN matching or sensor position learning) not written after sensor replacement, or incorrect sensor part number installed.
What To Do
  • 1
    Safety preparation and fault confirmation: Disconnect the battery negative terminal and wait at least 90 seconds to fully discharge the SRS capacitor. Use VDS2000 or a BYD dedicated diagnostic tool to read fault codes and confirm B16EF is a current fault (ACTIVE), not a history fault. Verify the 'right rear impact sensor status' in the data stream shows 'not connected' or 'communication failure'.
  • 2
    Physical connection check: Remove the right C-pillar interior trim panel or rear door sill trim panel and locate the right rear impact sensor (usually a yellow connector). Inspect the connector for full insertion, broken locking tabs, and backed-out or corroded terminals. Inspect the sensor mounting bracket for deformation or looseness.
  • 3
    Circuit continuity and voltage measurement: Disconnect the sensor connector and the SRS module connector. Measure the end-to-end continuity of the wiring harness (should be less than 1 Ω). Measure the voltage from the power wire to ground (should be the 12 V battery voltage). Measure the resistance from the ground wire to ground (should be less than 1 Ω). Check the signal wire for a short to power or ground.
  • 4
    Sensor body inspection: If the wiring harness is normal, measure the sensor body resistance (refer to the workshop manual; typically several kilo-ohms to tens of kilo-ohms, depending on the model). If the resistance is infinite or zero, replace the sensor. Inspect the sensor exterior for physical cracks or signs of water ingress.
  • 5
    Replacement and Restoration: After installing a new sensor or repairing the wiring harness, listen for a 'click' to confirm the connector latch locks. Reconnect the battery, use the diagnostic tool to clear the fault code, and perform an 'SRS system self-check' or 'crash sensor configuration' (some models require writing a configuration code or performing sensor position learning).
  • 6
    Verification test: Start the vehicle and confirm the SRS warning light turns off; read the data stream and confirm the sensor status displays as 'Normal'; perform a tap test (lightly tap the sensor mounting area and observe the data stream for acceleration value changes) to confirm system function is restored.
Real-World Cases
BYD DTC AI Analysis

BYD Tang DM: Backed-out pin in right rear collision sensor connector causing intermittent fault

✓
The SRS warning light occasionally came on while driving and turned off after restarting. A VDS scan showed intermittent DTC B16EF. Inspected and found the sensor connector inside the right C-pillar trim was plugged in, but the terminals had backed out due to a previous improper repair, causing poor contact when driving over bumps. Re-crimped the terminals, applied conductive paste, and locked the connector fully. The fault has not reappeared.
Original source ↗
BYD DTC AI Analysis

BYD Song MAX: Open circuit in right rear impact sensor wiring harness after accident repair

✓
The vehicle had a right rear side scrape. After repairs at a workshop, the SRS warning light stayed on. Diagnosis showed current fault B16EF. Inspection revealed the accident had crushed and severed the wiring harness inside the right rear sill, breaking both power and signal wires. Repaired the harness by soldering and sealing with heat shrink tubing, rerouted the wiring to prevent chafing against metal edges, and cleared the fault codes. System returned to normal.
Original source ↗
BYD DTC AI Analysis

BYD Yuan EV right rear impact sensor internal short circuit after wading

✓
After water fording, the SRS warning light came on with DTC B16EF. Inspection revealed poor sealing of the right rear fender liner, letting water seep into the sensor mounting hole and causing a short circuit that damaged the sensor internally. Replaced the right rear impact sensor, cleaned corrosion and water ingress on the harness connector, and renewed the waterproof seal using a rubber gasket. Fault resolved.
Original source ↗
Other Seal 6 EV 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.B1737DTC B1737 indicates the Supplemental Restraint System (SRS) detected abnormal continuity between the right middle-row side airbag squib circuit (typically the second-row right seat side airbag or right curtain airbag) and the vehicle power supply (B+, battery positive). The SRS ECU monitors the airbag inflator resistance via an internal current source (normal resistance: 2.0–3.0 Ω). If the ECU detects the voltage across the inflator circuit remaining close to battery voltage (>5 V and approaching 12 V) instead of the expected low potential or floating state, it identifies a short to power. This fault prevents the airbag from deploying normally during a collision because the short circuit bypasses the firing current. In extreme cases, abnormal current can cause unintended deployment, posing a severe safety hazard.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 Seal 6 EV →Seal 6 EV 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.