AU
B16F0-00

B16F0-00 indicates a short to body ground in the Supplemental Restraint System (SRS) Right Rear Impact Sensor signal circuit — Seal U

Safety System

B16F0-00 indicates a short to body ground in the Supplemental Restraint System (SRS) Right Rear Impact Sensor signal circuit.

This sensor typically mounts in the C-pillar or right rear quarter panel area to monitor collision acceleration at the right rear of the vehicle.

The SRS ECU logs this fault code when it detects abnormal voltage to ground on the sensor signal wire (continuous low level or excessively low impedance).

This fault prevents the SRS ECU from accurately receiving the right rear impact signal.

It may cause the airbag system to fail to deploy correctly during a side or rear impact, or to deploy inadvertently under normal conditions.

Consequently, the system enters fail-safe mode, illuminates the airbag warning light, and may disable certain airbag functions.

3
Cases Logged
5
Causes
Likely Causes — Seal U
  • 1Damaged insulation on the right rear impact sensor wiring harness causing a short to the body (commonly due to abrasion at the C-pillar wiring hole or the edge of the rear bumper mounting bracket)
  • 2Water ingress or corrosion in the sensor connector causing a short circuit between terminals (common after driving through water, rear windshield leaks, or direct high-pressure washing of the C-pillar area)
  • 3Internal electronic component failure in the right rear impact sensor causes the signal terminal to short to ground (internal sensor short circuit).
  • 4Vehicle modifications damaged the wiring harness (e.g., mounting screws crushed the harness or drilling damaged it when installing a reversing camera, parking sensors, or dashcam rear camera).
  • 5SRS ECU internal sampling circuit fault causing false detection (rare; consider only after verifying the wiring harness and sensors are normal)
What To Do
  • 1
    Safety preparation: Disconnect the battery negative terminal and wait 3 minutes to discharge the SRS capacitor for safe operation.
  • 2
    Fault confirmation: Connect the diagnostic tool to read the DTCs. Confirm B16F0-00 is a current fault (Active) and record the freeze frame data.
  • 3
    Visual inspection: Remove the right C-pillar trim panel and rear bumper inner liner. Check the right rear impact sensor connector (located at the lower C-pillar or right rear side panel) for looseness, water ingress, or corrosion, and inspect the wiring harness for obvious damage.
  • 4
    Connector treatment: Clean the connector terminals, apply conductive grease, reconnect and ensure the lock is fully engaged. Clear the fault code and road test to verify.
  • 5
    Sensor substitution test: Disconnect the faulty sensor and install a known good sensor. Clear the fault code and observe if it returns (to distinguish between a sensor fault and a wiring harness fault).
  • 6
    Wiring harness continuity check: Disconnect the SRS ECU (K21) and sensor (K06) connectors. Measure the resistance between the harness terminals (should be <1Ω) to confirm no open circuit.
  • 7
    Insulation-to-ground check: Measure the resistance to body ground for the sensor signal wire (K21-29 to K06-1, L/Y wire) and the ground wire (K21-30 to K06-2, G/Y wire) (should be >1MΩ), and locate the short circuit.
  • 8
    Wiring harness repair: Wrap damaged areas with waterproof insulating tape, install corrugated conduit for protection, and adjust the wiring harness routing to avoid contact with sharp edges.
  • 9
    ECU inspection: If the wiring harness and sensor are normal, measure the voltage at the corresponding SRS ECU terminal. Replace the SRS ECU if necessary.
  • 10
    Final verification: Restore all connections, clear fault codes, perform a rough road test and SRS system self-check, and confirm the warning lamp turns off and no new fault codes appear.
Real-World Cases
BYD DTC AI Analysis

BYD Qin - Water ingress in right rear impact sensor connector caused short to ground

✓
The SRS warning light on a 2017 BYD Qin EV300 turned on suddenly after driving in wet weather. The scan tool retrieved DTC B16F0-00. Inspection beneath the right C-pillar revealed water inside the sensor connector, with the terminals showing oxidation and corrosion. The root cause was a deteriorated rear windscreen seal that allowed rainwater to track down the C-pillar and enter the connector, shorting the signal terminal to ground. Repair: cleaned the connector terminals, dried with compressed air, applied waterproof conductive grease, replaced the rear windscreen seal, and re-routed the wiring harness to prevent water pooling. Cleared the fault codes and road tested—fault resolved.
Original source ↗
BYD DTC AI Analysis

BYD Qin - Retrofitted reversing camera caused wiring harness chafing and a short to ground.

✓
A 2018 BYD Qin EV450 presented with the SRS warning light constantly illuminated one week after a reversing camera installation at a third-party accessory shop. Diagnostic scan revealed DTC B16F0-00. Investigation showed the installer had routed the rear camera harness through the same C-pillar grommet used by the right rear impact sensor wiring, and a fixing screw pressed directly on the sensor harness. This damaged the insulation, exposing copper conductors and causing a short to earth against the bodywork. Repaired the damaged harness by wrapping with insulation tape and fitting corrugated tubing, rerouted the camera harness to avoid interference with the factory harness, and replaced the fixing screw with a dedicated wiring clip. Cleared the fault code and confirmed the system returned to normal operation.
Original source ↗
BYD DTC AI Analysis

BYD Qin – Internal fault in right rear impact sensor causing short circuit

✓
A 2017 Qin 100 with no accident history had an SRS warning lamp that illuminated intermittently. The diagnostic scanner showed DTC B16F0-00. Initial inspection found the wiring harness visually undamaged and connectors in good condition. Swapped the right and left rear impact sensors for a substitution test. After clearing DTCs and road testing, the fault code changed to B1677-00 (left rear impact sensor short to ground), confirming the fault moved with the sensor. Disassembling the faulty sensor revealed the internal piezoelectric element seal had failed, causing a short circuit. Replaced the right rear impact sensor (part number per vehicle configuration), installed with the arrow pointing forward (crash sensing direction), and tightened to the specified torque (9-11 N·m). Replacing the sensor resolved the fault completely.
Original source ↗
Other Seal U 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.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.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.
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.