AU
B16E0-00

DTC B16E0-00 indicates a short to ground in the Left Rear Impact Sensor signal circuit within the Supplemental Restraint System (SRS) — Seal U

Safety System

DTC B16E0-00 indicates a short to ground in the Left Rear Impact Sensor signal circuit within the Supplemental Restraint System (SRS).

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

A short to ground indicates abnormal continuity (resistance below the normal range) between the sensor power wire, signal wire, or shield and the vehicle body metal frame.

This causes the SRS control module to receive a continuous low-level signal.

This fault forces the SRS into fail-safe mode and may cause the following: 1) The left rear side airbag/curtain airbag fails to deploy during an actual collision. 2) The system misinterprets the fault as a collision and inadvertently deploys the airbag. 3) Entire SRS functionality restricts, severely compromising passive safety performance.

The B16E0-00 fault code on the Seal U indicates a short to ground in the left rear impact sensor circuit within the SRS airbag system. This is a high-severity safety fault because it may prevent correct airbag deployment or restrict SRS operation. Common causes include damaged wiring in the left rear side panel or water/corrosion in the sensor connector. Visit an authorised dealer for diagnosis and repair. Typical repair cost data is available.
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Cases Logged
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Causes
Likely Causes — Seal U
  • 1Wiring harness chafing or crushing inside the left rear side panel: Prolonged vehicle vibration causes the wiring harness to rub against a metal edge, damaging the insulation and shorting the signal wire to ground.
  • 2Sensor connector water ingress and corrosion: Car washing, wading, or poor sealing causes a short circuit between connector terminals, forming a path to ground.
  • 3Rear crash sensor internal fault: Damaged internal electronic components cause a short circuit between the power supply terminal and the ground terminal.
  • 4Improperly secured wiring harness after collision repair: Incorrect routing during left rear collision repair caused the seat bracket or interior trim panel screws to pinch the wiring harness.
  • 5SRS control module internal short circuit: A fault in the control module internal signal processing circuit causes the left rear sensor channel to short to ground.
What To Do
  • 1
    Safety preparation: Disconnect the 12V battery negative terminal, wait at least 90 seconds for the SRS system capacitor to discharge, and wear an anti-static wrist strap.
  • 2
    Visual inspection: Remove the left C-pillar trim panel and the left side of the rear bumper. Inspect the left rear crash sensor (usually numbered Y3) for physical damage. Check the connector for looseness, water ingress, or signs of corrosion.
  • 3
    Circuit continuity test: Set the multimeter to measure resistance. Disconnect the sensor connector and the SRS module connector. Measure the resistance between the harness-side signal pin (usually corresponding to the pin in the scan tool data stream) and body ground. The standard reading is infinity (OL). A reading of 0-5Ω confirms a short to ground.
  • 4
    Segmented fault isolation: Follow the left rear side panel wiring harness routing (passing under the left rear door frame weatherstrip to the floor harness). Gradually open the corrugated conduit to inspect the harness outer sheath. Focus on contact points with the seat track, seat belt retaining bolt, and rear fender liner.
  • 5
    Insulation repair or replacement: If the wiring harness is damaged, apply a double layer of heat-shrink tubing or waterproof tape. If the sensor is faulty, replace it with an OEM left rear crash sensor (part number usually starts with 5A-). Tighten to 8-10 N·m.
  • 6
    System verification: Reconnect all connectors and restore power. Use VDS or Launch X431 to clear the fault code. Perform an SRS system self-test. Read the data stream to confirm the left rear sensor voltage signal changes normally with impact within the 0.5-4.5V range. Perform a simulated collision test (lightly tap the sensor mounting position) and observe data stream changes.
Real-World Cases
BYD DTC AI Analysis

BYD Qin EV300 left rear impact sensor short circuit after wading

✓
After driving through water about 30 cm deep, the airbag warning light on the instrument panel stayed on. Read fault code B16E0-00. Removed the left rear sill trim panel and found water inside the left rear impact sensor connector. Water caused a short circuit between pin 3 (signal wire) and pin 1 (ground). Dried the connector with compressed air, applied electronic contact cleaner, and replaced the seal ring. The fault cleared. Check the left rear quarter panel vent seal strip for deterioration.
BYD DTC AI Analysis

Wiring harness crimping after accident repair caused short circuit on Qin 100

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The vehicle was rear-ended on the left side. After the left rear quarter panel was replaced at an external repair shop, DTC B16E0-00 set. Inspection revealed that when reinstalling the interior trim panel, the technician had routed the left rear impact sensor harness (yellow corrugated tubing) beneath the seat mounting bolt. The bolt washer crushed the insulation, allowing the copper wires to contact the chassis directly. Re-routed the harness, secured it with dedicated clips, and replaced the damaged wire section. Fault cleared.
BYD DTC AI Analysis

Qin EV450 sensor internal short circuit

✓
The airbag warning light illuminated intermittently during normal use, with increased frequency in humid weather. A wiring harness check found no short to earth, but measuring the left rear impact sensor alone showed a resistance of only 12 Ω (normal is several kilohms). This pointed to an internal MEMS accelerometer circuit fault causing a power short to earth. Replaced the left rear impact sensor (part number 5A-3638400), performed configuration coding and adaptation, and fully resolved the fault.
BYD DTC AI Analysis

Retrofitting a reversing camera damaged the wiring harness.

✓
The owner installed a surround-view camera system themselves. While drilling to route wiring on the left rear side, the drill bit damaged the factory left rear impact sensor harness, breaching the insulation and exposing the copper core. The exposed core contacted the body metal, triggering DTC B16E0-00. Removed the left rear quarter trim panel and found a ~3mm wound in the harness from the drill. Cut out the damaged section, spliced in a heat-resistant wire (0.5mm², 125°C rated) by soldering, and sealed with double-layer heat shrink tubing. Normal operation restored.
Other Seal U Fault Codes
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.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.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.B173712DTC B173712 indicates a short to power in the firing circuit of the right second-row side airbag module in the Supplemental Restraint System (SRS). Specifically, the "right second-row side airbag" typically refers to the side impact airbag located in the right B-pillar or the side of the right seat. The "12" suffix indicates a circuit short to battery positive (B+). This fault causes the following conditions: 1) The airbag may fail to ignite and deploy during a collision, resulting in a loss of side impact protection. 2) In extreme cases, unintended triggering may cause accidental airbag deployment. 3) The SRS control unit detects abnormally high circuit voltage (typically above 4.5V) and enters fault protection mode. This may disable the entire airbag system and continuously illuminate the instrument cluster airbag warning light.
Common problems reported for Seal U →Seal U 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.