B16E8

DTC B16E8 indicates the SRS (Supplemental Restraint System) control unit detects an abnormally low-resistance path (short to ground) between the Center Rear Impact Sensor (typically installed on the rear panel or C-pillar area) signal circuit and body ground — Atto 3

Safety System

DTC B16E8 indicates the SRS (Supplemental Restraint System) control unit detects an abnormally low-resistance path (short to ground) between the Center Rear Impact Sensor (typically installed on the rear panel or C-pillar area) signal circuit and body ground.

This sensor uses a piezoelectric or capacitive accelerometer.

During normal operation, it outputs a 0.5-4.5V analog voltage signal to the SRS control unit to reflect collision acceleration.

A short to ground causes the control unit to continuously receive a voltage signal near 0V, triggering the following: 1) The system determines the sensor has failed, enters fail-safe mode, and disables the associated airbags (including side curtain airbags and rear collision protection functions); 2) During an actual rear collision, the system cannot accurately identify collision severity, causing delayed or no airbag deployment; 3) If the short-circuit resistance is unstable, it triggers an intermittent fault, causing the SRS warning lamp to illuminate erratically.

This is a hard fault.

Upon detection, the control unit stores the DTC and illuminates the instrument cluster airbag warning lamp.

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Cases Logged
BYD DTC AI Analysis

SRS light on after driving through water: Aged boot seal caused water ingress into sensor

2019 BYD Yuan EV. The owner reported that after driving through floodwater during heavy rain, the airbag warning light stayed on. Scanned with VDS and retrieved current fault code B16E8. Inspected the rear area and found the centre rear impact sensor mounted centrally on the rear bulkhead, with obvious water stains and green copper corrosion inside its connector. Further inspection revealed that the boot seal had aged and deformed, allowing rainwater to enter the rear bulkhead cavity via the tail light housings. Rectification: replaced the centre rear impact sensor assembly, cleaned the connector terminals and applied conductive anti-corrosion paste, replaced the boot seal, and cleared the rear bulkhead drain holes. Followed up for three months after repair with no recurrence.
BYD DTC AI Analysis

False alarm after rear-end collision repair: Rear seat bolt crushed wiring harness

A 2021 BYD Tang developed an intermittent SRS warning light after repairs at an independent shop following a low-speed rear-end collision. Diagnosis found an intermittent B16E8 DTC. Removing the rear interior trim revealed that the repair shop had not secured the rear bulkhead harness in its channel according to OEM routing. Instead, the rear seat mounting bolts had pinched the harness, damaging the insulation and exposing the copper conductors to the vehicle body. The technicians rerouted the harness, repaired the damaged wires (soldered and applied double-layer heat shrink tubing), and adjusted the seat mounting bracket to prevent interference. After clearing the DTCs, they road tested the vehicle repeatedly and confirmed the fault was gone.
BYD DTC AI Analysis

New vehicle assembly defect: damaged wiring harness protective sleeve causing a short to ground

One week after delivery, the airbag warning light came on in a brand-new 2020 BYD Qin petrol model. Scanning retrieved fault code B16E8-00 (current). Inspection found the rubber grommet on the middle/rear impact sensor wiring harness was not fully seated where it passes through the C-pillar sheet metal hole, leaving the harness in direct contact with the sharp metal edge. Driving vibrations cut through the insulation, causing a short to ground. Repair action: Repair the damaged wire, replace the harness rubber grommet, fit a protective rubber ring over the sheet metal hole edge, and ensure a safe clearance between the harness and metal edge. This is an assembly process issue—vehicles from the same production batch require inspection.
BYD DTC AI Analysis

Sensor internal component aging: seal failure from high-temperature environment

A 2019 BYD Song MAX, four years old, driven in a hot climate its whole life, came in with the SRS warning light stuck on. The scan tool pulled DTC B16E8. We measured the sensor harness ground resistance: normal, open circuit. After reconnecting the sensor, the signal wire to ground showed only 12Ω—a clear internal short. Opening the sensor revealed the PCB potting compound had aged and cracked, allowing a capacitor lead to touch the metal housing. Repair: replaced the center rear impact sensor assembly (confirmed correct part number for the vehicle), cleared the fault codes, and ran a system calibration. Some variants also require a zero-point calibration with the diagnostic tool.
Data confidence: Community This information is for reference only. Always consult a qualified technician for diagnosis and repair. Do not attempt high-voltage system repairs yourself.