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B165E11

DTC B165E11 indicates the SRS (Supplemental Restraint System) control unit detects an abnormally low-resistance path (typically <1Ω) between the right front impact sensor signal or power circuit and body ground, constituting a short to ground — Atto 3

Safety System

DTC B165E11 indicates the SRS (Supplemental Restraint System) control unit detects an abnormally low-resistance path (typically <1Ω) between the right front impact sensor signal or power circuit and body ground, constituting a short to ground.

In BYD E2/E3/Qin EV architectures, this sensor utilizes a bipolar MEMS accelerometer and communicates with the SRS ECU via a hardwire or LIN bus connection.

A short to ground causes the ECU to continuously receive a 0V reference signal, preventing it from distinguishing between "no collision" and "circuit fault" states.

Per ISO 26262 functional safety requirements, the system enters Fail-Safe mode: it immediately illuminates the airbag fault warning lamp and disables right front airbag and side curtain airbag deployment to prevent unintended triggering or failure to deploy.

This represents a severe ASIL-D fault.

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Cases Logged
Real-World Cases
BYD DTC AI Analysis

E2 SRS light on after water ingress: right front impact sensor connector shorted due to water entry

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2019 BYD E2. The owner reported the airbag warning light stayed on after driving in heavy rain. Retrieved DTC B165E11. Inspection found visible water droplets inside the right front bumper sensor connector; the pins were green with oxidation. Cause: the connector seal ring had aged, letting water in when wading and shorting the power pin to ground. Repair: cleaned the connector pins, applied electronic contact cleaner, and replaced the waterproof seal ring. Fault resolved.
BYD DTC AI Analysis

Intermittent B165E11 on Qin EV after accident repair: bumper clip pinched wiring harness

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2020 BYD Qin EV. After right-front collision repair, the SRS warning light illuminated intermittently while driving. The scan tool showed stored fault code B165E11. Inspection found that fender liner clips re-secured during the repair pressed directly on the wiring harness. When driving over bumps, the harness insulation chafed through, allowing copper wires to contact the body. Repair: Rerouted the harness, secured it with dedicated clips, and repaired the damaged insulation with double-layer heat shrink tubing. Fault cleared.
BYD DTC AI Analysis

E3 radar modification caused SRS system false alarm: wire splicing caused short circuit

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2020 E3. Owner had front parking sensors fitted at a non-authorised workshop; the next day, the airbag warning light came on immediately at startup with fault code B165E11. Inspection found the installer had cut into the SRS wiring harness (yellow corrugated tubing) at the right front side member to tap power, damaging the signal wire insulation and creating a short to earth. Repair: removed the illegal wiring taps, repaired the SRS harness (required replacing the complete section to ensure impedance matching), and returned the vehicle to factory condition. Fault cleared.
BYD DTC AI Analysis

Sensor-internal ASIC breakdown: hard short caused by aging

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2019 Qin EV, 80,000 km, no accident or water immersion history. DTC B165E11 appeared suddenly. Measured resistance between sensor power pin and ground: only 0.3 Ω. This confirmed the internal voltage regulator had shorted. Cause: long-term operation in the engine bay’s high temperatures aged the internal capacitor, causing a power-to-ground short. Fix: replaced the right front impact sensor (part number SC-3636100), performed sensor calibration, and the system returned to normal.
Other Atto 3 Fault Codes
P0A0DBattery Energy Control Module Requested MIL IlluminationP0AA6Hybrid Battery Voltage System Isolation FaultP1A00Drive Motor "A" Performance — BYD proprietaryB1108For 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.
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.