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B1676-00

DTC B1676-00 indicates the airbag control module (SRS ECU) detects a communication interruption or circuit fault in the Left Rear Side Impact Sensor (LR-SIS) — Atto 3

Safety System

DTC B1676-00 indicates the airbag control module (SRS ECU) detects a communication interruption or circuit fault in the Left Rear Side Impact Sensor (LR-SIS).

The sensor typically mounts on the vehicle's left rear side panel, inside the C-pillar trim panel, or on the side of the rear seat to monitor collision acceleration at the left rear of the vehicle.

The ECU sets this fault code when it detects an open circuit, a short circuit, or internal sensor resistance outside the calibrated range (typically 2.0–3.0 kΩ, depending on the vehicle model).

This SRS communication link fault may prevent the side airbags and side curtain airbags from deploying correctly during a side impact.

It can also force the entire airbag system into a degraded protection mode, severely compromising passive safety performance.

5
Cases Logged
Real-World Cases
BYD DTC AI Analysis

Left rear quarter panel wiring harness wear on a BYD Qin Pro DM causing B1676-00

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Symptoms: Airbag warning light constantly illuminated on the instrument panel. DTC B1676-00 stored (left rear side impact sensor disconnected). Diagnosis: Inspected the sensor connector at the left rear C-pillar — connection OK. Measured sensor resistance: 2.3kΩ (normal). Resistance fluctuated when wiggling the wiring harness. Peeled back the corrugated tubing and found the harness had chafed against the body metal edge, wearing through the insulation and causing an intermittent open circuit in the copper wire. Solution: Repaired the damaged harness (resoldered connections and applied heat shrink tubing), rerouted the harness away from sharp edges, and wrapped it with foam to prevent abrasion. Cleared the fault code; system returned to normal.
BYD DTC AI Analysis

BYD Song MAX aftermarket audio modification caused sensor communication fault

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Symptoms: Vehicle displayed "Check SRS System" after starting, with DTC B1676-00 present. Diagnosis: Recent audio system modification involved removal of the left rear quarter trim panel. Found the sensor connector not fully seated during the modification, with a broken locking tab causing an intermittent connection. Also found the added subwoofer harness tied too tightly to the sensor harness, causing signal interference. Resolution: Replaced the damaged sensor connector by splicing in an OEM connector. Rerouted the wiring to ensure at least 20 cm separation from the audio harness. Performed sensor configuration learning using the diagnostic tool. Fault resolved.
BYD DTC AI Analysis

BYD Tang DM sensor connector oxidised after wading

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Symptoms: After driving through heavy rain and waterlogged roads, the airbag warning light illuminated intermittently, and fault code B1676-00 appeared sporadically. Diagnosis: Found water stains and green oxidation inside the left rear side impact sensor connector, causing high contact resistance (measured 5.6kΩ, outside normal range). Traced the cause to a previous window tinting job that left the C-pillar waterproof membrane improperly sealed. Fix: Cleaned the connector terminals thoroughly with precision instrument cleaner and fine sandpaper, applied conductive grease, replaced the waterproof sealing ring, and resealed the waterproof membrane. The fault has not returned.
BYD DTC AI Analysis

BYD e5 EV sensor body damaged

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Symptoms: Instrument cluster displayed airbag system fault. Code B1676-00 was current and could not be cleared. Diagnosis: Measured voltage at the sensor connector (normal: 5V reference) — voltage normal. Disconnected sensor and measured internal resistance: infinite (open circuit). Normal resistance: 2.0–3.0 kΩ. Checked wiring harness continuity: normal, no short or open circuits. Determined sensor internal piezoelectric element had failed. Resolution: Replaced left rear side impact sensor with genuine part, performed SRS system configuration, ran system self-test — passed.
Original source ↗
BYD DTC AI Analysis

BYD Song Pro sensor not connected after accident repair

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Symptoms: The vehicle was scraped on the left rear side. After repair at a workshop, the airbag warning light stayed on with DTC B1676-00. Diagnosis: The accident repair involved body work on the left rear quarter panel. Inspection found the sensor connector left unplugged (the technician forgot to reconnect it). Fresh paint covered the ground point on the sensor mounting bracket, causing a poor ground connection. Fix: Reconnected the sensor connector and verified the lock tab was fully seated. Sanded the paint off the ground point to restore bare metal contact. Tightened the sensor mounting bolts to 8–10 N·m. Cleared the fault code and the system operated normally.
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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.