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B1719-00

DTC B1719-00 indicates the SRS (Supplemental Restraint System) control unit detects an abnormally low-resistance connection (short circuit) between the Driver Knee Airbag squib circuit and the vehicle power supply (B+) — Qin Plus

Safety System

DTC B1719-00 indicates the SRS (Supplemental Restraint System) control unit detects an abnormally low-resistance connection (short circuit) between the Driver Knee Airbag squib circuit and the vehicle power supply (B+).

Under normal operating conditions, the airbag squib circuit exhibits high resistance (2-5 Ω) and lacks continuity to power or ground.

A short to power causes the SRS ECU to detect an abnormally high circuit voltage (close to 12 V) and register a severe fault.

This condition may prevent the airbag from deploying correctly during a collision (as the short circuit bypasses the current) or, in extreme cases, cause unintended deployment (though a short circuit typically prevents rather than triggers ignition).

Repair this critical safety fault immediately.

5
Cases Logged
Real-World Cases
BYD DTC AI Analysis

Qin EV450: Aftermarket floor mats pierced the wiring harness, causing a short circuit.

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A 2018 Qin EV450 logged DTC B1719-00. Inspection found the owner had fitted full-surround floor mats. The retaining pins had pierced the knee airbag wiring harness beneath the dashboard, causing a short between the harness positive wire and the airbag circuit. The airbag warning light stayed on continuously, and the vehicle could not engage the high-voltage system (SRS faults trigger HV interlock on some models). Removed the floor mats, repaired the damaged harness by replacing a 15 cm section, and rewrapped it with waterproof insulation tape. Fault resolved.
BYD DTC AI Analysis

Water ingress and corrosion in Qin 100 connectors after wading

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2017 BYD Qin 100 developed DTC B1719-00 after wading through floodwater. Inspection revealed the driver-side knee airbag connector (above the pedal) had a deteriorated seal; water ingress caused electrolytic corrosion between the pins, creating a short to power. The airbag warning light illuminated intermittently after water exposure, sometimes clearing once dry. Cleaned the connector thoroughly with electronic cleaner, replaced the damaged pins and seal, and applied conductive grease. Fault resolved.
BYD DTC AI Analysis

Internal short circuit in airbag module igniter

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A Qin EV300 with 80,000 km logged DTC B1719-00. Wiring checks revealed no faults. After disconnecting the airbag module connector, we measured the harness side and found no short to power. However, measuring the knee airbag module itself, we found continuity between both pins and the module's metal casing, indicating the internal igniter insulation had broken down. Replaced the left knee airbag module (part number: G5A-5820500 or superseded version). Programming and matching cleared the fault. Caution: Dispose of the old airbag as hazardous waste.
BYD DTC AI Analysis

Dashboard wiring harness chafing against bracket

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2017 BYD Qin 80: Airbag warning light intermittently illuminated when driving on rough roads. Scanner showed intermittent fault code B1719-00. Inspection found untreated burrs on the dashboard frame; long-term vibration had worn through the knee airbag wiring harness insulation where it contacted the metal bracket, causing intermittent shorts to ground or power. Repair: Repaired the wiring harness, installed rubber protective sleeves and corrugated tubing at the interference points, and ground down the frame burrs. The fault has not returned.
BYD DTC AI Analysis

SRS control unit software false positive

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After routine servicing at a dealership, a Qin 100 suddenly logged DTC B1719-00. Checks of the wiring and airbag module found no issues. A review of repair history showed the vehicle had previously received an SRS software update. The cause was a software version compatibility issue triggering a false DTC. Solution: Flashed the SRS control unit to the latest software version (or rolled back to a stable version) and performed configuration coding. The fault code cleared and the airbag system resumed normal self-check operation.
Other Qin Plus 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: Community This information is for reference only. Always consult a qualified technician for diagnosis and repair. Do not attempt high-voltage system repairs yourself.