AU
B1610-00

DTC B1610-00 indicates the SRS (Supplemental Restraint System) ECU detected abnormal resistance in the front passenger-side frontal airbag ignition circuit, specifically 0 Ω (short circuit) or infinite resistance (open circuit) — Seal U

Safety System

DTC B1610-00 indicates the SRS (Supplemental Restraint System) ECU detected abnormal resistance in the front passenger-side frontal airbag ignition circuit, specifically 0 Ω (short circuit) or infinite resistance (open circuit).

In the BYD fault definition system, this code means "front passenger frontal airbag disconnected," indicating a loss of circuit integrity between the SRS ECU and the front passenger airbag module.

This hard fault triggers the system fail-safe mode: the SRS ECU disables all airbag deployment (including the driver-side, side, and curtain airbags) and continuously illuminates the instrument cluster airbag warning lamp.

Because this fault involves the occupant passive safety system, it carries the highest priority.

The airbag system returns to normal standby status only after fault repair.

3
Cases Logged
5
Causes
Likely Causes — Seal U
  • 1Front passenger airbag connector loose, terminal backed out, or corroded: The yellow connector at the rear of the airbag module or on the right side of the dashboard is not fully locked, or oxidized terminals cause excessive contact resistance or an open circuit.
  • 2Internal damage to the clock spring (spiral cable): The spiral ribbon cable routed under the steering wheel breaks or short-circuits, interrupting the front passenger airbag circuit signal (some models share or link detection with the front passenger airbag circuit).
  • 3Water ingress at the SRS ECU connector or damaged terminals: The ECU mounts beneath the center console. After driving through water, corrosion or terminal back-out at connector G10/M40 prevents airbag resistance detection.
  • 4Airbag module squib fault: Internal airbag igniter short circuit (resistance 0Ω) or open circuit (resistance ∞), usually caused by airbag impact, moisture exposure, or aging.
  • 5Dashboard wiring harness wear: Air conditioning duct or metal bracket chafes through the airbag wiring harness insulation, causing a short to ground or a completely broken wire.
What To Do
  • 1
    Use the BYD VDS or Launch X431 diagnostic tool to read fault codes, confirm B1610-00 is a current DTC, and record ambient temperature and vehicle status from the freeze frame data.
  • 2
    Perform the safe power-down procedure: turn off the ignition, disconnect the battery negative terminal, and wait at least 90 seconds to fully discharge the SRS capacitor and prevent accidental airbag deployment.
  • 3
    Visually inspect the front passenger airbag connector (yellow, usually located behind the glove box or on the back of the airbag), verify the locking tab is fully engaged, and check for backed-out pins or green corrosion.
  • 4
    Disconnect the SRS ECU connectors (G10 and M40). Use a multimeter to measure the resistance between the corresponding terminals of the front passenger airbag circuit. The normal value is 2.0 ± 0.3 Ω. A reading of 0 Ω indicates a short circuit; an infinite reading indicates an open circuit.
  • 5
    If resistance is abnormal, disconnect the airbag connector and directly measure the airbag unit resistance (normal: approximately 2.0Ω). If normal, measure harness continuity section by section, focusing on the clock spring (spiral cable) continuity.
  • 6
    Connect a 2.7Ω dedicated simulation resistor to the circuit in place of the airbag. If the fault code changes to a stored fault, the airbag unit is faulty. If it remains a current fault, check the wiring harness and ECU.
  • 7
    Repair or replace the faulty component (airbag, clock spring, wiring harness, or ECU). Reconnect all connectors and verify the yellow connector locks into place.
  • 8
    Connect the battery, turn the ignition switch to the ON position, use the diagnostic tool to clear the fault codes, perform the 'SRS system self-diagnosis', and verify no current fault codes are present.
  • 9
    Perform system verification: Gently tap the area near the SRS ECU and turn the steering wheel. Observe if the fault light turns off and remains off to confirm good contact.
Real-World Cases
BYD DTC AI AnalysisFrom Chinese market (translated)

Loose connection at the BYD S6 front passenger airbag connector caused B1610-00

✓
The airbag warning light on a 2014 BYD S2/S6 stayed on constantly. A diagnostic scan showed active DTC B1610-00: “Front passenger frontal airbag resistance zero”. Following the workshop manual, the technician disconnected SRS ECU connector G10 and measured the resistance across the passenger airbag circuit pins — infinite (open circuit). Further inspection found the yellow airbag connector behind the glovebox: it looked plugged in, but the locking tab wasn’t fully seated, causing an intermittent connection from vehicle vibration. The technician unplugged and reconnected the connector, making sure to hear the “click” of the lock engaging. After that, the resistance measured a normal 2.1Ω. Clearing the DTC resolved the fault.
Original source ↗
BYD DTC AI AnalysisFrom Chinese market (translated)

Internal open circuit in BYD Qin EV clock spring triggers airbag circuit fault

✓
2018 BYD Qin EV450. The airbag warning lamp illuminated intermittently when turning the steering wheel while driving, eventually staying on constantly. Fault code B1610-00 stored. Initial inspection showed the passenger airbag connector was normal; measured airbag resistance was 2.5 Ω, normal. During inspection, when turning the steering wheel, the airbag circuit resistance would momentarily go infinite. Removed the clock spring (spiral cable) beneath the combination switch and found the internal flexible ribbon cable partially fractured from long-term rotational wear. Replaced the clock spring assembly (part number: HK-347890). After multiple steering wheel rotations, resistance remained stable. Cleared the fault code; it did not return.
BYD DTC AI AnalysisFrom Chinese market (translated)

BYD E1 SRS ECU connector corrosion case after wading

✓
2019 BYD E1. The airbag warning light illuminated after driving through flood water during heavy rain. Retrieved DTC B1610-00. Inspection found water ingress traces on the carpet. The SRS ECU is mounted low under the centre console; its connector G10 showed obvious water staining and green oxidation inside. Cleaned the ECU and harness terminals using electronic cleaner, applied specialised conductive protectant (not grease), and dried thoroughly with compressed air. Also checked the passenger airbag harness insulation and found no damage. Reconnected and waterproofed the connector, cleared the fault codes, and resolved the fault. Also recommend checking the AC drain holes for blockages.
Original source ↗
Other Seal U 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: Official This information is for reference only. Always consult a qualified technician for diagnosis and repair. Do not attempt high-voltage system repairs yourself. Sources: [1]