AU
B1630-00

DTC B1630-00 indicates the SRS (Supplemental Restraint System) control module detects an open circuit or high resistance in the right front seat side airbag module circuit — Atto 3

Safety System

DTC B1630-00 indicates the SRS (Supplemental Restraint System) control module detects an open circuit or high resistance in the right front seat side airbag module circuit.

The resistance exceeds the calibrated range (typically >10Ω).

This represents a hard fault in the airbag system; the right front seat side airbag fails to deploy during a side-impact collision.

The system enters fail-safe mode and continuously illuminates the instrument cluster airbag warning light.

Potential causes include an open wiring circuit, a disconnected connector, an open airbag squib, or excessive contact resistance.

4
Cases Logged
5
Causes
Likely Causes — Atto 3
  • 1Loose or completely disconnected SRS-specific yellow connector under the seat: Vibration from sliding the seat or passenger kicks can loosen the under-seat airbag wiring harness connector (usually equipped with a shorting bar protection mechanism).
  • 2Wiring harness worn and broken at the seat slide rail: During fore-and-aft seat adjustment, the side airbag wiring harness (transition section from the body floor harness to the seat) bends repeatedly at the slide rail, causing fatigue fractures in the internal copper wires while the outer insulation remains intact.
  • 3Airbag module internal open circuit: Open circuit in the side airbag assembly igniter (squib) or damaged spiral cable, typically caused by aging or failure to replace the airbag after a previous accidental deployment.
  • 4Connector terminal oxidation or poor contact: Vehicle wading or damp environments cause oxidation of the plug terminals under the seat, creating high contact resistance (>2Ω) that the ECU detects as a disconnection.
  • 5Not reset after previous repair: After replacing the seat cover, repairing the seat heater, or removing and installing interior trim, the technician failed to reconnect the airbag connector or remove the shorting bar.
What To Do
  • 1
    Safe power-down: Turn off the ignition switch, disconnect the 12V battery negative terminal, and wait at least 90 seconds (to fully discharge the SRS capacitor). Do not operate any electrical equipment during this time.
  • 2
    Visual inspection and location: Move the right front seat to the fully forward position. Inspect the yellow SRS connector under the seat (usually located on the inner or rear side, equipped with a double-locking mechanism). Confirm the connector is fully inserted with an audible locking 'click'. Verify the shorting bar has sprung open.
  • 3
    Resistance measurement verification: Use a multimeter to measure the airbag circuit resistance. Disconnect the airbag connector. Measure the harness-side resistance at the ECU end (must be infinite to rule out a short to ground). Measure the module resistance at the airbag side (standard value: 2.0-3.0 Ω; if >10 Ω, replace the airbag module).
  • 4
    Wiring harness continuity check: Inspect the wiring harness corrugated conduit from the seat to the vehicle floor, focusing on the bend at the seat slide rail. Peel back the tape and check for broken wires, exposed copper strands, or pinch marks. Repair the wiring harness if necessary and rewrap it.
  • 5
    Clean and secure: If the connector shows oxidation or corrosion, clean the terminals with electrical contact cleaner and apply conductive grease. Reconnect the connector, then secure the wiring harness to the seat frame with cable ties to prevent interference with moving parts.
  • 6
    System reset test: Reconnect the battery. Turn the ignition switch to the ON position. Use the diagnostic tool to clear the fault code. Observe if the instrument cluster SRS warning lamp turns off after 6 seconds. Read the data stream to confirm the right front side airbag status is 'Normal' (resistance value within the normal range).
  • 7
    Function verification: Use the diagnostic tool to perform the 'Airbag System Self-check' or 'Crash Sensor Test' and confirm no current fault codes are present. Perform a seat forward and backward movement test to confirm the fault does not recur.
Real-World Cases
BYD DTC AI AnalysisFrom Chinese market (translated)

Frequent seat adjustment caused the connector to work loose

✓
A 2018 BYD Qin EV450 came in with the airbag warning light on constantly. Retrieved DTC B1630-00. Found the yellow SRS connector beneath the right front seat had loosened about 2mm, and the locking click was not fully heard. The cause: the owner frequently allowed rear passengers to adjust the seat, gradually working the connector loose. Repair: reconnected the connector, confirmed the double-locking mechanism was fully seated, and secured the wiring harness to the seat spring with a cable tie to prevent movement. Cleared the fault code; normal operation returned.
BYD DTC AI AnalysisFrom Chinese market (translated)

Seat rail chafed wiring harness - open circuit

✓
A 2019 BYD E1 with 80,000 km on the odometer displayed an airbag fault on the instrument cluster. The scan tool showed DTC B1630-00. Disassembly and inspection revealed the right front seat side airbag harness, at the bend behind the slide rail, had its outer insulation intact while both internal copper wires were completely broken. The cause was fatigue failure from the harness rubbing against the metal slide rail edge during repeated fore-aft seat movement. Repair: Replaced the seat wiring harness assembly (0.5mm² cross-section or larger, high-temperature rated), rerouted the harness to add slack, and fitted a rubber protective sleeve at the bend.
BYD DTC AI AnalysisFrom Chinese market (translated)

Connector oxidised after water ingress, causing poor contact

✓
A 2017 Qin 100 suffered water ingress in the right front carpet due to a blocked sunroof drain tube, causing the airbag warning light to come on. Logged DTC B1630-00. Inspection found significant water staining inside the connector beneath the seat, green oxide on the copper terminals, and contact resistance of 15 Ω (should be <1 Ω). Repair: disconnected the connector, cleaned the terminals with anhydrous alcohol, dried them, applied electrical contact protectant, and replaced the connector housing if needed. Also cleared the sunroof drain tube and air-dried the carpet to prevent the carpet from getting damp again.
BYD DTC AI AnalysisFrom Chinese market (translated)

Did not reconnect the airbag connector after replacing the seat cover

✓
A 2018 Qin EV450 developed an airbag warning light after a detailing shop reupholstered the seats in leather. Scanned code B1630-00. Inspection found the right front seat side airbag connector fully disconnected, with the shorting bar in the closed position (used during repairs to prevent accidental deployment from static electricity). The shop admitted they disconnected the plug during seat removal and refitting and forgot to reconnect it. Solution: Reconnected the plug and confirmed it locked securely. Advised the owner that SRS repairs require qualified technicians.
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: 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]