AU
B160C-00

DTC B160C-00 indicates the SRS (Supplemental Restraint System) control module detects the driver frontal airbag (steering wheel airbag module) igniter (squib) circuit resistance exceeds the calibrated upper limit — Seal U

Safety System

DTC B160C-00 indicates the SRS (Supplemental Restraint System) control module detects the driver frontal airbag (steering wheel airbag module) igniter (squib) circuit resistance exceeds the calibrated upper limit.

Normal BYD Qin series airbag igniter resistance is 2.0-3.0 Ω.

The ECU triggers this fault when it detects the resistance continuously exceeds the threshold (typically >5 Ω or an open circuit).

This hard fault means the airbag may fail to deploy normally (fail-safe mode) or delay deployment during a collision, severely compromising driver passive safety.

Poor contact, wiring oxidation, a partial open circuit, or igniter aging causes the abnormal increase in circuit resistance.

5
Cases Logged
5
Causes
Likely Causes — Seal U
  • 1Clock spring (spiral cable) internal open circuit or poor contact: Frequent steering wheel rotation causes fatigue and breakage of the internal flat cable. This is the most common point of failure in the BYD Qin series.
  • 2Airbag module connector loose or oxidized: Poor contact at the yellow connector below the steering wheel (usually marked DAB) increases contact resistance.
  • 3Airbag inflator internal open circuit: Aging of the electric detonator inside the airbag module or a manufacturing defect causes an abnormal increase in internal resistance.
  • 4Wiring harness wear or partial open circuit: Repeated bending of the wiring harness near the steering column during steering causes partial breakage of the copper strands without completely opening the circuit.
  • 5SRS control module sampling circuit fault: Internal ECU A/D converter or sampling resistor is faulty, causing false detection (rule out external wiring faults before confirming).
What To Do
  • 1
    Safety preparation: Switch the vehicle OFF, disconnect the low-voltage battery negative terminal, and wait at least 3 minutes to fully discharge the SRS capacitor. Do not use a low-impedance multimeter to directly measure the airbag circuit.
  • 2
    Visual inspection: Inspect the yellow airbag connector (DAB connector) below the steering wheel for looseness, backed-out pins, water ingress, or oxidation. Inspect the clock spring housing for damage.
  • 3
    Remove the airbag module: Use the special tool to remove the driver airbag (observe ESD precautions). Disconnect the airbag connector. Use a high-impedance digital multimeter (≥10 MΩ) to measure the resistance between the two terminals of the airbag igniter. The standard value is 2.0-3.0 Ω. If the resistance is infinite or >5 Ω, replace the airbag module.
  • 4
    Inspect the clock spring: Disconnect the clock spring from the body wiring harness. Measure the continuity between the corresponding pins on the steering wheel side and the body side of the clock spring. Turn the steering wheel lock-to-lock; the resistance must be <1Ω without fluctuation. If the resistance is unstable or too high, replace the clock spring.
  • 5
    Harness continuity test: Measure the circuit resistance from the SRS ECU to the clockspring body-side connector; resistance must be <1 Ω. Measure the insulation resistance to ground; resistance must be >1 MΩ. This rules out potential partial open or short circuits in the wiring.
  • 6
    Replacement verification: If the above checks are normal, substitute a known-good clock spring or airbag module to confirm if the fault transfers.
  • 7
    System reset: After repair, reconnect all components and turn on the power. Use a dedicated diagnostic tool (such as BYD ED400 or Launch X431) to clear the fault code. Perform 'SRS system self-diagnosis' and 'configuration verification'. Verify B160C-00 does not return and the airbag warning light turns off.
  • 8
    Function check: Perform a road test, turn the steering wheel lock-to-lock, and observe whether the instrument cluster airbag warning light illuminates intermittently to confirm the fault is completely resolved.
Real-World Cases
BYD DTC AI AnalysisFrom Chinese market (translated)

Internal open circuit in clock spring causing high resistance

✓
Vehicle: Qin EV300 2017 model, 82,000 km. The owner reported the airbag warning light stays on. Retrieved fault code B160C-00 (driver airbag resistance too high). Measured the airbag module itself at 2.3 Ω (normal). Measured resistance between the corresponding pins on the body side and steering wheel side of the clock spring: 5.8 Ω with the wheel centred, reading infinite (open circuit) at full left lock. Disassembled the clock spring and found the internal flat cable partially broken from prolonged rotation. Replaced the clock spring with a genuine part (part number: BYD- clock spring assembly), which cleared the fault. Analysis: The Qin-series clock spring is designed for roughly 80,000–100,000 steering cycles; ride-hail cars in heavy use tend to fail early.
BYD DTC AI AnalysisFrom Chinese market (translated)

Airbag connector oxidised, poor contact

✓
Model: Qin 100 2017, mileage 65,000 km, vehicle in humid southern region. Symptom: Airbag warning light illuminated intermittently, more frequent in wet weather. Diagnosis found B160C-00 as a historical fault code; current resistance measurements fluctuated between 2.5–8 Ω. Inspection revealed green oxidation on pins inside the yellow DAB connector beneath the steering wheel, and a loose connector locking clip. Cleaned pins with electronic cleaner, applied conductive paste, and replaced the locking clip. Resistance stabilised at 2.4 Ω. One-month follow-up: no recurrence. Recommendation: For water-exposed vehicles or high-humidity environments, pay close attention to connector seal integrity.
BYD DTC AI AnalysisFrom Chinese market (translated)

Airbag module internal igniter degraded.

✓
Model: Qin EV450 2018, 120,000 km. After collision repair, the airbag warning light stays on. DTC B160C-00 present. Found the driver airbag did not deploy but sustained impact. Disconnected the driver airbag module and measured its resistance: 12 Ω (excessively high). Determined internal igniter connections fractured from the impact. Replaced the driver airbag module (also replace the clock spring, as the old unit may have been damaged in the collision). After programming and matching, the fault was resolved. Tip: On vehicles after a collision, check igniter resistance for impact damage even if airbags did not deploy.
BYD DTC AI AnalysisFrom Chinese market (translated)

Worn steering column wiring harness caused intermittent open circuit.

✓
Vehicle: 2017 Qin 80, 90,000 km. Customer reported the airbag warning light occasionally flickering when turning the steering wheel. Static resistance measured normal at 2.6Ω, but when turning the wheel quickly left and right, resistance instantly jumped above 20Ω. Removed the steering column shroud and found the clock spring-to-body harness transition section had worn insulation at the mounting bracket from long-term chafing, with some copper wires broken and only a few strands remaining connected. Repaired the harness: cut out the damaged section, crimped new terminals, and added anti-abrasion sleeving. Fault fixed. For intermittent faults like this, use the wiggle test to pinpoint.
BYD DTC AI AnalysisFrom Chinese market (translated)

SRS control module software false positive

✓
Vehicle: 2017 BYD Qin EV300, 40,000 km. No accident history. Airbag warning light suddenly came on. DTC B160C-00 stored. Measured airbag circuit resistance throughout; readings normal at 2.2 Ω. Wiring showed no abnormalities. Checked BYD Technical Service Bulletin TSB-2018-SRS-03; it identifies an SRS software calibration issue on early Qin EV300 models that causes false resistance readings during voltage fluctuations. Updated SRS control module software to V2.3.1 or higher. Fault cleared. This case serves as a reminder: after ruling out hardware faults, consider software calibration and ECU sampling circuit issues.
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]