AU
B160C1B

This fault code indicates the driver front airbag (DAB) igniter (gas generator) resistance exceeds the normal threshold range set by the SRS control module (typically 2 — Seal U

Safety System

This fault code indicates the driver front airbag (DAB) igniter (gas generator) resistance exceeds the normal threshold range set by the SRS control module (typically 2.0–3.0 Ω, depending on the vehicle model). "High resistance" usually indicates a high-impedance point in the circuit.

Causes include poor wiring connections, oxidized connectors, poor internal contact in the clock spring (spiral cable), or an aging airbag igniter.

This active safety system fault causes the SRS control module to classify the driver airbag as unreliable.

This condition may prevent airbag deployment during a collision, or in some cases, continuously illuminate the warning light and store a fault code, severely compromising passive safety protection.

4
Cases Logged
5
Causes
Likely Causes — Seal U
  • 1Internal open circuit or poor contact in the clock spring (spiral cable/clockspring): Frequent steering wheel rotation may cause fatigue breakage or increased contact resistance in the internal flat cable, increasing airbag circuit resistance.
  • 2Poor contact at the airbag module connector: The connector connecting the driver airbag to the wiring harness (usually located inside or beneath the steering wheel) exhibits oxidation, looseness, backed-out pins, or enlarged pin holes, increasing contact resistance.
  • 3Airbag igniter internal fault: Aging, a dry solder joint, or a partial open circuit in the gas generator igniter bridge wire causes the resistance to exceed the calibrated range.
  • 4Harness wear or poor connection: The wiring harness between the SRS ECU and the driver airbag exhibits pinching, wear, moisture corrosion, or poor connector contact, especially in moving areas near the steering column.
  • 5SRS control module internal sampling circuit fault: The resistance detection circuit inside the control module fails, falsely reporting high resistance (relatively rare, but rule this out).
What To Do
  • 1
    Safety preparation: Set the vehicle to OFF, disconnect the 12V battery negative terminal, and wait at least 90 seconds to fully discharge the SRS system capacitors and prevent accidental airbag deployment.
  • 2
    Fault confirmation: Use a dedicated BYD diagnostic tool (VDS or ED400) to read the fault code. Confirm B160C1B is a current DTC, not a history DTC, and record the freeze frame data.
  • 3
    Visual inspection: Remove the covers on both sides of the steering wheel. Check the driver airbag module connector for looseness, oxidation, or foreign matter. Check the connection status of the clock spring connector.
  • 4
    Resistance measurement: Disconnect the airbag module connector. Use a digital multimeter to measure the resistance between the two airbag igniter terminals (must be within the specified range, typically 2.0-3.0 Ω). Simultaneously measure the insulation resistance between the connector terminals and body ground (must be greater than 1 MΩ).
  • 5
    Clock spring inspection: Remove the steering wheel (use the special tool and note the alignment marks). Measure the continuity and resistance of each clock spring circuit. Turn the steering wheel and check if the resistance remains stable. If the reading fluctuates or the resistance is too high, replace the clock spring.
  • 6
    Harness continuity test: Test harness continuity between the SRS ECU and the airbag connector. Focus on harness bends near the steering column. Measure total circuit resistance; it must be less than 1 Ω.
  • 7
    Replacement verification: If the measurement shows abnormal resistance, replace the clock spring first. If the resistance is normal but the fault persists, perform a substitution test using a known-good airbag module. (Note: Connect the system correctly during testing. Do not use an ordinary resistor as a substitute in the airbag circuit.)
  • 8
    System reset: After completing the repair, reconnect all connectors (listen for the locking click). Connect the battery. Use the diagnostic tool to clear the fault code and perform an SRS system self-check. Confirm the fault code does not return and the airbag warning light turns off normally.
Real-World Cases
BYD DTC AI AnalysisFrom Chinese market (translated)

Internal open circuit in Qin Pro DM clock spring causing high resistance

✓
A 2019 Qin Pro DM came in with the airbag warning light on steady. DTC B160C1B was stored. After removing the steering wheel, the driver airbag read 2.3 Ω (normal), but resistance from the lower clock spring terminal to the airbag connector was open. Disassembling the clock spring revealed a fatigue fracture of the internal ribbon cable at the rotational centre. Replacing the clock spring (part number possibly FA-XXXXX) restored normal circuit resistance. Clearing the DTC resolved the fault.
BYD DTC AI AnalysisFrom Chinese market (translated)

Oxidised airbag connector causing intermittent high resistance

✓
2018 Qin Pro petrol. Customer reported airbag warning light occasionally illuminated. Scan tool retrieved historic DTC B160C1B. Inspection found slight oxidation and looseness in driver-side airbag connector (yellow connector). Cleaned connector terminals with electronic contact cleaner and adjusted connector locking tab for a tight connection. Applied conductive grease to prevent further oxidation. Reassembled and road tested over one week; fault did not recur. Confirmed intermittent high-resistance fault caused by poor contact.
BYD DTC AI AnalysisFrom Chinese market (translated)

Modified steering wheel damaged the airbag harness

✓
A 2019 BYD Qin PRO DM logged DTC B160C1B after the owner fitted an aftermarket racing steering wheel and later refitted the original. Inspection revealed the airbag harness had been overstretched during the modification, fracturing some of the internal copper conductors while the outer insulation remained intact and creating a high-resistance path. Harness resistance measured 5.8Ω (excessive). Replaced the harness section from the clock spring to the airbag (or repaired the harness), restoring resistance to 2.1Ω and clearing the fault. Advised the owner to avoid non-professional modifications to the airbag system.
BYD DTC AI AnalysisFrom Chinese market (translated)

Airbag module internal igniter aging

✓
A 2018 Qin PRO with 80,000 km had DTC B160C1B. Checked the wiring harness and clock spring – both normal. Direct measurement at the airbag module connector gave 4.5Ω (outside normal range). The cause was aging of the ignition bridge wire inside the gas generator, increasing resistance. Airbag modules are safety components, so disassembly and repair are not permitted. Replaced the complete driver airbag module, ensuring the part number matched (e.g., DAB-XXXXX). Fault code cleared, system returned to normal.
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]