AU
B160111

DTC B160111 indicates a short to ground in the driver frontal airbag (DAB) igniter circuit — Atto 8

Safety System

DTC B160111 indicates a short to ground in the driver frontal airbag (DAB) igniter circuit.

The SRS (Supplemental Restraint System) airbag igniter utilizes a low-resistance circuit (typically 2.0–3.0Ω).

The ACU (Airbag Control Unit) registers a short to ground when it detects circuit resistance below the threshold (<0.8Ω) or direct continuity to body ground.

Wiring insulation failure or an internal component short circuit causes this fault, grounding the igniter circuit abnormally.

Effects include: 1) the airbag may fail to deploy during a collision (current bypasses to ground); 2) electrostatic discharge or electromagnetic interference may cause unintended deployment in extreme cases; 3) the system enters fail-safe mode, disabling all airbag functions.

This constitutes a Level 1 active safety system fault.

Remove the vehicle from service immediately; the driver airbag serves as the final line of defense, and its failure drastically increases the risk of injury or fatality during an accident.

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Cases Logged
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Causes
Likely Causes — Atto 8
  • 1A worn or broken flat ribbon cable inside the clock spring causes the conductor to contact the metal steering wheel frame and short to ground. Long-term full-lock steering fatigues the coiled cable, causing this common fault in high-mileage BYD Qin/E Series vehicles.
  • 2Water ingress and corrosion at the airbag wiring harness connector (usually located under the steering wheel or inside the steering column trim), especially due to a blocked A/C drain hose or defective front windshield seal. The resulting electrolyte shorts the pins to body ground.
  • 3Improper airbag removal or installation causes tools to scratch the wiring harness insulation, or improperly securing the harness after accident repairs allows metal bracket edges to chafe through the outer sheath, creating a short to ground.
  • 4Internal short circuit due to insulation failure of the airbag module (inflator) igniter bridge wire. Though rare, this occurs in high-temperature, high-humidity environments or with poor-quality reconditioned airbags.
  • 5An ACU internal drive circuit fault or bent connector pins cause the diagnostic circuit to falsely detect a short to ground. Isolate the cause by measuring harness-side resistance and the ACU-side output waveform.
What To Do
  • 1
    Safety preparation: Turn off the ignition, disconnect the 12V battery negative terminal, and wait at least 90 seconds to fully discharge the SRS capacitor and prevent accidental airbag deployment. Discharge static electricity from your body before disconnecting the airbag connector.
  • 2
    Static visual inspection: Check the steering wheel area for signs of removal or installation, water stains, mildew odor, or exposed wiring harnesses. Specifically inspect the wiring harness sleeve below the steering column for damage. Check the airbag connector (yellow marking) for looseness or green copper corrosion.
  • 3
    Resistance measurement diagnosis: Set the multimeter to the ohms scale, disconnect the airbag module connector, and measure the resistance of the DAB+ and DAB- circuits to body ground individually. The normal reading is infinity (OL). A low resistance reading of 0-5Ω confirms a short to ground.
  • 4
    Clock spring isolation test: Remove the steering wheel (using a special puller), disconnect the upper and lower clock spring connectors, and measure the resistance to ground at the clock spring upstream (ACU side) and downstream (airbag side) separately. If the upstream is normal and the downstream is shorted, replace the clock spring assembly.
  • 5
    Harness routing inspection: If the clock spring is normal, trace the main wiring harness down the steering column. Inspect the harness grommet at the firewall pass-through hole for wear. If necessary, gently move the harness with a probe and monitor the multimeter for resistance fluctuations to locate the short circuit.
  • 6
    Component replacement and verification: After replacing the faulty component (clock spring, wiring harness, or airbag module), leave the airbag disconnected. Connect an airbag simulator (2.7Ω resistor) to the ACU connector, clear the fault code, perform an ignition self-check, and verify normal system operation.
  • 7
    Final assembly test: Remove the simulator, restore all connections, and reconnect the battery. Perform an SRS system self-check using VDS or X431. Confirm B160111 is a history code and no current codes exist. Perform a crash simulation test (professional equipment required) to verify circuit resistance is within the standard range.
Real-World Cases
BYD DTC AI AnalysisFrom Chinese market (translated)

BYD Qin Pro airbag warning light on after driving through water

✓
2019 Qin Pro DM, 45,000 km. After wading through deep water during heavy rain, the airbag warning light stayed on the next day. Retrieved DTCs B160111 and B161111 (passenger airbag short to ground). Disassembly revealed water inside the yellow 2-pin connector beneath the steering column; resistance between pin 1 (DAB-) and the housing measured 0.3 Ω. Repair: Flushed the connector with electronic cleaner, dried it with compressed air, applied conductive anti-corrosion grease, and replaced the waterproof O-ring. Because the airbag module was not damaged, resistance returned to normal after the repair, clearing the fault.
BYD DTC AI AnalysisFrom Chinese market (translated)

E2: Clock spring wear in a ride-hailing vehicle caused an intermittent short circuit.

✓
2020 BYD E2 ride-share vehicle, 128,000 km. Airbag light came on intermittently, more often when cornering. Diagnostics showed DTC B160111 as an intermittent current code. Removed the steering wheel to inspect the clock spring and found a 0.5 mm break in the internal flat ribbon cable at the 3-turn winding position, with bare copper wire contacting the steering wheel frame. Cause: cable fatigue from prolonged stationary steering. Replaced the clock spring assembly (part no. SCE-5823800) — fault cleared. Owner advised to avoid holding the steering wheel on full lock for more than 3 seconds.
BYD DTC AI AnalysisFrom Chinese market (translated)

Improperly secured wiring harness after accident repair caused a short circuit.

✓
2018 BYD Qin Pro petrol. DTC B160111 appeared one week after front collision repairs. We found the repairer trapped the airbag wiring harness under the steering column mounting bracket while refitting the dashboard. The metal bracket edge cut through the harness insulation, causing the black wire (ground) to contact the yellow wire (DAB+). We repaired the damaged harness, wrapped it with three layers of high-temperature tape, rerouted the wiring and added a rubber protective sleeve, ensuring at least 20 mm clearance from sharp metal components.
BYD DTC AI AnalysisFrom Chinese market (translated)

Airbag module internal igniter short circuit

✓
2019 BYD Qin EV, no accident history. Airbag warning light illuminated suddenly during normal use. Scan tool showed active DTC B160111 and could not be cleared. Disconnected the airbag connector; measured harness-side resistance to ground — infinite (normal). Measured resistance across the two pins of the airbag module connector (component side): 0.2Ω (normal ~2.3Ω). Found an internal short in the airbag igniter. Replaced the driver airbag module (clock spring also replaced to ensure good contact). Fault resolved. Cause likely a batch quality issue in the igniter, or internal insulation degradation from long-term high-temperature exposure.
Other Atto 8 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]