AU
B168000

DTC B168000 indicates the SRS (Supplemental Restraint System) control module detected a communication interruption or physical disconnection between the Passenger Airbag Disable (PAD) switch and the main control unit — Atto 8

Safety System

DTC B168000 indicates the SRS (Supplemental Restraint System) control module detected a communication interruption or physical disconnection between the Passenger Airbag Disable (PAD) switch and the main control unit.

The PAD switch typically mounts in the center console or near the glovebox to manually disable the front passenger airbag (e.g., when installing a child safety seat).

The SRS module triggers this fault code if it fails to receive the switch resistance signal (typically a specific resistance range, such as 2kΩ-5kΩ indicating different states) within a predetermined time, or if it detects an open circuit (infinite resistance).

This fault forces the front passenger airbag system into fail-safe mode and continuously illuminates the instrument cluster airbag warning lamp.

During a collision, the front passenger airbag may fail to deploy or exhibit unpredictable behavior, severely compromising passive safety.

The B168000 fault code on the Atto 8 indicates a communication break between the Passenger Airbag Disable (PAD) switch and SRS control module, disabling the front passenger airbag and illuminating the warning light. Severity is medium. Common causes include loose wiring connectors or chafed/broken wires near the center console or seat rails. An authorised dealer should inspect and repair the system. Typical repair cost data is available based on four recorded cases.
4
Cases Logged
5
Causes
Likely Causes — Atto 8
  • 1Loose, disconnected, or poor contact at the front passenger airbag deactivation switch wiring harness connector, especially due to incorrect reconnection after glove box or center console removal and installation.
  • 2Long-term chafing of the floor or instrument panel wiring harness against moving parts (such as the front passenger seat slide rail or hinges) causes an open circuit, or the internal copper wire breaks while the insulation remains intact (hidden open circuit).
  • 3Internal contact oxidation, spring failure, or mechanical binding within the airbag deactivation switch assembly causes the resistance value to fall outside the standard range (normally 2.5kΩ-4.8kΩ, depending on switch position).
  • 4A short to ground or short to power in the communication circuit between the SRS control module and the switch causes abnormal signal voltage (normal signal voltage is a 0-5V pulse or within a specific analog voltage range).
  • 5A loose front passenger airbag module connector (located inside the dashboard) triggers a related communication fault when sharing a ground or signal wire with the switch circuit.
What To Do
  • 1
    Connect the BYD VDS2000 or Launch X-431 diagnostic tool. Access the SRS system to read DTC B168000 and freeze frame data. Confirm the vehicle status at the time of the fault (voltage, temperature, mileage). Attempt to clear the DTC to determine if the fault is intermittent.
  • 2
    Visually inspect the front passenger airbag deactivation switch near the center console or glove box. Confirm the switch body has no physical damage. Verify the wiring harness connector is fully seated and the locking mechanism is securely engaged. If necessary, disconnect the connector and inspect the terminals for push-out, oxidation, or deformation.
  • 3
    Measure the switch body resistance with a multimeter: in the 'ON' (airbag enabled) position, the resistance should be approximately 2.0-2.5 kΩ; in the 'OFF' (airbag disabled) position, it should be approximately 4.0-4.8 kΩ (refer to the model-specific workshop manual for standard values). If the resistance is infinite or zero, replace the switch body.
  • 4
    Disconnect the SRS control module connector and switch connector. Measure harness continuity between them. Closely inspect the floor harness for wear at the front passenger seat slide rail and the dashboard frame pinch points. Harness resistance must be less than 1 Ω. Insulation resistance to ground must be greater than 10 MΩ.
  • 5
    Check the SRS control module power supply (constant +B) and ground (GND) for secure connections. Inspect the module connector pins for green copper corrosion. Clean with electrical contact cleaner if necessary.
  • 6
    After repairing or replacing the faulty wiring harness/switch, reconnect all connectors and clear the fault code. Turn the ignition switch to the ON position and verify the airbag warning lamp on the instrument cluster turns off after 6 seconds. Perform a system self-check: cycle the front passenger airbag deactivation switch 3 consecutive times. Confirm the SRS module correctly identifies the status change and the fault code does not return.
  • 7
    Perform final verification: Use the diagnostic tool to read the SRS system data stream. Verify the 'Passenger Airbag Status' matches the actual switch position. Perform a simulated crash test (diagnostic tool function only; does not trigger the actual airbag) to confirm normal system response.
Real-World Cases
BYD DTC AI Analysis

Aftermarket centre console modification loosened the switch connector

✓
A 2019 BYD E2 owner reported that the airbag warning light on the instrument cluster had suddenly illuminated. Technicians used a VDS scan tool to retrieve DTC B168000. When asked, the owner said a large centre touchscreen had been installed at a modification shop the previous day. Disassembly and inspection found that during centre console removal, the installers had pulled the 2-pin connector for the passenger airbag disable switch (located to the right of the glovebox) loose, breaking the locking tab. Technicians reconnected the connector and used cable ties to secure the wiring harness routing. The fault was resolved after clearing the DTC. Mark all airbag-related wiring harnesses during future modifications to prevent rough disassembly and installation.
BYD DTC AI Analysis

Qin EV wiring harness open circuit caused by seat rail wear

✓
2019 Qin EV, 30,000 km. DTC B168000 occurring intermittently, with increased frequency on rough roads. Initial inspection found no connector faults. Removed the passenger seat and found that the floor harness had chafed through its insulation at the seat rail mounting point from long-term friction. Of the 3 internal wires, 2 had completely broken (copper strands broken but the insulation intact, causing an intermittent open circuit). Stripped back the harness, re-soldered the broken wires, insulated with double-layer heat-shrink tubing, rerouted the harness to clear the seat rail travel path, and added corrugated tubing for protection. Fault completely eliminated.
BYD DTC AI Analysis

E3 airbag disable switch failed due to internal oxidation

✓
2020 BYD E3, 2 years old, operated in a southern coastal city. DTC B168000 persisted and would not clear. Power supply at the switch harness connector measured 12 V (normal), but the signal line showed no change. Removed the switch assembly (right side of centre console, keyhole or button type) and disassembled it. Internal contacts were severely oxidised from humidity; resistance measured in the megaohm range (normal: kiloohm range). Fitted a new passenger airbag deactivation switch (part number may be K85-XXXXXX, verify against specific vehicle configuration). Performed recalibration and the fault cleared. Advised the owner to avoid placing liquids in the cup holder to prevent fluid ingress into the switch.
BYD DTC AI Analysis

Qin EV poor grounding after accident repair

✓
2019 Qin EV. Following front collision repairs, the SRS system stored DTC B168000 and multiple communication faults. Technicians found that the repair shop had not properly tightened the SRS control module ground wire (typically located on the left side of the dashboard frame) during the accident repair. This caused unstable power supply to the module and triggered a false warning for passenger airbag switch disconnection. They reconditioned the ground wire contact surface by grinding away paint and oxidation, then used a torque wrench to tighten the ground bolt to the specified torque (usually 8–10 N·m). After clearing all fault codes, B168000 did not reappear. This case is a reminder that accident repairs must strictly follow circuit diagrams to restore all ground points.
Other Atto 8 Fault Codes
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.B110A02DTC B110A02 indicates the thermal management master control unit (HVAC ECU) or body control module (BCM) failed to receive valid CAN data frames from the PM2.5 air quality sensor over consecutive communication cycles (typically 500ms per cycle). The sensor typically mounts at the HVAC unit air inlet or behind the glove box and transmits real-time particulate concentration data (unit: μg/m³) to the HVAC controller via the CAN bus. The fault is essentially a communication link layer timeout. Potential causes include physical layer wiring faults, sensor power supply failures, sensor internal MCU lockup, or CAN network topology damage. Although this non-critical fault does not directly affect driving safety, it disables the intelligent air purification strategy and the automatic fresh air/recirculation switching function. In extreme cases, it triggers a thermal management system degraded mode, limiting compressor power or fixing the air flap position.B110B07This fault code indicates abnormal operation of the internal air pump (sampling pump) in the PM2.5 air quality detection module. The PM2.5 detector uses the laser scattering principle to measure particulate concentration and requires a built-in air pump to draw ambient air into the detection chamber at a constant flow rate. The ECU sets this code when it detects an open or short in the air pump drive circuit, abnormal current (stall or free-running), or abnormal speed feedback. This fault causes the automatic air conditioning system to lose air quality sensing capability, preventing automatic switching between fresh air and recirculation modes. The instrument cluster air quality display may show '--' or a fixed value, but the fault does not affect the vehicle powertrain or basic air conditioning cooling and heating functions.B173CDTC B173C indicates the Supplemental Restraint System (SRS) detects the Right Second Row Side Airbag squib circuit resistance exceeds the calibrated threshold (typically >4.5Ω). This fault is an active diagnostic result of the SRS system, indicating a high-resistance condition in the circuit between the Airbag Control Unit (ACU) and the airbag module. Causes for excessive resistance include increased contact resistance, a partially broken wiring harness, terminal oxidation, or an aging squib wire inside the airbag module. This fault causes the system to mark the airbag circuit as 'unreliable', meaning the airbag may fail to deploy during a collision. The fault typically illuminates the instrument cluster airbag warning light (SRS light) continuously, and some models also sound a warning buzzer.
Common problems reported for Atto 8 →Atto 8 overview →
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.