AU
B168A00

DTC B168A00 indicates the Airbag Control Unit (ACU) detects the configuration parameters for Circuit 6 (typically the right side airbag/side curtain or right rear side airbag ignition circuit) do not match the system calibration data — Qin Plus

Safety System

DTC B168A00 indicates the Airbag Control Unit (ACU) detects the configuration parameters for Circuit 6 (typically the right side airbag/side curtain or right rear side airbag ignition circuit) do not match the system calibration data.

This is an SRS configuration fault, not a simple open or short circuit. "Invalid configuration" means the control unit's internal algorithm detects the circuit's electrical characteristics (such as squib resistance, capacitance, or internal ECU configuration code) differ from the vehicle factory settings or current hardware configuration.

This condition can prevent the airbag from deploying correctly or cause unintended deployment during a collision, constituting a Level 2 safety fault.

The B168A00 fault code on the Qin Plus indicates the airbag control unit has detected an invalid configuration for the right side airbag circuit, meaning the system settings do not match factory specifications. This medium severity fault typically occurs after replacing the control unit without proper coding or installing non-genuine airbag parts. You should visit an authorised dealer for recalibration. Typical repair cost data is available based on 5 recorded cases.
5
Cases Logged
5
Causes
Likely Causes — Qin Plus
  • 1Incorrect coding configuration or software version mismatch after replacing the Airbag Control Unit (ACU).
  • 2Installed non-genuine or incorrectly programmed side airbag module (aftermarket or used part with mismatched part number).
  • 3Modifications or accident repairs to the Circuit 6 wiring harness altered circuit resistance (e.g., installing non-OEM seat covers, crushed wiring, or oxidized connectors causing resistance to deviate from the standard 2.0Ω±0.3Ω range).
  • 4Lost or corrupted calibration data stored internally in the SRS control unit (e.g., prolonged battery disconnection, electromagnetic interference to the ECU)
  • 5Vehicle configuration changed (e.g., replacing high-spec parts with low-spec parts) without updating the ACU configuration code.
What To Do
  • 1
    Use the BYD VDS2000/VDS3100 diagnostic tool to read the complete fault codes and freeze frame data, confirm the fault status (current/history), and record the vehicle VIN and specific configuration.
  • 2
    Refer to the vehicle repair manual to identify the specific component corresponding to Circuit 6 (on the Qin PRO, this is typically the right side airbag or right curtain airbag). Inspect the component appearance, connector connection, and wiring harness integrity.
  • 3
    Disconnect the battery negative terminal, wait 3 minutes, then unplug the SRS control unit connector. Use a multimeter to measure the resistance between the two terminals of circuit 6 (standard value: 1.7-2.3 Ω), and check insulation to ground and power.
  • 4
    If resistance is abnormal, inspect the wiring harness and airbag module section by section. If resistance is normal, use the diagnostic tool to perform the 'Airbag System Configuration' function. Verify and rewrite the correct vehicle configuration code (select options such as with/without side airbags and curtain airbags based on actual vehicle configuration).
  • 5
    Perform the 'Configuration Reset' or 'ECU Initialization' procedure. Clear the fault code and perform a system self-check (turn the ignition switch to the ON position and verify the airbag warning lamp stays on for 6 seconds, then turns off). Finally, perform a simulated collision test or road test to verify the fault is resolved.
Real-World Cases
BYD DTC AI Analysis

BYD Qin Pro DM logged DTC B168A00 after fitting a salvage ACU.

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After accident repairs, technicians fitted a 2019 Qin PRO DM with a used airbag control unit from another vehicle. Once installed, the instrument panel airbag warning light stayed on, and they read DTC B168A00. Diagnosis revealed the replacement ACU stored a base model configuration code (without side curtain airbags), while the vehicle actually had side curtain airbags. They used the VDS diagnostic tool to execute the ‘Replace SRS ECU’ function, rewriting the vehicle’s VIN and high-spec model configuration code. This cleared the fault.
BYD DTC AI Analysis

Right front seat modification caused circuit 6 impedance fault

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The owner of a 2018 Qin PRO petrol variant reported the airbag warning light occasionally coming on. Retrieved DTC B168A00. Inspection found the owner had previously fitted full-coverage seat covers; the fastening clips had pierced the right front seat side airbag harness, causing circuit 6 resistance to fluctuate between 1.2–3.5Ω. Repaired the harness and remeasured resistance at 2.0Ω. Cleared the DTC and no faults returned after 3 days of use.
BYD DTC AI Analysis

Software version too low to recognise new components

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After the dealership replaced the right side airbag module, a 2019 Qin PRO DM set DTC B168A00. Replacing the module multiple times did not resolve the issue. Inspection found the ACU software was an early 2018 version, while the new airbag module had an improved igniter design. Solution: Upgraded the SRS control unit software to the latest version (post-October 2019), reconfigured the loop parameters, and resolved the fault.
BYD DTC AI Analysis

Oxidised SRS connector on flood-damaged vehicle caused configuration failure

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Repaired a Qin PRO DM that had been driven through water. Afterwards, the airbag warning light came on with DTC B168A00. Found water inside the lower right B-pillar SRS harness connector; oxidised and blackened pins increased contact resistance to 4.5 Ω, causing the control unit to misread as 'invalid configuration'. Cleaned the connector and applied conductive paste; resistance then measured 1.9 Ω. Cleared the fault code and the system returned to normal.
BYD DTC AI Analysis

A wiring harness bridge repair after an accident caused a fault.

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While repairing right-side accident damage on a Qin PRO, a workshop incorrectly cross-connected the Loop 6 (side airbag) and Loop 5 (the other side airbag) wiring harnesses. This caused the ACU to detect that the electrical characteristics of Loop 6 did not match the stored configuration template. After reconnecting the harnesses according to the circuit diagram to ensure the left and right circuits were independent and had normal resistance, the fault code cleared automatically.
Other Qin Plus 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.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.B110BDTC B110B indicates a fault in the internal air pump (sampling pump) of the PM2.5 air quality detector. This pump draws cabin or outside air into the PM2.5 sensor detection chamber, enabling the laser scattering sensor to measure real-time particulate matter concentration. The air conditioning controller (or BCM) sets this DTC upon detecting an open or short circuit in the pump drive circuit, or abnormal current caused by a seized pump motor. This fault disables the "Green Clean" system, causes the instrument cluster air quality display to read abnormally or disappear, and disables the automatic fresh air/recirculation switching function. It does not affect the vehicle powertrain or core thermal management functions.B173A1ADTC B173A1A indicates the right middle-row side airbag (typically located on the side of the right second-row seat or inside the C-pillar trim panel) igniter circuit resistance measures 0 Ω. In the Supplemental Restraint System (SRS), normal airbag igniter resistance ranges between 2.0 and 5.0 Ω. A resistance of 0 Ω indicates a short to ground or a short between circuit wires, preventing the Airbag Control Unit (ACU) from establishing a normal monitoring circuit. This safety-critical fault prevents the airbag from deploying during a collision, continuously illuminates the instrument panel SRS warning lamp, and may force the entire airbag system into fail-safe mode.B173BDTC B173B indicates an abnormal electric A/C compressor speed feedback signal or a communication fault between the compressor controller and the motor. In BYD new energy models (e.g., Tang, Song, Qin, and Yuan series), this DTC belongs to the HVAC subsystem within the Body Control system and specifically involves the electric compressor closed-loop control circuit. The ECU sets this DTC when the compressor controller (IPM) fails to receive a valid pulse signal from the Hall speed sensor for more than 3 continuous seconds, or when the deviation between the detected actual speed and the target commanded speed exceeds the calibrated threshold (typically >500 rpm). This fault forces the A/C system into fail-safe mode and stops compressor operation. Symptoms include a complete lack of cooling, intermittent cooling, or a sharp decrease in cooling performance. The instrument cluster A/C warning lamp may also illuminate. Prolonged operation with this fault can degrade high-voltage system insulation or cause controller overcurrent damage.
Common problems reported for Qin Plus →Qin Plus 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.