AU
B168B00

DTC B168B00 indicates the SRS (airbag system) control module detects invalid configuration parameters for Airbag Loop 7 — Seal U

Safety System

DTC B168B00 indicates the SRS (airbag system) control module detects invalid configuration parameters for Airbag Loop 7.

In the BYD Qin PRO SRS architecture, Loop 7 typically corresponds to the right front seat side airbag or the right rear side curtain module.

During self-diagnosis, the SRS control module detects that the loop's electrical impedance, squib resistance, or configuration coding does not match the calibrated value (typically 2.0-3.0Ω), or the configuration data stored in the module's internal EEPROM is corrupted or missing.

This is a configuration validity fault rather than a simple open or short circuit.

This fault can prevent the corresponding airbag from deploying during a collision, illuminates the airbag warning lamp continuously, and forces the system into fail-safe mode.

The B168B00 fault code on the Seal U indicates the airbag control module has detected invalid configuration parameters or incorrect resistance for Airbag Loop 7 (right front seat side or right rear curtain airbag). This medium severity issue prevents deployment during collisions and illuminates the warning light. Common causes include internal igniter resistance faults or loose connectors under the seat. Visit an authorised dealer for repair. Typical repair cost data is available.
4
Cases Logged
5
Causes
Likely Causes — Seal U
  • 1Abnormal resistance in the internal igniter of the Circuit 7 airbag assembly (seat airbag or curtain airbag) due to aging, moisture ingress, or mismatched model, causing impedance to fall outside the standard 1.6-3.5Ω range.
  • 2Poor contact at the wiring harness connector, especially the yellow SRS connector under the seat (G07 or GJK20 series), where frequent seat movement causes terminal pin back-out, oxidation, or intermittent connections.
  • 3SRS control module software version defect (early versions contain a configuration verification algorithm flaw) or corrupted internal module configuration data caused by power fluctuations (discharged battery, improper jump-starting).
  • 4Incorrect replacement airbag module installed after accident repairs or seat/interior trim removal/installation (e.g., fitting a high-spec model airbag to a low-spec model), or failure to perform correct SRS system configuration (coding).
  • 5Low 12V battery voltage (below 9V) or excessive voltage drop in the power supply circuit prevents the SRS module from correctly reading the loop configuration parameters during initialization.
What To Do
  • 1
    Use the VDS2000/VDS2100 diagnostic tool to read the complete fault codes and freeze frame data. Record vehicle speed, voltage, temperature, and other environmental data from the time of the fault. Confirm the fault is Current rather than History.
  • 2
    Check the SRS system power supply: measure the battery voltage (should be ≥12.4V), verify dashboard fuses F2/3 (SRS power supply) and F2/4 (SRS ignition power supply) are intact, and check that ground points G201 and G301 are tight and free of oxidation.
  • 3
    Refer to the BYD workshop manual wiring diagram to identify the specific airbag component for Circuit 7 (typically the right front seat side airbag on the Qin PRO). Disconnect the battery negative terminal and wait at least 90 seconds. Remove the airbag component. Measure the resistance between the two squib terminals (standard value: 2.0±0.3Ω). Measure the insulation resistance between the terminals and the housing (must be >10MΩ).
  • 4
    Check wiring harness continuity: focus on the yellow SRS connector under the seat (marked GJK20 or G07). Check pins for backout, oxidation, or water ingress. Measure harness resistance between the SRS module and the airbag connector (should be <1Ω). Check CAN-H and CAN-L for shorts to ground.
  • 5
    Check the SRS control module software version against the BYD technical bulletin. If the version is lower than V3.2 (refer to the latest TSB for the exact version), update the software. After the update, perform the "SRS System Configuration" special function and rewrite the vehicle model configuration code (Coding).
  • 6
    If the wiring harness and airbag assembly are normal, replace the SRS control module (select the part number based on vehicle configuration, e.g., 5A-3636100A). After replacement, perform configuration, coding, and system calibration.
  • 7
    Clear the fault code. Use the diagnostic tool to perform the "SRS System Self-test" (Active Test) and verify Circuit 7 status displays "Normal". Conduct a road test simulating bumpy road conditions to confirm the fault does not recur.
Real-World Cases
BYD DTC AI Analysis

Qin Pro DM: Water ingress into the under-seat connector caused a Circuit 7 fault.

✓
A 2019 Qin Pro DM with 32,000 km showed a constant airbag warning light on the instrument panel. The retrieved DTC was B168B00 (Loop 7 invalid configuration). Inspection found damp carpet under the right front seat. Disassembly revealed water stains inside SRS harness connector GJK20. Pins 14 (Loop 7 high) and 15 (Loop 7 low) had green copper corrosion, increasing contact resistance to 5.6 Ω, beyond the SRS module threshold. Repair: cleaned the connector with electronic cleaner, blew it dry, applied conductive protective grease, and replaced the waterproof seal under the seat. Fault cleared.
BYD DTC AI Analysis

Qin Pro petrol: Missing coding after accident repair caused configuration error.

✓
A 2018 Qin PRO petrol had a right front side collision. The shop replaced the right front seat airbag and SRS control module. Afterwards, they pulled DTC B168B00. Diagnosis found the new SRS module was a generic part and had not been written with vehicle configuration. They used the VDS diagnostic tool to enter Special Functions → SRS Configuration, entered the correct configuration code 0x07 (example value) based on the VIN and specification table (high/low spec, with/without side curtain airbags), and executed the coding. The fault code cleared automatically and the system passed self-test.
BYD DTC AI Analysis

SRS module data loss after battery drain

✓
A 2019 Qin PRO DM sat for an extended period, causing the 12V battery to discharge to 8.5V. After a jump-start, the airbag warning light stayed on, and it logged DTC B168B00 along with multiple loop configuration faults. Inspection found that the SRS module failed to initialize during the low-voltage start, resulting in internal configuration data validation errors. Repair steps: Replaced the 12V battery (too deeply discharged to recover). Cleared fault codes with a diagnostic tool – no effect. Performed a power reset on the SRS module by disconnecting its power for over 10 minutes. After reconnecting, ran the "System Configuration" and "Collision Data Clear" procedures. Fault fixed.
BYD DTC AI Analysis

Aftermarket seat heater pad caused abnormal circuit impedance

✓
The owner of a 2018 BYD Qin PRO (petrol) added seat heating at an unauthorised workshop. The tech cut into the SRS loop wiring to connect it, placing extra resistance in parallel with Loop 7. The SRS module measured total loop resistance at 1.2 Ω (below the 1.6 Ω lower limit) and flagged an invalid configuration. Fix: Removed the illegal wiring, repaired the SRS harness with solder and heat shrink tubing, and rerouted the harness back to factory routing. Fault cleared. Warning: Never cut into or modify SRS harness wiring.
Other Seal U Fault Codes
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.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.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.B173712DTC B173712 indicates a short to power in the firing circuit of the right second-row side airbag module in the Supplemental Restraint System (SRS). Specifically, the "right second-row side airbag" typically refers to the side impact airbag located in the right B-pillar or the side of the right seat. The "12" suffix indicates a circuit short to battery positive (B+). This fault causes the following conditions: 1) The airbag may fail to ignite and deploy during a collision, resulting in a loss of side impact protection. 2) In extreme cases, unintended triggering may cause accidental airbag deployment. 3) The SRS control unit detects abnormally high circuit voltage (typically above 4.5V) and enters fault protection mode. This may disable the entire airbag system and continuously illuminate the instrument cluster airbag warning light.
Common problems reported for Seal U →Seal U 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.