AU
B169000

DTC B169000 indicates the airbag control unit (SRS ECU) detects an abnormal configuration parameter in Loop 12 — Seal U

Safety System

DTC B169000 indicates the airbag control unit (SRS ECU) detects an abnormal configuration parameter in Loop 12.

In the BYD Qin PRO SRS system, "Loop 12" typically corresponds to the communication/ignition circuit for the left front seat side airbag (or seat occupancy recognition sensor). "Invalid configuration" means the configuration data stored in the ECU does not match the connected hardware.

Causes include circuit resistance outside the standard range (normal: 2.0-3.0 Ω), wiring open or short circuits, or failing to write the configuration after replacing the airbag assembly or control unit.

This fault may prevent the corresponding airbag from deploying properly during a collision or create an unintended deployment risk, classifying it as a functional safety fault.

5
Cases Logged
5
Causes
Likely Causes — Seal U
  • 1Wiring harness under seat worn or broken: Frequent seat adjustment on Qin PRO models repeatedly bends the yellow airbag wiring harness (circuit 12) under the seat frame. This long-term bending breaks the internal copper wires or damages the insulation, causing abnormal resistance.
  • 2SRS control unit configuration data lost: Vehicle power loss (e.g., discharged battery or battery replacement) or a control unit software fault causes verification failure of the stored circuit configuration parameters.
  • 3Seat airbag assembly not programmed after replacement: After replacing the left front seat assembly or side airbag module, failure to perform the 'Airbag Configuration' function using VDS2000 prevents the ECU from recognizing the correct resistance configuration.
  • 4Poor connector contact: Water ingress, oxidation, or vibration increases pin contact resistance at the yellow airbag connector under the seat (usually located at the front of the seat rail).
  • 5Circuit fault caused by modification: Installing seat ventilation/heating or replacing with a non-genuine seat damaged the airbag wiring harness circuit integrity.
What To Do
  • 1
    Diagnostic scan: Use BYD VDS2000/VDS3000 to access the SRS system, read freeze frame data, and verify the Circuit 12 resistance value when the fault occurred (normal: 2.0-3.0 Ω, >6 Ω indicates open circuit, <1 Ω indicates short circuit).
  • 2
    Locate circuit 12 component: Refer to the Qin PRO workshop manual wiring diagram to confirm circuit 12 corresponds to the left front seat side airbag (or seat occupancy sensor on some models). Inspect the component for visible damage.
  • 3
    Check the seat wiring harness: Move the seat to the fully forward and fully rearward positions. Inspect the wiring harness inside the yellow corrugated conduit under the seat for wear. Specifically check if the harness retaining clip near the slide rail mounting point has detached, crushing the wiring harness.
  • 4
    Measure circuit resistance: Disconnect the 12 V battery negative terminal, wait 3 minutes, then unplug the SRS ECU connector. Measure the resistance between the pins of circuit 12. The resistance should be 2.0-3.0 Ω. If abnormal, unplug the connector under the seat and measure in sections to isolate the fault point.
  • 5
    Check connector condition: Inspect the yellow airbag connector under the seat (usually featuring a shorting bar). Verify terminals are free of oxidation, pins are not backed out, and the connector lock is intact. Use the special tool to clean or replace the connector if necessary.
  • 6
    Reconfigure the SRS: If the wiring is normal, use the diagnostic tool to execute the 'Airbag System Configuration' function and rewrite the vehicle VIN and airbag configuration code (obtain the vehicle's original configuration code from the BYD DMS system).
  • 7
    System verification: Clear the fault code, perform an SRS system self-check (ignition switch ON, wait for the indicator lamp to turn off), simulate a collision test (use a dedicated resistor in place of the airbag), and confirm the fault does not recur.
Real-World Cases
BYD DTC AI Analysis

Qin PRO DM seat adjustment causing wiring harness chafing

✓
A 2019 Qin PRO DM with 32,000 km had the airbag warning light on. Scan tool retrieved DTC B169000 - Loop 12 Invalid Configuration; freeze frame data showed 6.8Ω resistance (open circuit). Inspection found the yellow airbag harness under the front left seat rubbing against the seat rail during fore-aft adjustment, wearing through the insulation and fracturing the copper wires. Replaced the harness assembly (Part No.: CJ-6895123-XX), rerouted the wiring and added anti-chafe sleeving, and repositioned the harness clips to avoid contact with the rail. Fault resolved.
BYD DTC AI Analysis

Replaced the seat assembly but did not configure it

✓
2018 BYD Qin Pro (petrol). The airbag warning light came on after a repair shop replaced the left front seat leather. DTC B169000. Data stream showed Loop 12 resistance at 0.5 Ω (too low). Diagnosis found the side airbag had been removed during the seat leather replacement and reinstalled without performing configuration. The Qin Pro seat side airbag uses configurable resistance identification, so the airbag resistance did not match the vehicle’s stored configuration. Used VDS2000 to access ‘Special Functions - Airbag Configuration’, entered the original seat identification resistance code (located on the seat label), and completed configuration. The fault cleared.
BYD DTC AI Analysis

Water ingress caused the connector to oxidise

✓
A 2019 BYD Qin Pro DM came in with the airbag warning light on after rain. DTC B169000 was intermittent. Inspection of the airbag connector beneath the left front seat (yellow two-pin plug) revealed water marks and green corrosion on the terminals, causing erratic contact resistance (fluctuating between normal 2.3Ω and open circuit). Water entered the seat rail area when the vehicle was washed. The technician cleaned the connector pins with electronic cleaner, applied conductive grease, replaced the waterproof seal ring, and cleaned the seat drainage holes. After clearing the fault code, the fault did not recur at the one-week follow-up.
BYD DTC AI Analysis

SRS control unit software fault

✓
A batch of 2018 Qin PRO vehicles exhibited DTC B169000. The airbag warning light suddenly illuminated on several cars while driving, without prior accident repairs. Testing found normal Circuit 12 loop resistance (2.2Ω) on all vehicles, but the ECU continuously flagged a configuration error. Diagnosis: an SRS control unit (ACU) software bug in early production batches, causing false configuration error reports under specific temperature conditions. Upgrading the ACU software to version V3.2 (per BYD Technical Service Bulletin TSB-2019-SRS-03) resolved the issue; the fault did not recur.
BYD DTC AI Analysis

Aftermarket seat ventilation installation damaged the circuit

✓
A 2019 BYD Qin PRO. The airbag light came on the day after the owner had a seat ventilation system installed at an aftermarket shop. DTC B169000 set. Measured infinite resistance on circuit 12. Inspection found the installer accidentally severed the side airbag harness (circuit 12) while drilling into the seat foam. Repair: replaced the damaged harness section, re-soldered the connections and insulated them with double-layer heat shrink tubing, then restored the original harness routing. Do not drill, cut or modify anything within 5cm of airbag components.
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.