AU
B170E11

B170E11 indicates a short to ground in the ignition circuit of the right side curtain airbag — Seal U

Safety System

B170E11 indicates a short to ground in the ignition circuit of the right side curtain airbag.

In the BYD SRS (Supplemental Restraint System) architecture, this fault code indicates the airbag control unit (ACU) detects an abnormally low-resistance path between the right side curtain airbag squib wiring and vehicle body ground (typically below the 1.5-2.0 ohm threshold).

This short circuit causes the ACU to determine the curtain airbag cannot deploy normally, triggering fail-safe mode.

The instrument panel airbag warning light illuminates continuously, and the system suspends deployment control for this curtain airbag.

Consequently, the right side curtain airbag may fail to activate during a side collision, severely compromising crash protection for right-side occupants, particularly head protection.

Potential causes include damaged wiring harness insulation, connector water ingress and corrosion, an internal short circuit in the clock spring, or a squib failure within the curtain airbag module itself.

The B170E11 fault code on the Seal U indicates a short to ground in the right side curtain airbag ignition circuit. This is a high-severity SRS fault because the curtain airbag may not deploy in a side impact. Common causes include damaged wiring in the pillar or roof area, or water ingress and corrosion at the airbag connector. Visit an authorised dealer for diagnosis and repair. Typical repair cost data is available.
3
Cases Logged
5
Causes
Likely Causes — Seal U
  • 1Right curtain airbag wiring harness wear: Loose wiring harness retaining clips inside the A-pillar, B-pillar, or C-pillar trim panels cause the harness to rub against sharp metal body edges over time, damaging the insulation and shorting the wire to ground.
  • 2Connector water ingress and corrosion: An aged sealing ring on the right-side curtain airbag connector (usually located above the B-pillar or roof side rail) allows water entry after heavy rain, car washes, or leaks from a blocked sunroof drain tube. This corrodes the internal terminals, causing a short to ground.
  • 3Clock spring or spiral cable fault: If the right curtain airbag circuit on this model routes through the B-pillar wiring harness spiral cable (clock spring), a broken internal flat cable or abnormal winding can cause the wire core to short to ground.
  • 4Internal fault in the curtain airbag module: The squib inside the curtain airbag assembly internally shorted to ground due to a manufacturing defect, aging, or previous impact.
  • 5SRS ECU monitoring circuit false report: In very rare cases, an internal monitoring circuit fault in the airbag control unit triggers a false short circuit fault.
What To Do
  • 1
    Safety preparation and power isolation: For new energy vehicles, first disconnect the high-voltage service disconnect switch. For all vehicles, disconnect the 12V battery negative terminal and wait at least 90 seconds (3 minutes for some models) to fully discharge the SRS capacitor and prevent accidental airbag deployment.
  • 2
    Visual and physical inspection: Remove the right A-pillar and B-pillar upper trim panels and the roof side trim panel. Inspect the curtain airbag wiring harness for obvious wear, crushing, damage, or signs of water ingress. Focus on the contact points between the wiring harness and the vehicle body metal.
  • 3
    Resistance measurement and fault location: Use a multimeter (do not use the continuity buzzer mode on the airbag circuit) to measure the resistance to ground of the right curtain airbag circuit at the SRS ECU connector. If the resistance is close to 0 ohms, disconnect the intermediate connectors section by section and measure each section to determine if the short circuit is in the ECU-to-connector section, the connector-to-curtain airbag section, or inside the curtain airbag module.
  • 4
    Connector treatment: If the connector has water ingress, thoroughly clean the terminals with electronic contact cleaner, blow them dry with compressed air, apply special conductive grease, replace the waterproof sealing ring, and ensure a secure connection.
  • 5
    Wiring harness repair or replacement: For a damaged wiring harness, cut out the damaged section. Solder or crimp a high-temperature wire of the same specification (usually a yellow wire). Apply double-layer insulation (heat-shrink tubing + electrical tape) and re-secure the wiring harness routing to prevent interference.
  • 6
    Component replacement verification: If confirming an internal short circuit in the curtain airbag module, replace the genuine right curtain airbag assembly. (Note: Handle airbag components with care, avoid dropping them, and ensure correct polarity during installation.)
  • 7
    System reset and road test: Reconnect all components and power supply. Use VDS2000/VDS1000 to clear the fault code. Perform the SRS system self-check (Active Test or self-check procedure). Confirm B170E11 no longer appears and the instrument cluster airbag warning light turns off normally.
Real-World Cases
BYD DTC AI Analysis

Qin Pro: Right curtain airbag wiring harness chafed at A-pillar, short circuit

✓
The airbag warning light on the instrument panel illuminated intermittently. VDS diagnostics retrieved fault code B170E11 (right curtain airbag short to earth). Removed the right A-pillar trim and found the curtain airbag harness retaining clip had come loose. The harness had been rubbing against the A-pillar metal frame edge during driving, wearing through the insulation and allowing the copper core to short directly to earth. Repair: Re-wrapped the damaged harness with high-temperature insulation tape and corrugated tubing, rerouted it to avoid sharp edges, and reinstalled the retaining clips, ensuring clearance exceeded 15 mm. Cleared the fault codes and monitored for one month with no recurrence.
Original source ↗
BYD DTC AI Analysis

E2 Right side curtain airbag connector water ingress corrosion

✓
After a heavy rainstorm, the airbag warning light stayed on constantly. A VDS scan showed DTC B170E11. Inspected the right B-pillar upper curtain airbag connector (white 2-pin) and found clear water stains and green copper corrosion inside, with abnormally low resistance across the terminals. Traced the leak to a detached right rear sunroof drain hose joint, allowing rainwater to seep into the B-pillar. Repair: Cleaned the connector terminal oxides with dedicated electronic contact cleaner. Applied conductive anti-corrosion paste. Replaced the connector seal. Repaired the sunroof drain hose. Performed a water spray test, confirmed no leakage, then reassembled. Fault resolved.
Original source ↗
BYD DTC AI Analysis

Qin EV curtain airbag module internal short circuit after collision repair

✓
After a side-impact collision, an authorised service centre replaced the right curtain airbag and SRS ECU. After delivery, the instrument cluster still displayed an airbag fault. VDS read DTC B170E11. Inspected the wiring harness – no abnormality. Measured resistance of the newly replaced right curtain airbag module and found continuity between both igniter terminals and the housing (ground) – internal short circuit confirmed (likely damaged during transport or storage). Solution: Replaced with another genuine right curtain airbag module. Performed coding and system calibration using VDS. Ran a crash sensor simulation test. Confirmed right curtain circuit resistance within normal range (2.0–3.0 ohms). Cleared DTC; system self-test passed.
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.