B1611 – Front passenger frontal airbag circuit short to ground (BYD)

B1611 means the front passenger airbag circuit has an electrical short to ground, and the most likely real-world effect is an illuminated airbag/SRS warning light with the passenger frontal airbag disabled. That means the restraint system may not protect as designed in a crash. This is a BYD manufacturer-specific code, and the exact monitoring strategy can vary by platform and model year. According to BYD factory diagnostic data, this code indicates a “Front passenger frontal airbag circuit short to ground,” which is a safety-critical fault that must be diagnosed with proper SRS depowering procedures and OEM-approved testing methods before any connectors are handled.

B1611 Quick Answer

B1611 on a BYD indicates the SRS control unit detected the front passenger frontal airbag circuit is shorted to ground. Treat it as a safety fault: depower the SRS before touching any airbag wiring and verify the circuit fault before replacing parts.

What Does B1611 Mean?

Official definition (BYD-specific): “Front passenger frontal airbag circuit short to ground.” In practice, the SRS module has decided the electrical path that commands/monitors the front passenger frontal airbag is grounded when it should not be, so it turns on the SRS warning and typically inhibits that deployment channel to prevent an unintended event.

What the module is actually checking and why it matters: The SRS control unit continuously monitors the passenger frontal airbag loop for electrical integrity. A “short to ground” is set when the module sees the circuit pulled low (grounded) in a way that does not match its expected resistance/continuity pattern for a healthy squib/connector/harness. That distinction matters for diagnosis: this code is not telling you “replace the airbag”—it’s telling you the circuit is electrically grounded somewhere, which is most often a wiring/connector issue, incorrect probing damage, or a failed component in the monitored loop. Confirm the short with OEM-approved methods only; improper testing can deploy an airbag or damage the SRS ECU.

Theory of Operation

Under normal conditions, the BYD SRS control unit (airbag ECU) supervises each deployment loop, including the front passenger frontal airbag, by applying a controlled monitoring signal and evaluating the return characteristics of the circuit. The module expects a very specific electrical “signature” from the airbag igniter (squib), connectors, and harness. If a crash event is detected, the module can command deployment by energizing the appropriate loop(s).

B1611 sets when the passenger frontal airbag loop is no longer electrically isolated as designed and is instead being pulled to ground. This can occur from chafed wiring contacting the body structure, contamination/moisture inside a connector creating a ground path, a damaged connector shorting terminals, or an internal short in a component within that loop. Because the SRS ECU must prevent unintended deployment and cannot trust the loop integrity, it stores the fault and illuminates the warning, often disabling the affected airbag channel until the circuit tests normal again and the fault is properly cleared with an SRS-capable scan tool.

Symptoms

You’ll typically notice one or more of the following when B1611 is present on a BYD:

• Airbag light illuminated (SRS warning lamp on the cluster)
• Passenger airbag status message/indicator showing the front passenger airbag is unavailable or faulted (wording varies by BYD platform)
• DTC storage B1611 stored in SRS/Body fault memory and returning immediately after a proper clear if the short remains
• Safety function inhibited passenger frontal airbag deployment channel disabled or suppressed by the SRS ECU as a protective strategy
• Intermittent behavior warning light that changes with seat position movement or cabin temperature/humidity if a connector/harness is marginal
• Additional SRS codes related airbag circuit or passenger-side restraint faults present if the short affects shared routing/connectors

Common Causes

• Harness chafed to body ground: The passenger frontal airbag squib wires can rub through insulation near brackets, seat/console edges, or dash structure, allowing one or both conductors to contact ground and be interpreted by the SRS ECU as a short to ground.
• Connector terminal shorting from deformation or misalignment: A partially latched or damaged SRS connector (CPA/lock not fully engaged) can push terminals out of position so the squib circuit touches ground through the connector shell or adjacent grounded hardware.
• Moisture intrusion/corrosion at SRS connectors: Water entry from HVAC condensation, windshield leaks, or wet detailing can create conductive paths and corrosion products that effectively pull the circuit toward ground and trigger the short-to-ground fault logic.
• Pinched harness after interior/SRS-related work: Dash, glovebox, infotainment, or HVAC service can trap the airbag harness between panels or fasteners, damaging insulation and producing an intermittent or hard short to ground.
• Improper aftermarket accessory installation: Screws, zip ties, or accessory wiring routed near the passenger airbag harness may pierce insulation or clamp the loom against grounded metal, creating a short-to-ground condition.
• Faulty passenger frontal airbag module (squib internal short to case/ground): If the inflator/squib assembly internally fails, the SRS ECU may see the circuit pulled to ground even with an intact harness, though this must be proven with approved test methods before replacement.
• Damage at the SRS ECU/center harness junction: Impact, previous repair, or connector strain near the SRS ECU can compromise terminal tension or insulation, allowing the passenger airbag circuit to contact ground on the ECU side of the harness.
• Non-approved testing/backprobing damage: Probing SRS connectors with standard meter leads can spread terminals or breach seals, later causing unintended contact to ground and repeat B1611 on BYD platforms.

Diagnosis Steps

Tools needed: a scan tool with full BYD SRS access (capable of reading DTC details, event data, and live parameters), a quality DVOM for power/ground checks (never on airbag squib circuits directly), wiring diagrams/service info for the 2020 Dolphin, and OEM-approved SRS test adapters/shorting bars as specified by BYD. Follow SRS depowering and wait-time procedures before touching any SRS connector.

1. Confirm the DTC and capture evidence: Perform a complete SRS scan, confirm B1611 is present, and record DTC status, stored/active state, and any associated codes (battery low, ignition feed, other squib codes). Save freeze frame/event data and note when it sets (key-on, during driving, after bumps), because that pattern guides harness vs. component suspicion.
2. Do a visual inspection of the full circuit path before any meter work: With the vehicle made safe (ignition OFF; follow BYD SRS depower procedure and required wait time), visually trace the passenger frontal airbag circuit routing as far as accessible: behind glovebox/dash areas, along harness channels, at intermediate connectors, and at the SRS ECU area. Look specifically for pinched loom, shiny rub spots, crushed conduit, wetness, aftermarket fasteners, or evidence of prior interior work.
3. Check fuses and power distribution first: Still staying out of squib connectors, verify SRS-related fuse(s) and ignition feed(s) are correct for the restraint system and that no fuse holder heat damage or loose fit exists. A power feed issue won’t “cause” a short-to-ground, but low system voltage and unstable feeds can produce misleading SRS faults and must be corrected before deeper circuit isolation.
4. Verify SRS ECU power and ground integrity under load: Using service information for correct terminals, perform loaded voltage-drop checks on the SRS ECU main ground(s) and B+ / ignition feed(s). Do not pierce insulation in SRS harnesses; use approved breakout methods at non-squib power/ground circuits. Poor grounds can distort the ECU’s internal monitoring and complicate diagnosis of a “short to ground” callout.
5. Make the system safe and access connectors correctly: Depower SRS again before disconnecting any SRS connectors. Disconnect the passenger frontal airbag connector and the corresponding SRS ECU connector path only as directed by BYD service information. Use correct handling: no static discharge, no impacts, no test light, no resistance measurements across an airbag module, and no probing of connector faces with standard meter leads.
6. Inspect terminals and connector locks in detail: Examine connector housings for broken secondary locks/CPA, bent terminals, pushed-out pins, poor terminal tension indications, contamination, or water tracks. On BYD vehicles, connector security is critical—an incompletely seated lock can allow terminal movement that intermittently grounds the circuit. Correct any mechanical issues before electrical isolation tests.
7. Isolate the harness from the airbag module and check for a ground fault on the vehicle side: With the airbag module disconnected and SRS ECU-side disconnected as required, use OEM-approved test adapters to check whether either squib conductor shows continuity to chassis ground on the harness side. Do not measure through the airbag module. If a conductor is grounded, the short-to-ground is in the harness/connector path; locate it by sectional isolation (disconnect intermediate connectors and re-check to narrow the segment).
8. Wiggle-test to reproduce intermittents (without reconnecting squib components): If the short is intermittent, keep the airbag module disconnected and safely manipulate the harness along suspected rub points (near brackets, edges, and recent work areas). Monitor the ground-fault indication with your meter at the isolated harness test point. A change during movement confirms a harness/connector issue rather than the module.
9. Prove whether the airbag module is the source only after the harness is cleared: If the harness side shows no short to ground and connectors are verified, follow BYD-approved methods to evaluate the passenger frontal airbag module side (typically via specified simulator/test load procedure using OEM tools, not a DVOM across the inflator). If the fault logic points to a grounded condition only when the module is included in the circuit, the module may be at fault—confirm using service procedures before replacement authorization.
10. Repair the verified defect and restore harness protection: Repair chafed wiring with OEM-approved methods for SRS circuits (correct gauge, sealing, strain relief, and re-wrapping/looming). Re-route away from sharp edges, replace damaged retainers/clips, and ensure grommets and protective sleeving are restored. Replace any connector/terminal that fails retention or shows corrosion; do not “tighten” terminals by improvisation.
11. Reassemble, repower, and confirm the repair: Reconnect all SRS connectors with locks fully engaged, reassemble interior trim ensuring no harness pinch points, then repower following BYD procedure. Perform a full SRS scan to confirm B1611 is cleared by normal verification logic and does not return. Confirm the SRS warning indicator performs the correct bulb check and goes out, and recheck for pending/history codes.

Professional tip: Treat “short to ground” on a frontal airbag circuit as a physical wiring/connector problem until proven otherwise. On the BYD Dolphin, the fastest path to an accurate diagnosis is isolating the squib circuit into sections and proving where the ground appears—never ohm-check the inflator, never use a test light on SRS wiring, and never defeat connector shorting features. Most repeat comebacks come from incomplete connector locking or missed harness rub points after trim reinstallation.

Possible Fixes

• Repair or replace the damaged harness section: Correct a proven short-to-ground by restoring insulation integrity, conductor routing, and protective loom in the identified segment of the passenger frontal airbag circuit.
• Replace/repair affected connector housing and terminals: If terminal damage, corrosion, poor pin fit, or broken secondary locks are confirmed, replace the connector/terminals using OEM-approved parts and crimping methods.
• Correct harness routing and retention: Re-route away from brackets/edges, reinstall missing clips, add specified abrasion protection, and eliminate pinch points created during previous dash or glovebox service.
• Remove or rework aftermarket accessory interference: Relocate accessory wiring, remove intrusive fasteners, and restore the SRS harness to factory routing if an accessory installation caused the short.
• Replace the passenger frontal airbag module only after circuit proof: If the harness and connectors test clean and BYD-approved simulator/testing confirms the module pulls the circuit to ground, replace the passenger frontal airbag module and verify no related SRS codes remain.
• Address confirmed moisture entry: Dry and clean affected areas, repair the water leak source, and replace corroded terminals/connectors to prevent recurrence of a conductive path to ground.

Can I Still Drive With B1611?

You can usually drive a BYD Dolphin with DTC B1611 stored because it is an SRS (airbag) circuit fault rather than a propulsion or braking fault. However, you must treat the vehicle as having a potentially compromised restraint system. With “front passenger frontal airbag circuit short to ground,” the SRS control unit may disable that airbag channel and may also inhibit other SRS functions depending on BYD’s internal fault strategy. Do not allow a passenger to rely on that airbag. Do not attempt DIY electrical testing at the airbag connectors; incorrect probing can deploy an airbag or damage the SRS ECU. If the SRS warning lamp is on, schedule immediate diagnosis using SRS-approved methods and proper depowering procedures.

How Serious Is This Code?

B1611 is serious because it points to a squib circuit integrity problem on the front passenger frontal airbag: a “short to ground” is an electrical failure mode that prevents controlled deployment when commanded and can trigger SRS disablement to prevent unintended deployment. It is mostly an inconvenience only in the narrow sense that the car will often still drive normally; it is a safety issue because crash protection may be reduced. On BYD vehicles, manufacturer-specific SRS codes can also be latched and require correct repair verification and scan-tool confirmation to restore readiness. Diagnosis requires SRS-certified equipment, technician training, and OEM-approved test methods (no standard multimeter probing of squib circuits).

Common Misdiagnoses

The most common mistake with B1611 on BYD is replacing the passenger airbag module (or worse, the SRS ECU) before proving the circuit is actually shorted to ground. Shops also misdiagnose by checking resistance directly across airbag terminals with a standard meter or piercing probes, which is unsafe and can set additional faults. Another frequent error is ignoring harness routing: a short-to-ground often comes from rubbed-through wiring under the dash, at the glovebox area, or near brackets, not from the airbag itself. Finally, technicians sometimes clear codes or cycle the ignition repeatedly instead of performing proper depowering, connector inspection, and controlled circuit checks with an approved load tool or simulator.

Most Likely Fix

The most frequently confirmed repair direction for B1611 is correcting a wiring/connector fault in the front passenger frontal airbag circuit that is allowing the squib line to contact ground—typically damaged insulation, pinched harness, moisture/contamination at a connector, or a partially backed-out terminal. A secondary, but less common, direction is a fault internal to the passenger airbag module or the clockspring/connector interface depending on BYD’s circuit layout. Neither should be replaced until the short-to-ground is verified with SRS-approved test equipment, the vehicle is properly depowered, and the harness is isolated segment-by-segment to locate where the ground path is occurring.

Repair Costs

SRS/airbag repair costs vary significantly by component. Diagnosis must be performed by a qualified technician with SRS-capable equipment. Do not attempt airbag system repairs without proper training and safety procedures.

Last updated: March 29, 2026