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B1780ModerateBody

B1780 on 2022-2024 Lexus LX — Theft Lock / Anti-Theft System Enabled (manufacturer-specific)

1 vehicles · 1 makes

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How to diagnose and fix B1780: most-reported vehicles

Ranked by owner reports. Each card gives the symptoms, how to confirm the cause, the fix, parts and sources for that vehicle.

Lexus LX · 2022–2024

Link to this issueError Codes:B1650B1780B1795

Multiple 2022-2024 Lexus LX owners reported persistent SRS/airbag warning messages and dealer diagnoses related to the front passenger occupant classification system and related airbag components. This generation shares Toyota/Lexus safety-system campaigns affecting front seat occupant sensing and airbag readiness, and owners describe warning lights, repeated dealer visits, and concerns about whether the passenger airbag will deploy correctly. Because the issue directly affects restraint-system operation, it is considered high severity even when the repair itself is covered by recall or warranty.

Common Symptoms

  • SRS warning light illuminated
  • Airbag system malfunction message
  • Passenger airbag OFF/ON status behaving abnormally
  • Warning appears after moving front passenger seat
  • Repeated dealer visits for airbag-related faults

How to Fix

Scan the SRS system with a Toyota/Lexus-capable diagnostic tool and inspect the passenger seat weight/occupant classification components, seat harnesses, and any applicable recall campaign status by VIN. Dealers typically perform recall remedies, recalibration, or replacement of affected seat sensor/airbag-related parts, then clear codes and verify the occupant detection status with a seat calibration procedure. If the warning returns, wiring under the seat and connector tension should be checked carefully.

Typical repair cost:$0 - $2,500

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Lexus · 1 issue

B1780 code reference

General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.

Frequently asked questions

What does B1780 mean?

B1780 stands for "Theft Lock / Anti-Theft System Enabled (manufacturer-specific)." B1780 is a manufacturer-specific body code; on General Motors vehicles it is commonly listed as the anti-theft (Theft Lock) system being enabled, meaning the immobilizer/security function has activated and may be inhibiting normal operation. It indicates a security/anti-theft state or fault rather than a mechanical failure. Depending on the make and circumstances it can be informational or can be associated with a crank/no-start condition. Confirm the exact definition for the specific vehicle.

What are the most common causes of B1780?

The most common causes of B1780 are: Anti-theft system triggered or not yet relearned, Unrecognized or unprogrammed key/transponder, Faulty ignition lock cylinder or anti-theft sensor, Wiring or connector fault in the security circuit, Discharged or weak battery during start, Faulty body control or anti-theft module. The specific cause varies by vehicle.

How much does it cost to fix B1780?

Repair costs vary widely depending on the root cause and vehicle.

Which vehicles are affected by B1780?

Au7o has documented B1780 across 1 vehicle models from 1 manufacturers: Lexus.

Related codes

  • 01367 · Central Locking Pump Run Time Exceeded (Likely Leak)
  • B0081 · First Row Center Seatbelt Load Limiter Deployment Control (Subfault)
  • B0083 · Left Front Impact Sensor Circuit
  • B0092 · Left Side Restraints Sensor 2 (Subfault)
  • B0098 · Right Side Restraints Sensor 3 (Subfault)
  • B00A0 · Occupant Classification System (Subfault)
  • B0229 · Manufacturer-Specific Body Code (GM: Air Recirculation Door Position Feedback Circuit Actuator Range/Performance)
  • B0408 · Temperature Control (Air Mix) Circuit Malfunction
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.

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