B1780 on Lexus
Theft Lock / Anti-Theft System Enabled (manufacturer-specific)
B1780 on Lexus vehicles indicates theft lock / anti-theft system enabled (manufacturer-specific). Au7o has documented this code across 1 Lexus model — most commonly on LX. 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.
Common Causes of B1780
- •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
B1780 on Lexus by Model
Lexus LX(1 issue)
- Front Occupant Classification / Airbag Sensor Fault Triggering SRS Warning and Airbag Recall Repairs2022-2024
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.
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View B1780 across all makes →Frequently Asked Questions
What does B1780 mean on Lexus?▼
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. On Lexus specifically, this code is documented across 1 model.
What causes B1780 on Lexus vehicles?▼
Common causes on Lexus: 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. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix B1780 on a Lexus?▼
Repair costs vary widely depending on the root cause and specific Lexus model.
Which Lexus models have B1780 documented?▼
Au7o has documented B1780 on 1 Lexus model: LX.