Code Definition

B2799 — Engine Immobiliser System Malfunction

System: Body  |  Type: Generic (OBD-II Standard)  |  Make: Lexus

About B2799

B2799 is a generic (obd-ii standard) body diagnostic trouble code recorded for Lexus vehicles. It belongs to the B-prefix family of codes, which covers body, interior, airbag, or comfort-electronics faults.

Scanning & clearing: Body (B) codes are often stored in the body control module, airbag module, or climate module. A basic OBD-II tool usually will not read body codes — an enhanced or OEM-level scan tool is typically required.

Because B2799 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

The Certification (Smart Key) ECU and Engine Immobiliser system monitor key authentication, transponder communication, and immobiliser authorisation status during ignition ON and engine start requests. DTC B2799 is stored when the system determines that immobiliser authentication has failed or that valid confirmation between the transponder key, immobiliser ECU, and engine ECU cannot be achieved within the specified time. This fault is typically set when the engine start is inhibited due to an unrecognised key, invalid immobiliser signal, or internal immobiliser system malfunction.

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