Code Definition

B2796 — No communication with Immobiliser system

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

About B2796

B2796 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 B2796 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 ECM and the transponder key ECU exchange authentication data over a dedicated communication line each time the engine is started, forming the core of the Lexus immobiliser system. DTC B2796 is set when the ECM receives no communication, or invalid communication, from the immobiliser system, so it cannot confirm that an authorised key is present. Because the ECM will not enable fuel and ignition without a valid immobiliser handshake, loss of this communication leaves the vehicle immobilised. When this code is set the engine typically cranks but does not start and the security indicator flas...

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