DTC B2799-86: Engine Immobiliser System Signal (Some Circuit Quantity, Reported via Serial Data) Invalid [08/2020 - ]: Description

WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 2024 Lexus ES 350, 2024 Lexus ES 250, 2023 Lexus ES 350, 2023 Lexus ES 250, and 2022 Lexus ES 350. However, it is still accessible from the selected car via links, so may be relevant.

If there is a communication malfunction between the ECM and ID code box (immobiliser code ECU), or when the communication ID codes do not match, the ECM stores this DTC.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Note
B279986	Engine Immobiliser System Signal (Some Circuit Quantity, Reported via Serial Data) Invalid	Either of the following conditions is met (1 trip detection logic*): A malfunction is detected in the communication or communication lines between the ECM and ID code box (immobiliser code ECU). The communication ID codes of the ECM and ID code box (immobiliser code ECU) do not match.	ID code box (immobiliser code ECU) ECM Wire harness or connector	DTC output confirmation operation (Perform either of the following): Start the engine and wait for 10 seconds. If there is a malfunction, the engine will stop (communication begins within 3 seconds of the engine start operation being performed, and DTCs are stored after 6 seconds). Connect the cable to the negative (-) battery terminal, start the engine and wait for 10 seconds (communication begins within 3 seconds of the engine switch being turned on (IG), and DTCs are stored after 6 seconds).

*: Only output while a malfunction is present.

VEHICLE CONDITION AND FAIL-SAFE OPERATION WHEN MALFUNCTION DETECTED

Vehicle Condition when Malfunction Detected	Fail-safe Operation when Malfunction Detected
Engine cannot be started	-

RELATED DATA LIST AND ACTIVE TEST

DTC No.	Data List and Active Test
B279986	-