Circuit Description

WARNING: This page is about a different car, the 2003 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.

This DTC is output when the ECM detects errors in the communication between the Transponder Key ECU and the EGM and the in the communication lines.

This DTC is also output when the engine start is attempted with the COMMUNICATION ID between the Transponder key ECU and the ECM is different.

Before troubleshooting for this DTC, make sure that there is no DTC detected in the Transponder Key EC If there is Key code-related DTC (B279X) detected in the Transponder Key ECU, repair it first.

DTC CONDITION DETECTION CHART

DTC No.	Detection Item	Trouble Area
B2799	Error in communication between ECM and Transponder Key ECU, and in communication line. COMMUNICATION ID is different in communication with Transponder Key ECU	Wire harness Transponder Key ECU ECM