Body Electronics Area Network (Bean)

WARNING: This page is about a different car, the 2003 Lexus ES 300 and 2002 Lexus ES 300. However, it is still accessible from the selected car via links, so may be relevant.

The BEAN consists of 2 different systems: One system is a loop-shaped circuit where the driver door ECU and front passenger door ECU are united with the body ECU in the center of the line. Since the line for both front door ECUs is loop-shaped, the communication can be kept by the line that is not open even if a part of the line becomes open for some reason. In case the line becomes shorted to ground or shorted to power for some reason, communication between the body ECU and the front door ECUs will be impossible and DTCs B1214 or B1215 will be output.

The second is a system where the body ECU and theft deterrent ECU are connected alone through a single communication line. In case the line becomes shorted to ground or shorted to power for some reason, communication between the body ECU and the theft deterrent ECU will not be impossible. DTC B1269 is output if communication between the body ECU and theft deterrent ECU is lost.

Diagnostic trouble codes are output if a fault is detected in the communication circuit between the body ECU and driver door ECU, front passenger door ECU and/or theft deterrent ECU.