Mulitplex Communication System

DIAGNOSIS SYSTEM

1. SYSTEM DESCRIPTION




a. If DTC of ECU communication stop is output, connectors may be disconnected, or communication buses may be open at 2 points. It will not become abnormal with only 1 communication bus open.




b. If 2 communication buses are open at the position as shown in the illustration, DTC of ECU communication stop between those 2 buses is output.

2. MULTIPLEX COMMUNICATION SYSTEM (BEAN)
a. The BEAN communication line is used to control the power window regulator master switch assembly (driver door ECU), the multiplex tilt and telescopic ECU (tilt and telescopic ECU), the multiplex network body ECU No. 2 (body No. 2 ECU), the windshield wiper ECU (wiper ECU), the theft deterrent ECU, the power seat ECU, the outer mirror control ECU assembly (mirror ECU), mayday ECU, and the rain sensor, which are connected to the instrument panel junction block assembly (body ECU). If there is a short-circuit (bus-down) in the line, the communication to the system that has a short-circuit (bus-down) will be disabled and the DTC concerning the system will be output from the instrument panel junction block assembly (body ECU).

3. CHECK COMMUNICATION FUNCTION
a. Check the battery voltage.

Standard voltage: 10 to 14 V

b. Inspect the diagnosis trouble code output.
1. Check a diagnosis trouble code concerning the instrument panel junction block assembly (body ECU) by connecting the intelligent tester to the DLC3 and turning the ignition switch ON.

HINT: The display shows communication error (refer to new diagnosis system and the operations when an error occurred).

2. When the display shows diagnostic trouble codes concerning the ECU unconnected and the communication bus defective, perform the inspection depending on the troubleshooting procedures.

HINT: When another diagnostic trouble code is output, refer to the diagnostic trouble code table and check the applicable section.