Information Bus: Description and Operation

MULTIPLEX COMMUNICATION SYSTEM




The system is comprised of the communication modes of the body ECU, engine control module, theft deterrent ECU, power window master SW, combination meter and A/C control assembly. The body electrical systems are controlled by a serial communication in which each ECU is linked to another via a single communication line. This system is also equipped with a self-diagnosis function.

The table shows the systems under the control of the MPX communication system and related ECUs (Communication nodes).

1. COMMUNICATION OUTLINE
Communication is implemented among the combination meter, A/C control assembly, body ECU, engine control module and theft deterrent ECU, and among the body ECU and power window master SW. Upon receiving signals from applicable switches such as the door lock control switch or door courtesy light switch, each ECU determines the conditions of the switches as well as of the doors, and after converting this information into digital signals, outputs them to other ECUs via serial data communication. The ECU that receives these digital signals determines the conditions of the switches and doors so that it can implement various controls such as to activate a door lock motor. However, if there are no changes in the input signals because no doors were opened and no switches were used within 30 seconds, the body ECU interrupts the communication to save electricity. Following this interruption, any changes in the input signals will cause the communication to resume.
For details please refer to the new car features and repair manuals.

MULTIPLEX COMMUNICATION SYSTEM INCLUDES FOLLOWING SYSTEMS
AUTOMATIC AIR CONDITIONING
- AUTOMATIC LIGHT CONTROL
- BACK DOOR OPENER
- CHARGING
- COMBINATION METER
- CRUISE CONTROL
- DOOR LOCK CONTROL AND WIRELESS DOOR LOCK CONTROL
- ELECTRONICALLY CONTROLLED TRANSMISSION AND A/T INDICATOR
- ENGINE CONTROL
- FRONT WINDOW DEICER
- HEADLIGHT
- INTERIOR LIGHT
- KEY REMINDER AND SEAT BELT WARNING
- LIGHT AUTO TURN OFF
- POWER WINDOW
- REAR WINDOW DEFOGGER AND MIRROR HEATER
- THEFT DETERRENT