Multiplex Communication System: Notes
WARNING: This page is about a different car, the 2003 Lexus IS 300 and 2002 Lexus IS 300. However, it is still accessible from the selected car via links, so may be relevant.
Multiplex communication system includes the following systems:
- Automatic Air Conditioning.
- Automatic Light Control.
- Back Door Opener/Luggage Compartment Door.
- 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.
The system is comprised of the communication modes of the body ECU, engine control module, anti-theft 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 below shows the systems under the control of the MPX and related ECUs (communication modes). See Fig 1.