2003 Lexus LS 430FACTORY OEM SERVICE PROCEDURE

Multiplex Communication System Operation: Notes

WARNING: This page is about a different car, the 2003 Lexus GS 430, 2003 Lexus GS 300, 2002 Lexus GS 430, and 2002 Lexus GS 300. However, it is still accessible from the selected car via links, so may be relevant.

The system is comprised of the communication nodes of the body ECU No. 1, body ECU No. 2, driver door ECU, front passenger door ECU, rear door LH ECU, rear door RH ECU, engine control module, instrument cluster, A/C control assembly, tilt and telescopic ECU, power seat ECU, moon roof control ECU, center air bag sensor assembly and gateway ECU. 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. To see the systems under the control of the MPX (multiplex communication system) and related ECUs (communication nodes), see Fig 1.

The multiplex communication system includes the following systems:

  • Automatic Air Conditioning.
  • Automatic Light Control.
  • Charging.
  • Cruise Control.
  • Door Lock Control.
  • Electronically Controlled Transmission and A/T Indicator.
  • Engine Control.
  • Headlight.
  • Interior Light.
  • Instrument Cluster.
  • Key Reminder.
  • Light Auto Turn Off.
  • Mirror Heater.
  • Moon Roof.
  • Power Seat (Driver's Seat W/ Driving Position Memory).
  • Power Tilt and Power Telescopic.
  • Power Window.
  • Rear Window Defogger.
  • Remote Control Mirror.
  • Seat Belt Warning.
  • SRS (Supplemental Restraint System).
  • Stop Light.
  • Tail Light.
  • Theft Deterrent.
  • VSC (Vehicle Skid Control).
  • Wireless Door Lock Control.

Fig 1: Identifying Multiplex Communication System
G00184918Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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