Toyota 4Runner: System Description

Toyota 4Runner Service Manual / Power Source / Network / Networking / Lin Communication System / System Description

SYSTEM DESCRIPTION

1. LIN COMMUNICATION SYSTEM DESCRIPTION

The LIN communication system is used for communication between the components in the tables below. If communication cannot be performed through LIN communication because of a break in the communication lines or some other reason, the master control ECU of the relevant system stores DTCs. Refer to the table below about the communication bus lines and connected components.

HINT:

Each component has a fail-safe function which activates to maintain the minimum performance of the system and protect the system.
In the following table, "○" indicates that the function applies, and "-" indicates that it does not.

Door Bus Lines

Component	Master Control	LIN Communication DTC Output Function
Main body ECU (multiplex network body ECU)	○	○
Multiplex network master switch assembly	-	-
Front power window regulator motor assembly LH	-	-
Front power window regulator motor assembly RH	-	-
Rear power window regulator motor assembly LH	-	-
Rear power window regulator motor assembly RH	-	-
Sliding roof ECU (sliding roof drive gear sub-assembly)*	-	-
Multiplex network door ECU (back door P/W)	-	-

*: w/ Sliding Roof System

Certification Bus Lines (w/ Smart Key System)

Component	Master Control	LIN Communication DTC Output Function
Certification ECU (smart key ECU assembly)	○	○
Power management control ECU	-	○
Steering lock ECU (steering lock actuator assembly)	-	-
ID code box (immobilizer code ECU)	-	-

Air Conditioning Bus Lines

Component	Master Control	LIN Communication DTC Output Function
Air conditioning amplifier assembly	○	-
Heater control assembly	-	-

Sub-LIN Bus Lines

Component	Master Control	LIN Communication DTC Output Function
Multiplex network door ECU (back door P/W)	○	○
Back door power window regulator sub-assembly	-	-

Drive Monitor Switch Bus Lines (w/ CRAWL Control)

Component	Master Control	LIN Communication DTC Output Function
Drive monitor switch	○	○
Combination meter assembly	-	-

System Diagram

SYSTEM DIAGRAM 1. DOOR BUS LINES 2. CERTIFICATION BUS LINES (w/ Smart Key System) 3. AIR CONDITIONING BUS LINES 4. SUB-LIN BUS LINES 5. DRIVE MONITOR SWITCH BUS LINES (w/ CRAWL Control) ...

How To Proceed With Troubleshooting

CAUTION / NOTICE / HINT HINT: Use these procedures to troubleshoot the LIN communication system. *: Use the Techstream. PROCEDURE 1. VEHICLE BROUGHT TO ...

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