Toyota 4Runner: Back Door ECU Communication Stop (B1287)

Toyota 4Runner Service Manual / Power Source / Network / Networking / Lin Communication System / Back Door ECU Communication Stop (B1287)

DESCRIPTION

This DTC is stored when LIN communication between the multiplex network door ECU (back door P/W) and main body ECU (multiplex network body ECU) stops for 10 seconds or more.

DTC Code	DTC Detection Condition	Trouble Area
B1287	No communication between the multiplex network door ECU (back door P/W) and main body ECU (multiplex network body ECU) for 10 seconds or more.	Multiplex network door ECU (back door P/W) Main body ECU (multiplex network body ECU) Harness or connector

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

When using the Techstream with the ignition switch off to troubleshoot:
Connect the Techstream to the vehicle and turn a courtesy light switch on and off at 1.5 second intervals until communication between the Techstream and vehicle begins.
Inspect the fuses and bulbs for circuits related to this system before performing the following inspection procedure.

HINT:

When communication between the multiplex network door ECU (back door P/W) and main body ECU (multiplex network body ECU) stops, DTC B2325 is also stored.

PROCEDURE

CLEAR DTC

(a) Clear the DTCs (See page ).

2.	CHECK FOR DTC

(a) Check for DTCs (See page ).

OK:

DTC B1287 is not output.

USE SIMULATION METHOD TO CHECK

3.	CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - MULTIPLEX NETWORK DOOR ECU)

(a) Remove the main body ECU (multiplex network body ECU) from the driver side junction block assembly (See page ).

(b) Disconnect the V2 multiplex network door ECU (back door P/W) connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A-16 (LIN2) - V2-16 (MPX1)	Always	Below 1 Ω
A-16 (LIN2) or V2-16 (MPX1) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

4.	CHECK HARNESS AND CONNECTOR (MULTIPLEX NETWORK DOOR ECU - BATTERY AND BODY GROUND)

(a) Disconnect the V2 multiplex network door ECU (back door P/W) connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
V2-6 (GND) - Body ground	Always	Below 1 Ω

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
V2-1 (BDR) - Body ground	Always	11 to 14 V
V2-7 (BECU) - Body ground	Always	11 to 14 V
V2-8 (SIG) - Body ground	Ignition switch ON	11 to 14 V

Text in Illustration

*a	Rear view of wire harness connector (to Multiplex Network Door ECU [Back Door P/W])

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.	REPLACE MULTIPLEX NETWORK DOOR ECU

(a) Temporarily replace the multiplex network door ECU (back door P/W) with a new or normally functioning one (See page ).

CLEAR DTC

(a) Clear the DTCs (See page ).

7.	CHECK FOR DTC

(a) Check for DTCs (See page ).

OK:

DTC B1287 is not output.

END (MULTIPLEX NETWORK DOOR ECU IS DEFECTIVE)

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

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DESCRIPTION The main body ECU (multiplex network body ECU) intermittently monitors the LIN communication bus between the components related to the doors and sliding roof ECU (sliding roof drive g ...

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