NETWORKING: LIN COMMUNICATION SYSTEM: B1206; P/W Master Switch Communication Stop; 2016 - 2020 MY Sienna [12/2015

Last Modified: 04-05-2023	6.11:8.1.0	Doc ID: RM100000000VJEU
Model Year Start: 2016	Model: Sienna	Prod Date Range: [12/2015 - ]
Title: NETWORKING: LIN COMMUNICATION SYSTEM: B1206; P/W Master Switch Communication Stop; 2016 - 2020 MY Sienna [12/2015 - ]

DTC

B1206

P/W Master Switch Communication Stop

DESCRIPTION

This DTC is stored when LIN communication between the multiplex network master switch assembly and main body ECU stops for 10 seconds or more.

DTC Code	DTC Detection Condition	Trouble Area
B1206	No communication between the multiplex network master switch assembly and main body ECU for 10 seconds or more.	Multiplex network master switch assembly Main body ECU Harness or connector Instrument panel junction block assembly

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 switch on and off at 1.5 second intervals until communication between the Techstream and vehicle begins.
Inspect the fuses for circuits related to this system before performing the following inspection procedure.

HINT:

DTC B2325 is stored when the communication between the multiplex network master switch assembly and main body ECU stops.

PROCEDURE

CLEAR DTC

(a) Clear the DTC (See page ).

2.	CHECK FOR DTC

(a) Check for DTCs (See page ).

Result

Result	Proceed to
DTC B1206 is output	A
DTC B1206 and B2325 are output	B

HINT:

When both B1206 and B2325 are output at the same time, troubleshoot B2325 first.

GO TO DIAGNOSTIC TROUBLE CODE CHART

(See page )

3.	INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

Text in Illustration

Component without harness connected

(Instrument Panel Junction Block Assembly)

(a) Remove the Instrument Panel junction block Assembly (See page ).

(b) Remove the main body ECU from the Instrument Panel junction block Assembly (See page ).

Standard Resistance:

Tester Connection	Condition	Specified Condition
2D-18 - 2I-16 (LIN2)	Always	Below 1 Ω

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

4.	CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - MULTIPLEX NETWORK MASTER SWITCH ASSEMBLY)

(a) Disconnect the 2D instrument panel junction block assembly connector.

(b) Disconnect the H14 multiplex network master switch assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
2D-18 - H14-17 (LIN1)	Always	Below 1 Ω
2D-18 or H14-17 (LIN1) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.	CHECK HARNESS AND CONNECTOR (MULTIPLEX NETWORK MASTER SWITCH ASSEMBLY - BATTERY AND BODY GROUND)

(a) Disconnect the multiplex network master switch assembly connector.

(b) Measure the resistance and voltage according to the value(s) in the tables below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
H14-12 (GND) - Body ground	Always	Below 1 Ω

Standard Voltage:

Tester Connection	Condition	Specified Condition
H14-11 (B) - Body ground	Always	11 to 14 V

Text in Illustration

*a	Front view of wire harness connector (to Multiplex Network Master Switch Assembly)

REPAIR OR REPLACE HARNESS OR CONNECTOR

6.	REPLACE MULTIPLEX NETWORK MASTER SWITCH ASSEMBLY

(a) Replace the multiplex network master switch assembly (See page ).

CLEAR DTC

(a) Clear the DTC (See page ).

8.	CHECK FOR DTC

(a) Recheck for DTCs (See page ).

Result

Result	Proceed to
DTC B1206 is not output	A
DTC B1206 is output	B

END (MULTIPLEX NETWORK MASTER SWITCH ASSEMBLY WAS DEFECTIVE)

REPLACE MAIN BODY ECU