Toyota Avalon (XX50) 2019-2022 Service & Repair Manual: GSW Terminal Circuit Malfunction (B1243)

DESCRIPTION

If the collision door lock release function does not operate normally, or an open or short in the GSW input circuit of the main body ECU (multiplex network body ECU) is detected, DTC B1243 will be stored.

HINT:

If DTC B1243 is stored, the automatic door lock function, and collision door lock release function will be prohibited.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

• After turning the engine switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.

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• Before replacing the main body ECU (multiplex network body ECU), refer to Registration.

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PROCEDURE

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Main Body / Trouble Codes.

(e) Clear the DTCs.

(f) Recheck for DTCs.

OK:

DTC B1243 is not output.

OK

USE SIMULATION METHOD TO CHECK

NG

(a) Disconnect the cable from the negative (-) battery terminal.

CAUTION:

Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

NOTICE:

Turning the engine switch on (IG) with the airbag ECU assembly connector disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

(b) Disconnect the G50 airbag ECU assembly connector.

(c) Connect the cable to the negative (-) battery terminal.

(d) Measure the voltage according to the value(s) in the table below. Standard Voltage: Tester Connection Condition Specified Condition G50-25 (GSW) - Body ground Engine switch on (IG) 4.3 to 5.5 V

*a Front view of wire harness connector (to Airbag ECU Assembly)

NG

GO TO STEP 5

OK

(a) Disconnect the cable from the negative (-) battery terminal.

CAUTION:

Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

(b) Replace the airbag ECU assembly.

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NEXT

(a) Clear the DTCs.

(b) Recheck for DTCs.

OK:

DTC B1243 is not output.

OK

END (AIRBAG ECU ASSEMBLY WAS DEFECTIVE)

NG

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

(a) Disconnect the cable from the negative (-) battery terminal.

CAUTION:

Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

(b) Disconnect the 4A instrument panel junction block assembly connector.

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

Standard Resistance:

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

(a) Remove the instrument panel junction block assembly.

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(b) Remove the main body ECU (multiplex network body ECU).

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

Standard Resistance:

OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY