NETWORKING: LIN COMMUNICATION SYSTEM (except TMC Made): B2786; No Response from Steering Lock ECU; 2023 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2022

Last Modified: 07-31-2024	6.11:8.1.0	Doc ID: RM1000000026D5Z
Model Year Start: 2023	Model: GR Corolla	Prod Date Range: [09/2022 - 11/2022]
Title: NETWORKING: LIN COMMUNICATION SYSTEM (except TMC Made): B2786; No Response from Steering Lock ECU; 2023 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2022 - 11/2022]

DTC

B2786

No Response from Steering Lock ECU

DESCRIPTION

This DTC is stored when LIN communication between the certification ECU (smart key ECU assembly) and steering lock ECU (steering lock actuator or upper bracket assembly) stops for 10 seconds or more.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
B2786	No Response from Steering Lock ECU	No communication between steering lock ECU (steering lock actuator or upper bracket assembly) and certification ECU (smart key ECU assembly) for 10 seconds or more.	Certification ECU (smart key ECU assembly) Steering lock ECU (steering lock actuator or upper bracket assembly) Wire harness or connector STRG LOCK fuse

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Inspect the fuses for circuits related to this system before performing the following procedure.
When using the Techstream with the power switch off, connect the Techstream to the DLC3 and turn a courtesy light switch on and off at intervals of 1.5 seconds or less until communication between the Techstream and the vehicle begins. Then select Model Code "KEY REGIST" under manual mode and enter the following menus: Body Electrical / Smart Key. While using the Techstream, periodically turn a courtesy light switch on and off at intervals of 1.5 seconds or less to maintain communication between the Techstream and the vehicle.
Before replacing the certification ECU (smart key ECU assembly) or steering lock ECU (steering lock actuator or upper bracket assembly), refer to Registration.
Click here

PROCEDURE

1.	CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY))

(a) Disconnect the I1 certification ECU (smart key ECU assembly) connector.

(b) Disconnect the I59 steering lock ECU (steering lock actuator or upper bracket assembly) connector.

NOTICE:

Make sure that each ECU is in sleep mode before performing the inspection. To enter sleep mode, turn the power switch from on (IG) to off and wait for 180 seconds or more without operating any switches.

Standard Resistance:

Tester Connection	Condition	Specified Condition
I1-14 (LIN) - I59-5 (LIN)	Power switch off	Below 1 Ω
I1-14 (LIN) or I59-5 (LIN) - Body ground	Power switch off	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

2.	CHECK HARNESS AND CONNECTOR (STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY) - AUXILIARY BATTERY, BODY GROUND)

(a) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection	Condition	Specified Condition
I59-7 (B) - I59-1 (GND)	Power switch off	11 to 14 V

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
I59-1 (GND) - Body ground	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

3.	REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY)

(a) Replace the steering lock ECU (steering lock actuator or upper bracket assembly).

Click here

4.	REGISTER ECU CODE REGISTRATION

(a) Register the recognition codes in the ECUs.

Click here

5.	CHECK FOR DTC

(a) Clear the DTCs.

Body Electrical > Smart Key > Clear DTCs

(b) Recheck for DTCs.

Body Electrical > Smart Key > Trouble Codes

OK:

DTC B2786 is not output.

END (STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY) WAS DEFECTIVE)

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)