Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: No Response from Steering Lock ECU (B2786)

Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual / Power Source & Network / Networking / Lin Communication System / No Response from Steering Lock ECU (B2786)

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.
  • Steering lock ECU (steering lock actuator or upper bracket assembly)
  • Certification ECU (smart key ECU 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.
  • If the certification ECU (smart key ECU assembly) or steering lock ECU (steering lock actuator or upper bracket assembly) is replaced, refer to Registration.

    Click here

  • When using the Techstream with the engine 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 Access(CAN). 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.

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 J41 certification ECU (smart key ECU assembly) connector.

(b) Disconnect the L1 steering lock ECU (steering lock actuator or upper bracket assembly) connector.

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

NOTICE:

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

J41-13 (LIN) - L1-5 (LIN)

Engine switch off

Below 1 Ω

J41-13 (LIN) or L1-5 (LIN) - Body ground

Engine switch off

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

2.

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

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

L1-7 (B) - L1-1 (GND)

Always

11 to 14 V

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

L1-1 (GND) - Body ground

Always

Below 1 Ω
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

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

NEXT

4.

REGISTER ECU CODE REGISTRATION

(a) Register the recognition codes in the ECUs.

HINT:

Refer to Registration.

Click here

NEXT

5.

CHECK FOR DTC

(a) Clear the DTCs.

Click here

Body Electrical > Smart Access > Clear DTCs

(b) Recheck for DTCs.

Body Electrical > Smart Access > Trouble Codes

OK:

DTC B2786 is not output.

OK

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

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

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