Toyota CH-R Service Manual: No Response from Steering Lock ECU (B2786)

Toyota CH-R Service Manual / 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.
  • When using the Techstream with the ignition 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 the vehicle type 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.
  • 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

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 F1 certification ECU (smart key ECU assembly) connector.

(b) Disconnect the F78 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 ignition switch from ON to off and wait for 180 seconds or more without operating any switches.

Standard Resistance:

Tester Connection

Switch Condition

Specified Condition

F1-13 (LIN) - F78-5 (LIN)

Ignition switch off

Below 1 Ω

F1-13 (LIN) or F78-5 (LIN) - Body ground

Ignition 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

F78-7 (B) - F78-1 (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

F78-1 (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 Key > Clear DTCs

(b) Recheck for DTCs.

Body Electrical > Smart Key > 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)

    Diagnostic Trouble Code Chart
    DIAGNOSTIC TROUBLE CODE CHART LIN Communication System DTC No. Detection Item Link B1206 P/W Master Switch Communication Stop ...

    No Response from ID BOX (B2789)
    DESCRIPTION This DTC is stored when LIN communication between the certification ECU (smart key ECU assembly) and ID code box (immobiliser code ECU) stops for 10 seconds or more. DTC N ...

    Other materials:

    Toyota CH-R Service Manual > Lighting System: Back Door Courtesy Switch Circuit
    DESCRIPTION The main body ECU (Multiplex Network Body ECU) receives a back door open/closed signal from back door lock assembly. WIRING DIAGRAM CAUTION / NOTICE / HINT NOTICE: Before replacing the main ECU (multiplex network body ECU), refer to Registration*1. Click here *1: w/ S ...

    Toyota CH-R Service Manual > Can Communication System: Open in Bus 5 Main Bus Line
    DESCRIPTION There may be an open circuit in one of the CAN main bus lines when the resistance between terminals 15 (CA5H) and 16 (CA5L) of the central gateway ECU (network gateway ECU) is 70 Ω or higher. Symptom Trouble Area Resistance between terminals ...

    Toyota C-HR (AX20) 2023-2025 Owner's Manual

    Toyota CH-R Owners Manual

    Toyota CH-R Service Manual

    © 2017-2025 Copyright www.tochr.net
    0.019