Last Modified: 01-30-2024 6.11:8.1.0 Doc ID: RM100000001FNIA
Model Year Start: 2019 Model: RAV4 Prod Date Range: [11/2018 - 12/2021]
Title: NETWORKING: LIN COMMUNICATION SYSTEM: B2785; Communication Malfunction between ECUs Connected by LIN; 2019 - 2021 MY RAV4 RAV4 HV [11/2018 - 12/2021]

DTC

B2785

Communication Malfunction between ECUs Connected by LIN

DESCRIPTION

If the certification ECU (smart key ECU assembly) detects a communication error with an ECU connected to the certification bus lines for 7 seconds or more, DTC B2785 will be stored.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

B2785

Communication Malfunction between ECUs Connected by LIN

  • Errors in LIN communication between ECUs or an open or short in communication lines.
  • The certification ECU (smart key ECU assembly) detects a communication error with an ECU connected to the certification bus lines for 7 seconds or more.
  • Certification ECU (smart key ECU assembly)
  • Steering lock actuator with ECU assembly
  • ID code box (immobiliser code ECU)
  • Harness or connector

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • Before performing the inspection, check that DTC B2786 or B278C is not output.

    Click here 2019 - 2024 MY RAV4 RAV4 HV [11/2018 -        ]; NETWORKING: LIN COMMUNICATION SYSTEM: DTC CHECK / CLEAR

  • 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 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), ID code box (immobiliser code ECU) or steering lock actuator with ECU assembly, refer to Registration.

    for HV Model: Click here 2019 MY RAV4 HV [11/2018 - 10/2019]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): REGISTRATION 2020 - 2021 MY RAV4 HV [10/2019 - 12/2021]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): REGISTRATION

    for Gasoline Model: Click here 2019 MY RAV4 [11/2018 - 10/2019]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): REGISTRATION 2020 MY RAV4 [10/2019 - 08/2020]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): REGISTRATION 2021 MY RAV4 [08/2020 - 12/2021]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): REGISTRATION

PROCEDURE

1.

CHECK FOR DTC

(a) Clear the DTCs.

Click here 2019 - 2024 MY RAV4 RAV4 HV [11/2018 -        ]; NETWORKING: LIN COMMUNICATION SYSTEM: DTC CHECK / CLEAR

Body Electrical > Smart Key > Clear DTCs

(b) Recheck for DTCs.

Click here 2019 - 2024 MY RAV4 RAV4 HV [11/2018 -        ]; NETWORKING: LIN COMMUNICATION SYSTEM: DTC CHECK / CLEAR

Body Electrical > Smart Key > Trouble Codes

Result

Proceed to

DTC B2785 is output

A

DTC B2785 is not output

B

B

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) 2019 MY RAV4 RAV4 HV [11/2018 - 02/2019]; THEFT DETERRENT / KEYLESS ENTRY: CERTIFICATION ECU: REMOVAL 2019 MY RAV4 RAV4 HV [02/2019 - 10/2019]; THEFT DETERRENT / KEYLESS ENTRY: CERTIFICATION ECU: REMOVAL 2020 MY RAV4 RAV4 HV [10/2019 - 08/2020]; THEFT DETERRENT / KEYLESS ENTRY: CERTIFICATION ECU: REMOVAL 2021 MY RAV4 RAV4 HV [08/2020 - 12/2021]; THEFT DETERRENT / KEYLESS ENTRY: CERTIFICATION ECU: REMOVAL

A

2.

CHECK STEERING LOCK ACTUATOR WITH ECU ASSEMBLY

(a) Disconnect the G56 steering lock actuator with ECU assembly connector.

(b) Clear the DTCs.

Click here 2019 - 2024 MY RAV4 RAV4 HV [11/2018 -        ]; NETWORKING: LIN COMMUNICATION SYSTEM: DTC CHECK / CLEAR

Body Electrical > Smart Key > Clear DTCs

(c) Recheck for DTCs.

Click here 2019 - 2024 MY RAV4 RAV4 HV [11/2018 -        ]; NETWORKING: LIN COMMUNICATION SYSTEM: DTC CHECK / CLEAR

Body Electrical > Smart Key > Trouble Codes

Result

Proceed to

DTC B2785 is output

A

DTC B2785 is not output

B

B

REPLACE STEERING LOCK ACTUATOR WITH ECU ASSEMBLY

A

3.

CHECK ID CODE BOX (IMMOBILIZER CODE ECU)

(a) Disconnect the G57 ID code box (immobilizer code ECU) connector.

(b) Clear the DTCs.

Click here 2019 - 2024 MY RAV4 RAV4 HV [11/2018 -        ]; NETWORKING: LIN COMMUNICATION SYSTEM: DTC CHECK / CLEAR

Body Electrical > Smart Key > Clear DTCs

(c) Recheck for DTCs.

Click here 2019 - 2024 MY RAV4 RAV4 HV [11/2018 -        ]; NETWORKING: LIN COMMUNICATION SYSTEM: DTC CHECK / CLEAR

Body Electrical > Smart Key > Trouble Codes

Result

Proceed to

DTC B2785 is output

A

DTC B2785 is not output

B

B

REPLACE ID CODE BOX (IMMOBILIZER CODE ECU) 2019 MY RAV4 RAV4 HV [11/2018 - 02/2019]; THEFT DETERRENT / KEYLESS ENTRY: ID CODE BOX: REMOVAL 2019 MY RAV4 RAV4 HV [02/2019 - 10/2019]; THEFT DETERRENT / KEYLESS ENTRY: ID CODE BOX: REMOVAL 2020 MY RAV4 RAV4 HV [10/2019 - 08/2020]; THEFT DETERRENT / KEYLESS ENTRY: ID CODE BOX: REMOVAL 2021 MY RAV4 RAV4 HV [08/2020 - 12/2021]; THEFT DETERRENT / KEYLESS ENTRY: ID CODE BOX: REMOVAL

A

4.

CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - EACH ECU)

(a) Disconnect the G54 certification ECU (smart key ECU assembly) connector.

(b) Disconnect the G56 steering lock actuator with ECU assembly connector.

(c) Disconnect the G57 ID code box (immobiliser code ECU) connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

G54-13 (LIN) - G56-5 (LIN)

Always

Below 1 Ω

G54-13 (LIN) - G57-2 (LIN1)

Always

Below 1 Ω

G54-13 (LIN), G56-5 (LIN) or G57-2 (LIN1) - Body ground

Always

10 kΩ or higher

OK

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) 2019 MY RAV4 RAV4 HV [11/2018 - 02/2019]; THEFT DETERRENT / KEYLESS ENTRY: CERTIFICATION ECU: REMOVAL 2019 MY RAV4 RAV4 HV [02/2019 - 10/2019]; THEFT DETERRENT / KEYLESS ENTRY: CERTIFICATION ECU: REMOVAL 2020 MY RAV4 RAV4 HV [10/2019 - 08/2020]; THEFT DETERRENT / KEYLESS ENTRY: CERTIFICATION ECU: REMOVAL 2021 MY RAV4 RAV4 HV [08/2020 - 12/2021]; THEFT DETERRENT / KEYLESS ENTRY: CERTIFICATION ECU: REMOVAL

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR