Last Modified: 01-30-2024 6.11:8.1.0 Doc ID: RM1000000021J3Y
Model Year Start: 2022 Model: RAV4 Prod Date Range: [12/2021 -           ]
Title: THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): B279986; Engine Immobiliser System Signal (Some Circuit Quantity, Reported via Serial Data) Invalid; 2022 - 2024 MY RAV4 [12/2021 -        ]

DTC

B279986

Engine Immobiliser System Signal (Some Circuit Quantity, Reported via Serial Data) Invalid

DESCRIPTION

If there is a communication malfunction between the ECM and ID code box (immobiliser code ECU), or when the communication ID codes do not match, the ECM stores this DTC.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Note

B279986

Engine Immobiliser System Signal (Some Circuit Quantity, Reported via Serial Data) Invalid

Either of the following conditions is met (1 trip detection logic*):

  • A malfunction is detected in the communication or communication lines between the ECM and ID code box (immobiliser code ECU).
  • The communication ID codes of the ECM and ID code box (immobiliser code ECU) do not match.
  • ID code box (immobiliser code ECU)
  • ECM
  • Harness or connector

DTC output confirmation operation (Perform either of the following):

  • Start the engine and wait for 10 seconds. If there is a malfunction, the engine will stop (communication begins within 3 seconds of the engine start, and DTCs are stored after 6 seconds).
  • Connect the cable to the negative (-) battery terminal, start the engine and wait for 10 seconds (communication begins within 3 seconds of the engine switch being turned on (IG), and DTCs are stored after 6 seconds).
  • *: Only output while a malfunction is present.

Vehicle Condition and Fail-safe Operation when Malfunction Detected

Vehicle Condition when Malfunction Detected

Fail-safe Operation when Malfunction Detected

Engine cannot be started

-

Related Data List and Active Test

DTC No.

Data List and Active Test

B279986

-

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • 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 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.
  • The smart key system (for Start Function) uses the LIN communication system and CAN communication system. Inspect the communication function by following How to Proceed with Troubleshooting. Troubleshoot the smart key system (for Start Function) after confirming that the communication systems are functioning properly.

    Click here 2022 - 2023 MY RAV4 [12/2021 - 10/2023]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): HOW TO PROCEED WITH TROUBLESHOOTING 2024 MY RAV4 [10/2023 -        ]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): HOW TO PROCEED WITH TROUBLESHOOTING

  • Before replacing the ECM, ID code box (immobiliser code ECU), refer to the Registration.

    Click here 2022 - 2024 MY RAV4 [12/2021 -        ]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): REGISTRATION

  • After repair, confirm that no DTCs are output by performing "DTC Output Confirmation Operation".

HINT:

When DTC B279986 and a certification ECU (smart key ECU assembly) DTC are output simultaneously, first perform troubleshooting for the certification ECU (smart key ECU assembly) DTC.

PROCEDURE

1.

REGISTER ECU COMMUNICATION ID (ID CODE BOX (IMMOBILISER CODE ECU) - ECM)

(a) Register the communication ID codes.

HINT:

Refer to Registration.

Click here 2022 - 2024 MY RAV4 [12/2021 -        ]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): REGISTRATION

NEXT

2.

CHECK ECM (TERMINAL EFII)

(a) Using an oscilloscope, check the waveform.

*a

Component with harness connected

(ID Code Box (Immobiliser Code ECU))

*b

Waveform

*c

Approximately 160 ms.

*d

Approximately 270 ms.

Measurement Condition:

Tester Connection

Condition

Tool Setting

Specified Condition

G57-3 (EFII) - Body ground

Within 3 seconds of engine start or within 3 seconds of engine switch turned on (IG) after cable disconnected and reconnected to battery

2 V/DIV., 500 ms./DIV.

Pulse generation

(See waveform)

Result

Proceed to

Normal waveform

A

Terminal EFII stuck low (2.4 V or less)

B

Waveform length or shape is abnormal, or EFII terminal stuck at Hi (12 V)

C

B

GO TO STEP 6

C

REPLACE ECM 2021 - 2022 MY RAV4 [08/2020 - 10/2022]; A25A-FKS (ENGINE CONTROL): ECM: REMOVAL 2023 MY RAV4 [10/2022 - 10/2023]; A25A-FKS (ENGINE CONTROL): ECM: REMOVAL 2024 MY RAV4 [10/2023 -        ]; A25A-FKS (ENGINE CONTROL): ECM: REMOVAL

A

3.

CHECK ID CODE BOX (IMMOBILISER CODE ECU) (TERMINAL EFIO)

(a) Using an oscilloscope, check the waveform.

*a

Component with harness connected

(ID Code Box (Immobiliser Code ECU))

*b

Waveform

*c

Approximately 160 ms.

*d

Approximately 270 ms.

Measurement Condition:

Tester Connection

Condition

Tool Setting

Specified Condition

G57-4 (EFIO) - Body ground

Within 3 seconds of engine start or within 3 seconds of engine switch turned on (IG) after cable disconnected and reconnected to battery

2 V/DIV., 500 ms./DIV.

Pulse generation

(See waveform)

NG

REPLACE ID CODE BOX (IMMOBILISER CODE ECU) 2022 MY RAV4 RAV4 HV [12/2021 - 10/2022]; THEFT DETERRENT / KEYLESS ENTRY: ID CODE BOX: REMOVAL 2023 MY RAV4 RAV4 HV [10/2022 - 10/2023]; THEFT DETERRENT / KEYLESS ENTRY: ID CODE BOX: REMOVAL 2024 MY RAV4 RAV4 HV [10/2023 -        ]; THEFT DETERRENT / KEYLESS ENTRY: ID CODE BOX: REMOVAL

OK

4.

REGISTER ECU COMMUNICATION ID (ID CODE BOX (IMMOBILISER CODE ECU) - ECM)

(a) Register the ECU communication ID codes.

HINT:

Refer to Registration.

Click here 2022 - 2024 MY RAV4 [12/2021 -        ]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): REGISTRATION

NEXT

5.

CHECK WHETHER ENGINE STARTS

(a) Check that the engine starts.

Result

Proceed to

Engine was started

A

Engine was not started

B

A

END (ECU COMMUNICATION ID HAS NOT BEEN REGISTERED)

B

REPLACE ECM 2021 - 2022 MY RAV4 [08/2020 - 10/2022]; A25A-FKS (ENGINE CONTROL): ECM: REMOVAL 2023 MY RAV4 [10/2022 - 10/2023]; A25A-FKS (ENGINE CONTROL): ECM: REMOVAL 2024 MY RAV4 [10/2023 -        ]; A25A-FKS (ENGINE CONTROL): ECM: REMOVAL

6.

CHECK ECM (TERMINAL IMO)

(a) Disconnect the ECM connector.

*a

Front view of wire harness connector

(to ECM)

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

A24-25 (IMO) - Body ground

Engine switch turned on (IG) using registered electrical key transmitter sub-assembly

Terminal IMO stuck low (2.4 V or less)

Terminal IMO stuck high (12 V)

Result

Proceed to

Terminal IMO stuck low (2.4 V or less)

A

Terminal IMO stuck high (12 V)

B

B

REPLACE ECM 2021 - 2022 MY RAV4 [08/2020 - 10/2022]; A25A-FKS (ENGINE CONTROL): ECM: REMOVAL 2023 MY RAV4 [10/2022 - 10/2023]; A25A-FKS (ENGINE CONTROL): ECM: REMOVAL 2024 MY RAV4 [10/2023 -        ]; A25A-FKS (ENGINE CONTROL): ECM: REMOVAL

A

7.

CHECK HARNESS AND CONNECTOR (ID CODE BOX (IMMOBILISER CODE ECU) - ECM)

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

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

G57-3 (EFII) - A24-25 (IMO)

Always

Below 1 Ω

G57-3 (EFII) or A24-25 (IMO) - Other terminals and body ground

Always

10 kΩ or higher

OK

REPLACE ID CODE BOX (IMMOBILISER CODE ECU) 2022 MY RAV4 RAV4 HV [12/2021 - 10/2022]; THEFT DETERRENT / KEYLESS ENTRY: ID CODE BOX: REMOVAL 2023 MY RAV4 RAV4 HV [10/2022 - 10/2023]; THEFT DETERRENT / KEYLESS ENTRY: ID CODE BOX: REMOVAL 2024 MY RAV4 RAV4 HV [10/2023 -        ]; THEFT DETERRENT / KEYLESS ENTRY: ID CODE BOX: REMOVAL

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR