THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): B2284; Brake Signal Malfunction; 2021 MY Avalon [08/2020 - 08/2021]

Last Modified: 08-21-2023	6.11:8.1.0	Doc ID: RM100000001R16V
Model Year Start: 2021	Model: Avalon	Prod Date Range: [08/2020 - 08/2021]
Title: THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): B2284; Brake Signal Malfunction; 2021 MY Avalon [08/2020 - 08/2021]

DTC

B2284

Brake Signal Malfunction

DESCRIPTION

This DTC is stored when the brake signal sent via direct line and the brake signal sent via CAN communication do not match.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Note
B2284	Brake Signal Malfunction	The brake signal sent via direct line and the brake signal sent via CAN communication do not match. (1-trip detection logic*)	Stop light switch assembly SFI system Certification ECU (smart key ECU assembly) Wire harness or connector	DTC Output Confirmation Operation: Connect the cable to the negative (-) battery terminal, release the brake pedal and wait at least 20 seconds. Then depress the brake pedal for 20 seconds or more.

*: Only detected while a malfunction is present and the engine switch is on (IG).

Vehicle Condition and Fail-safe Function when Malfunction Detected

Vehicle Condition when Malfunction Detected

Fail-safe Function when Malfunction Detected

With the electrical key transmitter sub-assembly in the cabin, even if an engine start operation is performed, the engine does not start (the key indicator display is not displayed on the multi-information display). However, the engine can be started by turning the engine switch on (ACC) and then pressing and holding it.

If there is a malfunction when the brake signal sent via direct line is on, the engine can be started by pressing the engine switch with the brake pedal released.
If there is a malfunction when the brake signal sent via direct line is off, the engine cannot be started by pressing the engine switch with the brake pedal depressed.

-

Related Data List and Active Test Items

DTC No.	Data List and Active Test
B2284	Power Source Control Stop Light Switch1 Engine Stop Light SW

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, Gasoline Model) 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, Gasoline Model) after confirming that the communication systems are functioning properly.
Click here
Inspect the fuses of circuits related to this system before performing the following procedure.
Before replacing the certification ECU (smart key ECU assembly), refer to Registration.
Click here
After repair, confirm that no DTCs are output by performing "DTC Output Confirmation Operation".

PROCEDURE

1.	READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH1)

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Power Source Control / Data List.

(e) Read the Data List according to the display on the Techstream.

Body Electrical > Power Source Control > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Stop Light Switch1

State of brake pedal

OFF or ON

OFF: Brake pedal released

ON: Brake pedal depressed

Use this item to determine if the stop light switch assembly is malfunctioning.
The engine cannot be started when this item is OFF.
If the stop light switch assembly is malfunctioning, the engine can be started by pressing and holding the engine switch for a certain period of time.

Body Electrical > Power Source Control > Data List

Tester Display
Stop Light Switch1

OK:

The Techstream display changes correctly in response to the brake pedal operation.

OK

GO TO SFI SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING)

for 2GR-FKS: Click here

for A25A-FKS: Click here

NG

2.	CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - STOP LIGHT SWITCH ASSEMBLY)

(a) Disconnect the K10 certification ECU (smart key ECU assembly) connector.

(b) Disconnect the A33 stop light switch assembly connector.

(c) Disconnect the A18*1 or A64*2 ECM connector.

*1: for 2GR-FKS
*2: for A25A-FKS

(d) Disconnect the A28 skid control ECU (brake actuator assembly) connector.

(e) Disconnect the G21 shift lock control unit assembly connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
K10-25 (STP1) - A33-3 (L)	Always	Below 1 Ω

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

3.	CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

(a) Connect the K10 certification ECU (smart key ECU assembly) connector.

(b) Connect the A33 stop light switch assembly connector.

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
K10-25 (STP1) - Body ground	Brake pedal released → depressed	1 V or less → 9 V or higher

*a	Component with harness connected (Certification ECU (Smart Key ECU Assembly))

OK

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

NG

REPLACE STOP LIGHT SWITCH ASSEMBLY