LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2021 >> RX 350 Base, AWD >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Anti-Theft Systems >> Smart Access System With Push-Button Start (For Start Function) - Diagnostic Codes & Symptom Tests >> SMART ACCESS SYSTEM WITH PUSH-BUTTON START (for Start Function) >> DTC B2284: Brake Signal Malfunction [09/2015 - ] >> Description
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC B2284: Brake Signal Malfunction [09/2015 - ]: 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*)
  • AM2 fuse
  • STOP fuse
  • Stop light switch assembly
  • SFI system
  • Certification ECU (smart key ECU assembly)
  • Wire harness or connector
DTC Output Confirmation Operation: 
  1. 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.
  1. *: 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