DTC B2284: Brake Signal Malfunction: Procedure

1. Connect Techstream to the DLC3.
2. Turn the engine switch on (IG) and press Techstream main switch on.
3. Read the Data List according to the displays on the tester.
   POWER SOURCE CONTROL:
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Stop Light SW	Stop light switch signal / ON or OFF	ON: Brake pedal depressed OFF: Brake pedal released	-

   OK

   "ON" (brake pedal depressed) appears on the screen.

   Result

   Condition	Proceed to
   NG	C
   OK (When troubleshooting according to the PROBLEM SYMPTOM TABLE)	B
   OK (When troubleshooting according to the DTC chart)	A

B → PROCEED TO  PROBLEM SYMPTOMS TABLE  NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE 

C → See step   2 

A → REPLACE POWER SOURCE CONTROL ECU 

1. Disconnect the stop light switch assembly connector.
   Fig 1: Identifying Stop Light Switch Assembly Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Resistance

   Switch condition	Tester connection	Specified value
   Switch pin free	1 - 2	Below 1 Ω
   Switch pin free	3 - 4	10 kΩ or higher
   Switch pin pushed in	1 - 2	10 kΩ or higher
   Switch pin pushed in	3 - 4	Below 1 Ω

NG → REPLACE STOP LIGHT SWITCH ASSEMBLY 

OK: Go to next step 

1. Disconnect the A23 switch connector.
   Fig 2: Identifying A23 Switch Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the D44 ECU connector.
   Fig 3: Identifying D44 ECU Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Measure the resistance according to the value(s) in the table below.

   Resistance

   Terminal No. (Symbol)	Specified Condition
   A23-1 - D44-1 (STP)	Below 1 Ω
   A23-1 - Body ground	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → REPLACE POWER SOURCE CONTROL ECU