DTC B2284: Brake Signal Malfunction [08/2015 - 08/2019]: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG).
3. Turn the Techstream on.
4. Enter the following menus: Body Electrical / Power Source Control / Data List.
5. According to the display on the Techstream, read the Data List.
   POWER SOURCE CONTROL
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Stop Light Switch1	State of brake pedal/ON or OFF	ON: Brake pedal depressed OFF: Brake pedal released	Use this item to determine whether the stop light switch is malfunctioning. The engine cannot be started when this item is "OFF". When this item is malfunctioning, the engine can be started by pressing and holding the engine switch for a certain period of time.

   OK

   ON (brake pedal depressed) or OFF (brake pedal released) appears on the screen according to the stop light switch condition.

Result: 

OK 

GO TO SFI SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) 

(Refer to HOW TO PROCEED WITH TROUBLESHOOTING [08/2015 - ] )

Result: 

NG 

See step  2

See step  1

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR IN CIRCUIT CONNECTED TO POWER SOURCE 

Result: 

OK 

See step  3

See step  2

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  4

1. Disconnect the G38 power management control ECU connector.
2. Disconnect the A5 stop light switch assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   G38-11 (STP1) - A5-2 (L)	Always	Below 1 Ω
   G38-11 (STP1) or A5-2 (L) - Body ground	Always	10 kΩ or higher
   A5-3 (GND) - Body ground	Always	Below 1 Ω

4. Reconnect the A5 stop light switch assembly connector.
5. Measure the voltage according to the value(s) in the table below.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   G38-11 (STP1) - Body ground	Brake pedal not depressed	Below 1 V
   	Brake pedal depressed	9 V or higher

   TEXT IN ILLUSTRATION
   
   

   *a	Rear view of wire harness connector (to Power Management Control ECU)

Result: 

OK 

REPLACE POWER MANAGEMENT CONTROL ECU 

(Refer to REMOVAL [08/2015 - 08/2019] )

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR