DTC B2284: Brake Signal Malfunction: Procedure

WARNING: This page is about a different car, the 2011 Lexus RX 350. However, it is still accessible from the selected car via links, so may be relevant.

CHECK HARNESS AND CONNECTOR (BATTERY - POWER MANAGEMENT CONTROL ECU) See step 1
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - POWER MANAGEMENT CONTROL ECU)

OK: Go to next step
CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - BODY GROUND) See step 2
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER MANAGEMENT CONTROL ECU - BODY GROUND)

OK: Go to next step

INSPECT STOP LIGHT SWITCH ASSEMBLY

Remove the stop light switch assembly. Refer to REMOVAL .

Fig 1: Identifying Stop Light Switch Assembly
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Standard Resistance

Tester Connection	Condition	Specified Condition
1 - 2	Pushed	10 kΩ or higher
3 - 4	Pushed	10 kΩ or higher
1 - 2	Not pushed	Below 1 Ω
3 - 4	Not pushed	Below 1 Ω

TEXT IN ILLUSTRATION

*1	Component without harness connected (Stop Light Switch Assembly)
*2	Free
*3	Pushed in

NG → See step 6

OK: Go to next step

CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - POWER MANAGEMENT CONTROL ECU)

Disconnect the F7 connector from the power management control ECU.

Fig 2: F7 & A47 Connectors
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Standard Resistance

Tester Connection	Condition	Specified Condition
F7-11 (STP1) - A47-1	Always	Below 1 Ω
F7-11 (STP1) - Body ground	Always	10 kΩ or higher

TEXT IN ILLUSTRATION

*1	Front view of wire harness connector (to Power Management Control ECU)
*2	Front view of wire harness connector (to Stop Light Switch Assembly)

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - POWER MANAGEMENT CONTROL ECU)

OK: Go to next step

READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH ASSEMBLY)

Connect the Techstream to the DLC3.
Turn the engine switch on (IG).
Turn the Techstream on.
Enter the following menus: Body Electrical / Power Source Control / Data List.

Read the Data List according to the display on the Techstream.

POWER SOURCE CONTROL

Tester Display	Measurement Item/Range	Normal Condition	Specified Condition
Stop Light Switch1	Stop light switch1/ON or OFF	ON: Brake pedal depressed OFF: Brake pedal released	-

ON and OFF appear on the screen.

NG → See step 7

OK → See step 8

REPLACE STOP LIGHT SWITCH ASSEMBLY. Refer to REMOVAL
REPLACE POWER MANAGEMENT CONTROL ECU. Refer to REMOVAL
GO TO SFI SYSTEM. Refer to HOW TO PROCEED WITH TROUBLESHOOTING