Toyota Tundra Service Manual: Brake Warning Light does not Come ON

DESCRIPTION

The skid control ECU (brake actuator assembly) is connected to the combination meter assembly via CAN communication.

CAUTION / NOTICE / HINT

NOTICE:

When replacing the skid control ECU (brake actuator assembly), perform system variant learning and acceleration zero point calibration.
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Inspect the fuses for circuits related to this system before performing the following procedure.

PROCEDURE

1.	CHECK CAN COMMUNICATION SYSTEM

(a) Check if CAN communication system DTCs are output.

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Result	Proceed to
DTCs are not output	A
DTCs are output	B

INSPECT CAN COMMUNICATION SYSTEM

2.	PERFORM ACTIVE TEST USING TECHSTREAM (BRAKE WARNING LIGHT)

(a) Enter the following menus: Chassis / ABS/VSC/TRAC / Active Test.

ABS/VSC/TRAC

Tester Display	Measurement Item	Control Range	Diagnostic Note
Brake Warning Light	Brake warning light	Warning light OFF/ON	Observe combination meter assembly

ABS/VSC/TRAC

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Brake Warning Light

Brake warning light

ON or OFF

ON: Warning light on

OFF: Warning light off

(b) Check the operating condition of the brake warning light when operating it using the Techstream.

Result	Proceed to
Brake warning light in the Data List does not change using the Active Test	A
Brake warning light in the Data List turns ON/OFF using the Active Test	B

REPLACE BRAKE ACTUATOR ASSEMBLY

3.	INSPECT COMBINATION METER ASSEMBLY

(a) Enter the following menus: Body Electrical / Combination Meter / Active Test.

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(b) Perform the Active Test of the combination meter assembly using the Techstream.

OK:

The brake warning light turns on or off in accordance with the Techstream operation.

REPLACE BRAKE ACTUATOR ASSEMBLY

INSPECT METER / GAUGE SYSTEM

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Toyota Tundra Owners Manual