Toyota Sienna Service Manual: Brake Warning Light Remains ON
DESCRIPTION
The BRAKE warning light comes on when the brake fluid is insufficient, the parking brake is applied or the EBD is defective.
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT: When releasing the parking brake, move the shift lever into the P position in an AT vehicle, and choke in an MT vehicle to hold the vehicle for safety.
1 CHECK BRAKE FLUID LEVEL
(a) Check that the brake fluid level is proper.
2 CHECK DTC
(a) Are the DTC recorded? (See page BC-82)
Result 
REPAIR CIRCUITS INDICATED BY OUTPUT DTCS
3 CHECK BRAKE WARNING LIGHT
ABS / VSC: 
(a) WHEN USING INTELLIGENT TESTER: (1) Connect the intelligent tester to the DLC3.
(2) Start the engine.
(3) Select the item "BRAKE WARN LIGHT" in the ACTIVE TEST and operate the BRAKE warning light on the intelligent tester.
(4) Check that "ON" and "OFF" of the BRAKE warning light are indicated on the combination meter when using the intelligent tester.
OK: Turn the BRAKE warning light on or off in accordance with the intelligent tester.
(b) WHEN NOT USING INTELLIGENT TESTER: (1) Turn the ignition switch off and disconnect the connector from the skid control ECU.
(2) Ground terminal BRL of the skid control ECU.
(3) Turn the ignition switch to the ON position.
(4) Check that the brake warning light.
OK: Turn the light on or off in accordance with the connection of terminal GND and BRL.
NOTICE: When replacing the brake actuator assembly, perform zero point calibration (See page BC-70).
REPLACE BRAKE ACTUATOR ASSEMBLY
4 INSPECT PARKING BRAKE SWITCH
(a) Remove the parking brake switch connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance 
5 CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - PARKING BRAKE SWITCH)
(a) Disconnect the skid control ECU connector and the parking brake switch connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance 
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance 
6 INSPECT BRAKE FLUID LEVEL WARNING SWITCH
(a) Remove the reservoir tank cap and strainer.
(b) Disconnect the brake fluid level warning switch connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance 
7 CHECK HARNESS AND CONNECTOR (BRAKE FLUID LEVEL WARNING SWITCH - COMBINATION METER)
(a) Disconnect the combination meter connector and the brake fluid level warning switch connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance 
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance 
REPAIR OR REPLACE COMBINATION METER ASSEMBLY
VSC Warning Light does not Come ON
DESCRIPTION
The skid control ECU is connected to the combination meter via CAN and
multiplex communications.
If the skid control ECU stores DTCs to shut down TRAC and VSC operation, the VSC
wa ...
TRAC OFF Indicator Light Remains ON
DESCRIPTION
The skid control ECU is connected to the combination meter via CAN and
multiplex communications.
When the traction OFF switch is turned on, the TRAC OFF indicator light will
come o ...
Other materials:
Diagnostic trouble code chart
HINT:
The parameters listed in the chart may not confirm exactly to
those read during the DTC check due to the type of
instrument or other factors.
If a trouble code is displayed during the DTC check in the
check mode, check the circuit for the code listed in the table
below. For details of ...
Inspection
1. INSPECT OUTER REAR VIEW MIRROR ASSEMBLY LH (w/o Memory)
Disconnect the mirror connector.
Check operation of the outer mirror.
Apply battery voltage and inspect operation of
the mirror face, as shown in the table and
illustration.
Standard (LH)
If the result i ...
Problem symptoms table
HINT:
Before performing verification listed in the table below,
check the fuse and relay.
Check the circuits for each problem symptom in the order
given in the table below, and proceed to the relevant page.
CLEARANCE SONAR SYSTEM:
*1: with Front Clearance Sonar
*2: wit ...
