Toyota Sienna Service Manual: System description
1. SYSTEM DESCRIPTION
(a) ABS
(Anti-lock Brake System) The ABS helps prevent wheels from locking when the brake is applied firmly or when braking on a slippery surface.
(b) EBD
(Electronic Brake force Distribution) The EBD control utilizes ABS, realizing proper brake force distribution between front and rear wheels in accordance with driving conditions. In addition, during cornering braking, it also controls the brake force of the right and left wheels, helping to maintain vehicle behavior.
(c) BA (Brake Assist)
The primary purpose of the brake assist system is to provide an auxiliary brake force to assist the driver who cannot generate a large enough brake force during emergency braking, thus helping to maximize the vehicle's brake performance.
(d) TRAC
(Traction Control) The TRAC system helps prevent the drive wheels from slipping if drive presses down on the accelerator pedal excessively when starting off or accelerating on a slippery surface.
(e) VSC
(Vehicle Stability Control) The VSC system helps prevent the vehicle from slipping sideways as a result of strong front wheel skid or strong rear wheel skid during cornering.
Vehicle stability control system
Parts location
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How to proceed with troubleshooting
The intelligent tester can be used at step 2, 5, 8, 11.
1 Vehicle Brought to Workshop
2 Check and Clear DTCs and Freeze Frame Data
HINT:
See page BC-82 and BC-84.
3 Problem Symptom Confirmati ...
Other materials:
Starter Relay Circuit High
MONITOR DESCRIPTION
While the engine is being cranked, the positive battery voltage is applied to
terminal STA of the ECM.
If the ECM detects the Starter Control (STA) signal while the vehicle is being
driven, it determines that
there is a malfunction in the STA circuit. The ECM then il ...
TRAC OFF Indicator Light does not Come 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 on (for 2WD model).
WIRING DIAGRAM
Refer to TRAC OFF Indicator Light Remains ON (See page BC-157).
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System check
HINT:
Performing a SYSTEM CHECK enables the system,
which consists of the multiple actuators, to be operated
without removing any parts. In addition, it can show
whether or not any DTCs are set, and can detect
potential malfunctions in the system. The SYSTEM
CHECK can be performed with an inte ...
