Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM1000000018KDQ
Model Year Start: 2018 Model: Sienna Prod Date Range: [11/2017 -           ]
Title: BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: PRECAUTION; 2018 - 2020 MY Sienna [11/2017 -        ]

PRECAUTION

1. IGNITION SWITCH EXPRESSIONS

(a) The type of ignition switch used on this model differs according to the specifications of the vehicle. The expressions listed in the table below are used in this section.

Expression

Switch (Position)

Engine Switch (Condition)

Ignition switch off

LOCK

Off

Ignition switch ACC

ACC

On (ACC)

Ignition switch ON

ON

On (IG)

Engine start

START

Start

2. TROUBLESHOOTING PRECAUTIONS

(a) When there is a malfunction with terminal contact points or part installation problems, removal and installation of the suspected parts may return the system to normal either completely or temporarily.

(b) In order to determine the malfunctioning area, be sure to check the conditions at the time the malfunction occurred, such as DTC output and the Freeze Frame Data, and record it before disconnecting any connector or removing and installing parts.

(c) Since the system may be influenced by malfunctions in systems other than the VSC system, be sure to check for DTCs in other systems.

3. HANDLING PRECAUTIONS

(a) Do not remove or install VSC parts such as the steering angle sensor (spiral cable with sensor sub-assembly) or yaw rate and acceleration sensor (airbag sensor assembly) except when required, as they need to be adjusted correctly after removal and installation.

(b) Be sure to perform preparation before work and confirmation after work is completed by following the directions in the repair manual when working on the VSC system.

(c) Be sure to remove and install the ECU, brake actuator assembly, sensors, etc. with the ignition switch off unless it is otherwise specified in the inspection procedure.

(d) If the ECU, brake actuator assembly or a sensor has been removed and installed, it is necessary to check the system for problems after the parts have been reassembled. Check for DTCs using the Techstream. Also check that the system functions and signals received by the ECU are normal using Test Mode.

4. DTC PRECAUTION

(a) Warnings for some DTCs cannot be cleared only by repairing the malfunctioning parts. If the warning is displayed after repair work, the DTC should be cleared after turning the ignition switch off.

NOTICE:

If a DTC for a malfunctioning part reappears after it was cleared, then it has been stored again.

5. CHASSIS DYNAMOMETER PRECAUTION

When testing with a 2-wheel drum tester such as a speedometer tester, a combination tester for the speedometer and brakes, or chassis dynamometer, or when jacking up the front wheels and turning the wheels, perform the following procedure to enter Inspection Mode and disable the TRAC and VSC systems.

NOTICE:

  • Secure the vehicle with lock chains for safety.
  • When performing procedures related to VSC OFF switch operation, make sure that the mode is VSC OFF mode.

HINT:

  • If Inspection Mode is not used, the vehicle may unexpectedly move off the dynamometer because of TRAC and VSC operation.
  • The VSC OFF switch must not be used to disable TRAC and VSC operation when the vehicle is to be operated on a dynamometer. Pressing the VSC OFF switch does not disable TRAC and VSC operation completely.

(a) Activating Inspection Mode (When Using Techstream)

(1) Ensure that the ignition switch is off and the engine is stopped.

(2) Make sure that the shift lever is in P.

(3) Connect the Techstream to the DLC3.

(4) Turn the ignition switch to ON.

(5) Turn the Techstream on.

(6) Enter the following menus: Chassis / ABS/VSC/TRAC / Utility / Inspection Mode.

(7) Check that the VSC OFF indicator light comes on and the TRAC OFF message will be displayed on the multi-information display.

HINT:

  • If the VSC OFF indicator light does not come on and the TRAC OFF message is not displayed on the multi-information display, repeat the steps above.
  • Turning the ignition switch off ends Inspection Mode.

(b) Activating Inspection Mode (When not Using Techstream)

HINT:

Perform steps "D" to "H" within 30 seconds.

(1) Ensure that the ignition switch is off and the engine is stopped (Step "A").

(2) Make sure that the shift lever is in P (Step "B").

(3) With the brake pedal depressed, start the engine (Step "C").

(4) While holding the brake pedal down, apply the parking brake (Step "D").

(5) With the parking brake applied, depress and release the brake pedal twice (Step "E").

(6) While holding the brake pedal down, release and apply the parking brake twice (Step "F").

(7) With the parking brake applied, depress and release the brake pedal twice (Step "G").

(8) Check that the VSC OFF indicator light comes on and the TRAC OFF message is displayed on the multi-information display (Step "H").

HINT:

  • If the slip indicator light does not come on in step "H", repeat steps "A" to "H".
  • Turning the ignition switch off ends Inspection Mode.

6. CAN COMMUNICATION SYSTEM PRECAUTIONS

(a) The CAN communication system is used for communication between the skid control ECU (brake actuator assembly), steering angle sensor (spiral cable with sensor sub-assembly), yaw rate and acceleration sensor and other ECUs. If there is a malfunction e in a CAN communication line, corresponding DTCs in the communication line are output.

(b) If any CAN communication DTCs are output, repair the malfunction, then troubleshoot the VSC system while communication is normal.

(c) In order to enable CAN communication, a specific type of wiring is used for the CAN communication lines. The wiring used for each communication line is a twisted pair of wires that have an equal length. A bypass wire should not be used because the data being transmitted will be corrupted.