This mode employs a radar sensor to detect the presence of vehicles up to approximately 400 ft. (120 m) ahead, determines the current vehicle-to-vehicle following distance, and operates to maintain a suitable following distance from the vehicle ahead.
Note that vehicle-to-vehicle distance will close in when traveling on long downhill slopes.

The vehicle travels at the speed set by the driver. The desired vehicle-tovehicle distance can also be set by operating the vehicle-to-vehicle distance control.
When a vehicle is detected running ahead of you, the system automatically decelerates your vehicle. When a greater reduction in vehicle speed is necessary, the system applies the brakes. A warning tone warns you when the system cannot decelerate sufficiently to prevent your vehicle from closing in on the vehicle ahead.
The system continues follow-up cruising while adjusting for changes in the speed of the vehicle ahead in order to maintain the vehicle-to-vehicle distance set by the driver.
The system accelerates until the set speed is reached. The system then returns to constant speed cruising.
Canceling and resuming the speed control
Approach warningNo. 2 Ultrasonic sensor
COMPONENTS
REMOVAL
1. REMOVE REAR BUMPER COVER (2)
2. REMOVE NO. 1 ULTRASONIC SENSOR RETAINER
Remove the No. 1 ultrasonic sensor retainer as
shown in the illustration
3. REMOVE NO. 2 ULTRASONIC SENSOR
Disconnect the connector and remove the No. 2
ultrasonic ...
Child restraint systems with a top tether strap (second seat)
Secure the child restraint system
using the seat belt or
LATCH anchors, and adjust the
head restraint to the uppermost
position.
*: Ottoman seat only
Latch the hook onto the anchor
bracket and tighten the top
tether strap.
Make sure the top tether strap is
secure ...
Symptom confirmation and diagnostic trouble code
HINT:
The diagnostic system in the SIENNA has various
functions.
The first function is the Diagnostic Trouble Code
(DTC) check. A DTC is a code stored in the ECU
memory whenever a malfunction in the signal circuits
to the ECU occurs. In a DTC check, a previous
malfunction's DTC can be ...