SYSTEM DESCRIPTION GENERAL The
cruise control main switch is used to turn the dynamic radar cruise
control system on and off, as well as operate 7 functions: SET, -
(COAST), TAP-DOWN, RES (RESUME), + (ACCEL), TAP-UP and CANCEL. The SET,
TAP-DOWN, and - (COAST) functions, and the RES (RESUME), TAP-UP, and +
(ACCEL) functions are operated with the same switch. The cruise control
main switch is an automatic return type switch which turns on only while
operating it in the direction of each arrow and turns off after
releasing it. HINT: The
dynamic radar cruise control system has two cruise control modes:
constant speed control mode and vehicle-to-vehicle distance control mode
- Vehicle-to-vehicle distance control mode is selected by default when the
dynamic radar cruise control system is turned on using the cruise
control main switch (ON-OFF button).
- Operation of constant speed control mode is the same as that for a conventional cruise control system.
(a) This system maintains the
vehicle at the speed that the driver has set, as long as there are no
vehicles ahead. In addition to this, the system maintains the
vehicle-to-vehicle distance that has been set by the driver. If the
system detects a vehicle driving at a slower speed ahead while the
driver is driving at a constant speed, it controls the engine to
decelerate the vehicle. If further deceleration is required, the system
controls the brake actuator assembly in order to apply the brakes.
Thereafter, if there are no vehicles ahead within the set
vehicle-to-vehicle distance because either the vehicle ahead or the
driver has changed lanes, the system accelerates slowly to reach the set
speed and resumes driving at this speed. (b)
Vehicle-to-vehicle distance control mode is designed to control vehicle
speed and vehicle-to-vehicle distance using the constant speed function,
deceleration cruising function, follow-up cruising function, and
acceleration cruising function. (c) The millimeter
wave radar sensor assembly and forward recognition camera control the
system while vehicle-to-vehicle distance control mode is operating, and
send signals to each actuator and ECU. (d) In
vehicle-to-vehicle distance control mode, the dynamic radar cruise
control system receives signals from the forward recognition camera, yaw
rate sensor (airbag sensor assembly) and the steering sensor. Based on
these signals, the system then estimates curve radius and compensates
for information on the preceding vehicle while turning. It can also
compensate using brake control when approaching another vehicle. (e)
This system judges the presence of a vehicle in front and the distance
to it based on the signals from the millimeter wave radar sensor
assembly and forward recognition camera while vehicle-to-vehicle
distance control mode is operating. Using this information, the system
informs the driver of danger with the warning buzzer, performs brake
control, and turns on the stop lights when approaching a vehicle in
front. (f) The dynamic radar cruise control system performs the following controls (example).
HINT:
- Vehicle distance increases and decreases in accordance with vehicle speed.
- Control conditions are indicated on the multi-information display in the combination meter assembly.
|
*1 | Drives the vehicle at a constant speed (set speed: 100 km/h (60 mph)) |
*2 | Decelerates the vehicle from the set speed to the speed of the preceding vehicle (80 km/h (50 mph))* | |
*3 | Follows
the preceding vehicle while maintaining an appropriate
vehicle-to-vehicle distance according to the speed of the preceding
vehicle | *4 |
Gradually accelerates the vehicle to the set speed and maintains the speed |
*: Throttle valve control and brake control are performed to decelerate
the vehicle. If deceleration is insufficient and the distance to the
preceding vehicle becomes too short, the vehicle approach warning buzzer
sounds to warn the driver to take an appropriate action (braking,
etc.).
FUNCTION OF MAIN COMPONENTS (a) The main components of the dynamic radar cruise control system have the following functions: |
Component | Outline | |
Combination Meter Assembly | Cruise Control Indicator (Vehicle-to-vehicle Distance Control Mode) |
- Illuminates based on signals from the ECM when the dynamic radar cruise
control system is turned on using the cruise control main switch (ON-OFF
button).
- Turns off based on signals from the ECM or millimeter wave radar sensor
assembly when a malfunction is detected in the dynamic radar cruise
control system.
| | Cruise Control Indicator (Constant Speed Control Mode) |
Illuminates
when the dynamic radar cruise control system is turned on using the
cruise control main switch (ON-OFF button) and constant speed control
mode is selected. | | Cruise Control SET Indicator |
Illuminates when the vehicle speed is set. | |
Multi-information Display |
- Displays dynamic radar cruise control system information based on
signals from the ECM when the dynamic radar cruise control system is
turned on using the cruise control main switch (ON-OFF button).
- Displays a warning message if the ECM or millimeter wave radar sensor
assembly detects a malfunction signal while the dynamic radar cruise
control system is controlling vehicle speed.
| | Warning Buzzer |
Sounds
once to inform the driver if the ECM or millimeter wave radar sensor
assembly detects an automatic cancel signal while the dynamic radar
cruise control system is controlling vehicle speed. | |
Cruise Control Main Switch | ON-OFF Button |
- Turns the dynamic radar cruise control system on and off.
- Switches the control mode between constant speed control mode and vehicle-to-vehicle distance control mode.
| | CANCEL Switch |
A cancel signal is sent to the ECM when the switch is operated. | |
+RES Switch | Acceleration and stored speed resume signals are sent to the ECM when the switch is operated. | |
-SET Switch | Deceleration and vehicle speed setting signals are sent to the ECM when the switch is operated. | |
Distance Control Switch (Steering Pad Switch Assembly) |
When
vehicle-to-vehicle distance control mode is controlling vehicle speed,
the driver can operate the switch to select the vehicle-to-vehicle
distance in 3 stages: long, middle, and short. | |
Stop Light Switch Assembly | Outputs brake pedal depression signals to the ECM. | |
Forward Recognition Camera | Captures the image in front of the vehicle to detect lane markers and objects on the road ahead. | |
Steering Angle Sensor (Spiral Cable with Sensor Sub-assembly) |
Outputs steering angle signals to the millimeter wave radar sensor assembly. | |
Speed Sensor | Outputs wheel speed signals to the skid control ECU. | |
Yaw Rate and Acceleration Sensor (Airbag Sensor Assembly) |
Outputs yaw rate signals to the millimeter wave radar sensor assembly. | |
Skid Control ECU (Brake Actuator Assembly) |
Operates
the brake actuator assembly in accordance with brake request signals
received from the ECM when the dynamic radar cruise control system is in
vehicle-to-vehicle distance control mode. | |
Skid Control Buzzer Assembly | Sounds upon receiving signals from the forward recognition camera. | |
ECM |
- Controls the dynamic radar cruise control system in accordance with
signals received from switches, sensors, and the millimeter wave radar
sensor assembly.
- Stores DTCs if a malfunction is detected in the dynamic radar cruise control system.
| | Throttle Body with Motor Assembly |
Throttle Control Motor | Adjusts the throttle valve opening angle in accordance with signals received from the ECM. | |
Throttle Position Sensor | Outputs the throttle valve opening angle to the ECM. | |
Millimeter Wave Radar Sensor Assembly |
- Detects a preceding vehicle based on signals from the millimeter wave
radar sensor assembly when the dynamic radar cruise control system is in
vehicle-to-vehicle distance control mode. Then, the millimeter wave
radar sensor assembly calculates the acceleration or deceleration
required to achieve the target vehicle-to-vehicle distance, and outputs
request signals to the ECM.
- Stores DTCs if a malfunction is detected in the dynamic radar cruise control system.
- Captures the image in front of the vehicle to detect lane markers and objects on the road ahead.
| | Park/Neutral Position Switch Assembly |
Outputs the shift lever position to the ECM. | |
VSC OFF Switch (Traction Control Switch) |
Outputs VSC off signals to the skid control ECU. | |
Transmission Floor Shift Assembly*1 |
Transmission Control Switch |
While the vehicle is being driven in S mode, outputs "+" (upshift) or "-" (downshift) request signals to the ECM. | |
Column Shift Shift Lever Sub-assembly*2 | |
Trailer Brake Control ECU (Brake Control with Bracket Relay)*3 |
Detects manual trailer brake output slider operations when towing a trailer. |
*1: for Floor Shift Type *2: for Column Shift Type *3: for Trailer Brake Control System
OPERATION OF DYNAMIC RADAR CRUISE CONTROL (a)
Controls performed by the dynamic radar cruise control system in each
control mode (constant speed control mode and vehicle-to-vehicle
distance control mode) are as follows: |
Mode | Outline | |
Constant Speed Control Mode |
Operation
of constant speed control mode is the same as that for the conventional
cruise control system. However, the difference is as follows:
- The lowest possible set speed for the conventional cruise control system
is approximately 40 km/h (25 mph) approximately and 50 km/h (30 mph)
for the dynamic radar cruise control system (constant speed control
mode).
| | Vehicle-to-vehicle Distance Control Mode |
In
vehicle-to-vehicle distance control mode, the system detects a
preceding vehicle and maintains an appropriate vehicle-to-vehicle
distance according to the speed of the preceding vehicle (follow-up
control).
- The driver can operate the vehicle-to-vehicle distance control switch
(steering pad switch assembly) to select the vehicle-to-vehicle distance
in 3 levels: long, middle, or short.
- The mode performs 4 controls: constant speed control, deceleration control, follow-up control, and acceleration control.
| (1) Vehicle-to-vehicle Distance Control Mode: |
Function | Outline | |
Set Control |
- The vehicle speed is stored and control of vehicle speed begins when the
cruise control main switch is pushed to -SET while driving at a speed
of between approximately 50 km/h (30 mph) and 180 km/h (110 mph) with
the dynamic radar cruise control system on.
- When the set speed is stored, the cruise control SET indicator
illuminates and the set speed is displayed on the multi-information
display.
| | Low Speed Limit Control |
The
low speed limit is approximately 40 km/h. If the vehicle speed drops
below the low speed limit, speed control by the dynamic radar cruise
control system is canceled automatically and the set vehicle speed is
kept in memory. | | High Speed Limit Control |
The
highest possible set speed is approximately 180 km/h (110 mph). The
dynamic radar cruise control system cannot be set when the vehicle speed
is over the high speed limit. Also, + (ACCEL)/RES (RESUME) cannot be
used to increase the speed beyond the high speed limit. | |
Constant Speed Control |
The
millimeter wave radar sensor assembly compares the actual vehicle speed
and the stored vehicle speed. When the vehicle speed is less than the
stored vehicle speed, it increases the opening angle of the throttle
valve. | | Follow-up Control |
The
vehicle follows the preceding vehicle while maintaining an appropriate
vehicle-to-vehicle distance according to the speed of the preceding
vehicle. | | Mode Control |
When
the cruise control main switch (ON-OFF button) is pushed and held for
1.5 seconds or more with the dynamic radar cruise control system off,
mode changes to constant speed control mode. | |
+ (ACCEL) Control | When
vehicle-to-vehicle distance control mode is controlling vehicle speed
and the cruise control main switch is pushed to +RES and held, the
stored vehicle speed increases. Once the +RES switch released the
vehicle speed is stored and maintained. Pushing the cruise control main
switch to +RES while following a preceding vehicle using
vehicle-to-vehicle distance control mode does not increase actual
vehicle speed, but changes only the stored vehicle speed. | |
Tap-up Control | When
vehicle-to-vehicle distance control mode is controlling vehicle speed
and the cruise control main switch is tapped to the +RES side (for 0.6
seconds or less), the stored vehicle speed increases by approximately 1
km/h or 1 mph for each time the switch is tapped. | |
- (COAST) Control | When
vehicle-to-vehicle distance control mode is controlling vehicle speed
and the cruise control main switch is pushed to -SET and held, the
stored vehicle speed decrease. Once the -SET switch released the vehicle
speed is stored and maintained. | |
TAP-DOWN Control | When
vehicle-to-vehicle distance control mode is controlling vehicle speed
and the cruise control main switch is tapped to -SET (for 0.6 seconds or
less), the stored vehicle speed decreases by approximately 1 km/h or 1
mph for each time the switch is tapped. | |
Auto Cancel Control | This system has an automatic cancellation function (fail-safe).
 | |
Manual Cancel Control | Performing
any of the following cancels dynamic radar cruise control system
control of vehicle speed (the stored vehicle speed in the ECM is
maintained).
- Depressing the brake pedal.
- Moving the shift lever from D or S to any other position.
- Selecting the S3, S2 or S1 range with the shift lever in S.
- Pulling the cruise control main switch to CANCEL
- Turning the dynamic radar cruise control system off using the cruise
control main switch (ON-OFF button) (the stored vehicle speed in the ECM
is not maintained).
- The brakes are applied with the manual trailer brake output slider.*
| | Other Control Cancellation Conditions |
For details of other cancel controls, refer to the fail-safe chart.
| |
RES (Resume) Control |
- When the vehicle speed is between the low and high speed limits, pushing
the cruise control switch to +RES resumes and maintains the stored
vehicle speed from the time of cancellation.
- If the preceding vehicle moves out of the lane while follow-up control
is operating, the vehicle speed is gradually increased to the set
vehicle speed. At this time, the vehicle speed can be increased by
pushing the cruise control main switch to +RES.
- After the preceding vehicle starts off, a message is displayed to inform
the driver to perform the start-off operation. When the cruise control
main switch is pushed to +RES, follow-up control is resumed and the
vehicle is accelerated up to the set speed.
| | Down Shift Control |
When
driving on an uphill with the dynamic radar cruise control system
controlling vehicle speed, the transmission may downshift from an
overdrive gear. After the downshift, if the system determines that the
uphill inclination has become smaller based on the throttle valve
opening angle, the transmission automatically returns to the overdrive
gear. | | Brake Control |
When
a large amount of deceleration is required while vehicle-to vehicle
distance control mode is controlling vehicle speed, the brake actuator
assembly is operated to apply the brakes. The stop lights illuminate at
this time. | *: for Trailer Brake Control System
(2) Constant Speed Control Mode: |
Function | Outline | |
Constant Speed Control | The
millimeter wave radar sensor assembly compares the actual vehicle speed
and the stored vehicle speed. When the vehicle speed is less than the
stored vehicle speed, it increases the opening angle of the throttle
valve. | | Set Control |
- The vehicle speed is stored and control of vehicle speed begins when the
cruise control main switch is pushed to -SET while driving at a speed
of between approximately 50 km/h (30 mph) and 200 km/h (125 mph) with
the dynamic radar cruise control system on.
- When the set speed is stored, the cruise control SET indicator
illuminates and the set speed is displayed on the multi-information
display.
- The lowest possible set speed is approximately 50 km/h (30 mph).
| | Low Speed Limit Control |
The
low speed limit is approximately 40 km/h. If the vehicle speed drops
below the low speed limit, speed control by the dynamic radar cruise
control system is canceled automatically and the set vehicle speed is
kept in memory. | | High Speed Limit Control |
The
highest possible set speed is approximately 200 km/h (125 mph). The
dynamic radar cruise control system cannot be set when the vehicle speed
is over the high speed limit. Also, + (ACCEL)/RES (RESUME) cannot be
used to increase the speed beyond the high speed limit. | |
+ (ACCEL) Control | When
the dynamic radar cruise control system is controlling vehicle speed
and the cruise control main switch is pushed to +RES and held in that
position, the dynamic radar cruise control system sends a signal to the
ECM to operate the throttle valve motor of the throttle body with motor
assembly to open the throttle valve. Following this, the vehicle speed
is stored and maintained when the cruise control main switch is
released. If the vehicle speed exceeds the high speed limit
(approximately 200 km/h (125 mph)) while the cruise control main switch
is in the +RES position, the highest possible set speed is stored. | |
Tap-up Control | When
the dynamic radar cruise control system is controlling vehicle speed
and the cruise control main switch is tapped to +RES (for approximately
0.6 seconds), the stored vehicle speed increases by approximately 1 km/h
or 1 mph for each time the switch is tapped. When the cruise control
main switch is tapped to +RES and the difference between the current and
stored vehicle speed is more than 5 km/h (3 mph), the stored vehicle
speed will not be changed. | |
- (COAST) Control | When
the dynamic radar cruise control system is controlling vehicle speed
and the cruise control main switch is pushed to -SET and held in that
position, the cruise control system sends a "throttle valve opening
angle 0°" demand signal to the ECM. Following this, the vehicle speed is
stored and maintained when the cruise control main switch is released. HINT:
An actual throttle valve opening angle of 0° is not possible due to factors such as idle speed control. | |
Tap-down Control | When
the dynamic radar cruise control system is controlling vehicle speed
and the cruise control main switch is tapped to -SET (for approximately
0.6 seconds), the stored vehicle speed decreases by approximately 1 km/h
or 1 mph for each time the switch is tapped. When the cruise control
main switch is tapped to -SET and the difference between the current and
stored vehicle speed is more than 5 km/h (3 mph), the current vehicle
speed is stored and speed control is performed. | |
Auto Cancel Control | This system has an automatic cancellation function (fail-safe).
| |
Manual Cancel Control | Performing any of the following cancels dynamic radar cruise control system control of vehicle speed.
- Depressing the brake pedal.
- Moving the shift lever from D or S to any other position.
- Selecting the S3, S2 or S1 range with the shift lever in S.
- Pulling the cruise control main switch to CANCEL.
- Turning the cruise control system off using the cruise control main
switch (ON-OFF button) (the stored vehicle speed in the ECM is not
maintained).
- The brakes are applied with the manual trailer brake output slider.*
| | Other Control Cancellation Conditions |
For details of other cancel controls, refer to the fail-safe chart.
| |
RES (Resume) Control | If
control of vehicle speed by the dynamic radar cruise control system was
canceled due to any of the manual cancel conditions (other than turning
the dynamic radar cruise control system off using the cruise control
main switch (ON-OFF button)), and if the vehicle speed is between the
low and high speed limits, the stored vehicle speed from the time of
cancellation will be resumed and maintained when the cruise control main
switch is pushed to +RES. | *: for Trailer Brake Control System |
