SYSTEM DESCRIPTION GENERAL The
cruise control system is controlled by the ECM, and vehicle speed
control is performed using the throttle body with motor assembly. The
ECM controls the following functions: ON-OFF, - (COAST)/SET, +
(ACCEL)/RES (RESUME), CANCEL, vehicle speed operation and shift down
control.
- The ECM compares the vehicle speed from the speed sensors with the
stored vehicle speed set using the cruise control main switch. The ECM
increases the opening angle of the throttle valve when the actual
vehicle speed is below the stored vehicle speed, and decreases the
opening angle of the throttle body when the actual vehicle speed is more
than the stored vehicle speed.
- The ECM receives signals such as ON-OFF, - (COAST)/SET, + (ACCEL)/RES
(RESUME), and CANCEL signals from the cruise control main switch.
- The ECM illuminates the cruise control indicator in the combination
meter assembly when the cruise control system is turned on using the
cruise control main switch (ON-OFF button).
- The ECM turns off the cruise control indicator in the combination meter
assembly and displays a warning message if a malfunction is detected
when the cruise control system is controlling vehicle speed.
- The ECM illuminates the cruise control SET indicator in the combination
meter assembly when vehicle speed control begins after the cruise
control main switch is pushed to -SET while driving. Also, the ECM
displays the current set speed on the multi-information display when the
cruise control main switch is pushed to +RES or -SET.
|
*1 |
Cruise Control Indicator |
|
*2 |
Cruise Control SET Indicator |
FUNCTION OF MAIN COMPONENTS (a) The main components of the cruise control system have the following functions: |
Component | Function | |
Cruise Control Main Switch | ON-OFF Button |
Turns the cruise control system on and off. | |
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. | |
Skid Control ECU (Brake Actuator Assembly) |
- Sends VSC operation signals to the ECM.
- Sends TRAC operation signals to the ECM.
- Sends signals such as wheel speed and estimated vehicle acceleration signals to the ECM.
| | ECM |
Controls all functions of the cruise control system in accordance with the signals received from switches, sensors and ECUs. | |
Combination Meter Assembly | Cruise Control Indicator |
- Illuminates based on signals from the ECM when the cruise control system
is turned on using the cruise control main switch (ON-OFF button).
- Turns off based on signals from the ECM when a malfunction is detected in the cruise control system.
| | Cruise Control SET Indicator |
Illuminates when the vehicle speed is set. | |
Multi-information Display |
- Displays warning messages to alert the driver.
- Displays the current set speed.
| | Throttle with Motor Body 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. | |
Speed Sensor | Outputs wheel speed signals to the skid control ECU. | |
Accelerator Pedal Sensor Assembly | Outputs accelerator pedal depression angle to the ECM. | |
Park/Neutral Position Switch Assembly |
Outputs the shift lever position to the ECM. | |
VSC OFF Switch | Outputs VSC off signals to the skid control ECU. | |
Stop Light Switch Assembly | Outputs brake pedal depressed signals to the ECM. | |
Trailer Brake Control ECU (Brake Control with Bracket Relay)* |
Detects manual trailer brake output slider operations when towing a trailer. |
*: for Trailer Brake Control System OPERATION OF CRUISE CONTROL
(a) The cruise control system has the following control functions: |
Function | Outline | |
Constant Speed Control | The
ECM compares the actual vehicle speed and the set speed and if the
vehicle speed is less than the set speed, it uses the throttle control
motor to increase the throttle valve opening angle. | |
Set Control | The
vehicle speed is stored and speed control is performed when the cruise
control main switch is pushed to -SET while driving with the cruise
control system on and the vehicle speed is within the set speed range.
The current set speed is displayed on the multi-information display when
the cruise control main switch is pushed to +RES or -SET. | |
Low Speed Limit Control | The
low speed limit is the lowest speed that cruise control can be set at
and it is designed to be approximately 40 km/h (25 mph). The cruise
control system cannot be set below that speed. If the vehicle speed
drops below that speed while the cruise control is operating, speed
control by the cruise control system will be canceled automatically.
However, the set speed is kept in memory. | |
High Speed Limit Control | The
highest possible set speed is approximately 200 km/h (125 mph). The
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. | |
- (COAST) Control | When
the 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. | |
Tap-down Control | When
the 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. | | + (ACCEL) Control |
When
the cruise control system is controlling vehicle speed and the cruise
control main switch is pushed to +RES and held in that position, the
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. | |
Tap-up Control | When
the 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 1.0 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. | | RES (Resume) Control |
If
control of vehicle speed by the cruise control system was canceled due
to any of the manual cancel conditions (other than turning the 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. | | Shift Down Control |
When
the vehicle is traveling uphill using cruise control, automatic
transmission control may cause the transmission to shift down. During
shift down control, when the end of uphill travel is determined, the
transmission will shift up after a certain period of time. When the
transmission shifts down during the accelerator control or the resume
control, the transmission will shift up after the accelerator control or
the resume control ends. | | Manual Cancel Control |
Performing
any of the following cancels the 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 3rd, 2nd or 1st range with the shift position 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.*
| | Automatic Cancel Control |
This system has an automatic cancellation function (fail-safe).
 |
*: for Trailer Brake Control System |
