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Home >> Toyota >> 2007 >> Avalon XLS >> Repair and Diagnosis >> Electrical >> Body Electrical >> OEM System Circuits >> Dynamic Radar Cruise Control >> System Outline

System Outline

The radar cruise control system allows you to drive at a selected cruising speed, maintaining an appropriate vehicle-to-vehicle distance using the laser radar sensor, the steering sensor and the yaw rate sensor. The laser radar sensor detects the reflection of the vehicle ahead in your lane.

  1. Setting Operation 

    < The vehicle-to-vehicle distance control mode >

    While the ON-OFF SW is ON (The power indicator light is turned on), bring the vehicle to the desired speed, press the control lever downward in the "- SET" direction and release it. This sets the vehicle at that speed from the lower limit of the preset speed about 45 km/h (28 mph) to the upper limit of the preset speed about 135 km/h (85 mph). However, the vehicle speed is faster than 135 km/h (85 mph), the preset spped is the upper limit of the preset speed.

    < The conventional cruise control mode >

    While the ON-OFF SW is ON (The power indicator light is turned on), bring the vehicle to the desired speed, press the control lever downward in the "- SET" direction and release it. This sets the vehicle at that speed. It is possible to set at that speed between lower speed limit and higher speed limit.

  2. Resetting to a Speed 

    < The vehicle-to-vehicle distance control mode >

    1. Resetting to a lower speed

      The set speed can be decreased 5 mph (For USA) or 5 km/h (For Canada) each time by pressing the control lever downward in the "- SET" direction quickly within 0.5 seconds.

      And while the cruise control is on and the control lever is held downward in the "- SET" direction, the preset speed will decrease every 5 mph (For USA) or 5 km/h (For Canada). But you cannot decrease lower than the lower limit of the preset speed about 27 mph (For USA) or 43 km/h (For Canada). If the preset speed is changed, the vehicle speed will be gradually decreased to the preset speed. (In the other case, perhaps the vehicle speed will be increase.)

    2. Resetting to a faster speed

      *The set speed can be increased 5 mph (For USA) or 5 km/h (For Canada) each time by pressing the control lever upward in the "+ RES" direction quickly within 0.5 seconds.

      And while the cruise control is on and the control lever is held upward in the "+ RES" direction, the preset speed will increase every 5 mph (For USA) or 5 km/h (For Canada). But you cannot increase faster than the upper limit of the preset speed. If the preset speed is changed, the vehicle speed will be constantly increased to the preset speed. (In the other case, perhaps the vehicle speed will be decrease.)

      *When your vehicle follow up cruise function, if press the control lever upward in the "+ RES" direction, the vehicle speed will not be increased and the preset speed will be changed only.

    < The conventional cruise control mode >

    1. Deceleration

      *While the cruise control is on and the control lever is held downward in the "- SET" direction, the vehicle speed will gradually decrease. When you release it, this sets the vehicle speed at that speed. If the control lever is released when the vehicle speed exceeds the upper limit of the preset speed traveling downhill while you are pressing the control lever downward, the system will memorize the upper limit of the preset speed as a preset speed.

      *When the difference between the actual vehicle speed and the set speed is less than 5 km/h (3 mph), the set speed can be decreased 1.6 km/h (1 mph) each time by pressing the control lever downward in the "- SET" direction quickly within 0.5 seconds. But if the control lever is released when the difference between the actual vehicle speed an the set speed is more than 5 km/h (3 mph), this sets the vehicle speed at that speed.

    2. Acceleration

      *While the cruise control is on and the control lever is held upward in the "+ RES" direction, the vehicle speed will constantly increase. When you release it, this sets the vehicle speed at that speed. If the vehicle speed exceeds the upper limit of the preset speed while you are pressing the control lever downward, the system will cruise at the upper limit of the preset speed. And if the control lever is released, this sets the vehicle speed at that speed.

      *When the difference between the actual vehicle speed and the set speed is less than 5 km/h (3 mph), the set speed can be increased 1.6 km/h (1 mph) each time by pressing the control lever upward in the "+ RES" direction quickly within 0.5 seconds. But if the control lever is released when the difference between the actual vehicle speed and the set speed is more than 5 km/h (3 mph), this sets the vehicle speed at that speed.

      *If you are pressing the control lever downward and released when the vehicle speed is increased by pressing the acceleration pedal, the system will memorize the preset speed at that speed. But if you operate the control lever downward at the upper limit of the set speed, you cannot set the preset speed.

  3. The Lower Limit of the Preset Speed 

    *This is the lower limit of the preset speed of the followings. This is a difference of the lower limit of the canceled speed.

    *For USA: about 27 mph

    *For Canada: about 43 km/h

    *When the vehicle speed is less than the lower limit of the preset speed, you cannot change the preset speed.

  4. The Lower Limit of the Canceled Speed 

    *This is the lower limit of the canceled speed about 40 km/h (25 mph). And if the vehicle speed falls below about 40 km/h (25 mph), the preset speed will be automatically cancelled. In the vehicle-to-vehicle distance control mode the preset speed will be stored, and in the conventional cruise control mode the preset speed will not be stored.

  5. The Upper Limit of the Preset Speed 

    This is the upper limit of the preset speed of the followings.

    *For USA: about 85 mph

    *For Canada: about 139 km/h

  6. The Upper Limit of the Possible Speed to Use the Cruise Control (Only for the Conventional Cruise Control Mode) 

    This is the upper limit of the possible speed to use the cruise control.

    *For USA: about 125 mph

    *For Canada: about 200 km/h

  7. Resuming the Preset Speed 

    *If the preset speed has been canceled, when you push the lever up in the "+ RES" direction while "RADAR READY" shows up on the instrument cluster and at a vehicle speed of about more than the lower limit of the canceled speed, the speed set prior to cancellation will be restored. However, once the vehicle speed falls below about 40 km/h (25 mph), the preset speed will not be resumed at the conventional cruise control mode.

    *During follow-up cruising, if there are no vehicles running ahead because they have changed lanes, your vehicle will accelerate gradually up to the preset speed. At this time, pushing the control lever upward in the "+ RES" direction will quickly speed up your vehicle in the vehicle-to-vehicle distance control mode.

  8. Shift Down Control 

    While the cruise control is on, there is a possible case of the cancelled over drive on a climbing hill. If the system judge the end of a climbing hill after the cancelled over drive, the vehicle will return the over drive mode after the returned over drive timer.

  9. Canceling the Preset Speed 

    If the following signals is put in the micro computer when the cruise control is on, this system will be cancel. (The preset speed has been stored.)

    1. Depressing the brake pedal. (Input the stop light switch signal)
    2. Turn the "D" position circuit in neutral start switch on and then off.

      When the transmission is changed from "D" or "N", cancel the preset speed.

      At transmission "S", when the transmission is changed from "5" or "4" to "N", "3", "2" and "1", cancel the preset speed.

    3. Pulling the control lever in the "CANCEL" direction.
    4. The ON-OFF SW is OFF. (In this case, the set speed is not stored.)
    5. VSC system is activated.
  10. Automatically Cancel 
    1. If any of the following conditions then occurs, the preset speed automatically cancels out and the cruise control system will be canceled. And then, the "CRUISE" indicator light in the instrument cluster flashes until the ON-OFF SW will be turned off, the master warning light comes on and the warning tone sounds, and the warning code will appear on the display. The system cannot be entered until the ON-OFF SW will be turned on again.
      1. The vehicle speed sensor is malfunction.
      2. The parts of the electronic throttle are malfunction.
      3. The stop light switch circuits is open or short.
    2. If any of the following conditions then occurs, the preset speed automatically cancels out and the cruise control system will be canceled. And then, the "CRUISE" indicator light in the instrument cluster flashes until the ON-OFF SW will be turned off, the master warning light comes on and the warning tone sounds, and the warning code will appear on the display. The system cannot be entered until the ON-OFF SW will be turned on again.
      1. The laser radar sensor is malfunction.
      2. Improper aiming of laser radar sensor beam axis.
      3. The radar cruise control system is malfunction except above A), B).
    3. If any of the following conditions then occurs, the preset speed automatically cancels out and the cruise control system will be canceled. And then, the "CRUISE" indicator light in the instrument cluster flashes until the ON-OFF SW will be turned off, the master warning light comes on and the warning tone sounds, and the warning code will appear on the display. The system cannot be entered until it will be back the normal condition from above A)~E) (It is possible to resume.) and the ON-OFF SW will be turned on again.
      1. The laser radar sensor is dirtied.
      2. The wipers are operated at high or low speeds (Including high and low speed operations with the wiper lever in the "AUTO" position.)
      3. Direct the strong light of sunlight, etc. from the front.
      4. It is determined that it is difficult to make a measurement because of bad weather (Such as rainy, foggy, or snowy weather).
    4. If any of the following conditions then occurs, the preset speed will be automatically cancelled out. However, at the vehicle-to-vehicle distance control mode the preset speed will be stored.
      1. The vehicle speed falls below about 40 km/h (25 mph).
      2. The vehicle speed drops 16 km/h (10 mph) below preset speed. (Only for the conventional cruise control mode)
  11. Changing the Radar Cruise Control Mode 

    When you push the ON-OFF SW, the vehicle-to-vehicle distance mode is activated. To change to the conventional (Fixed speed) cruise control mode, push the lever in the "MODE" direction for longer than about 1 second.

    However, once the vehicle-to-vehicle distance mode activates and is used, it cannot be changed to the conventional cruise control mode using the above operation.

    To change the mode, turn the ON-OFF SW off and then on. Next push the lever in the "MODE" direction for longer than about 1 second.

    If the system malfunction then occurs, turn the engine off and then it on again. Next above operation will be changed to it.



The cruise control system is a constant vehicle speed controller which controls the opening angle of the engine throttle valve by the SW, and allows driving at a constant speed without depressing the accelerator pedal.

Set Operation 

When the ON-OFF SW is turned on, the systems starts preparations for cruise control and turns on the indicator light in the combination meter.

Set Speed Control 

When the - SET SW is operated with the ON-OFF SW turned on during driving, the speed is controlled at a constant speed.

Coast Control 

When the - SET SW is kept turned on during cruise control driving, the engine control module controls the throttle valve to decelerate the vehicle speed.

Every time the - SET SW is turned on instantaneously, the vehicle speed is decelerated by approx. 1.6 km/h.

Accel Control 

When the + RES SW is kept turned on during cruise control driving, the engine control module controls the throttle valve to accelerate the vehicle speed.

Every time the + RES SW is turned on instantaneously, the vehicle speed is accelerated by approx. 1.6 km/h.

Resume Control 

If the vehicle speed is within the low speed limit (Approx. 40 km/h, 25 mph) when canceling the cruise control, operation of the + RES SW accelerates the vehicle speed and resumes the level before canceling the cruise control.

Manual Cancel Mechanism 

If any one of the following signals is input during cruise control driving, the cruise control is canceled.

*The stop light SW is on

*The CANCEL SW is turned on

*The ON-OFF SW is turned off

*When switching from ON to OFF of "D" position circuit in neutral start switch.

When the transmission is shifted from "D" to "N".

Auto Cancel Function 

If any of the following conditions are detected, the cruise control is canceled:

*Failure in the stop light SW wiring

*Abnormality in the vehicle speed signal

*Malfunction in the electronically controlled throttle parts

*When the vehicle speed gets slower than the low speed limit.

*When the vehicle speed falls to 16 km/h less than the set speed.

Overdrive Function 

The overdrive may be canceled if the vehicle travels on a upward slope during cruise control driving. When the throttle opening information indicates the hill climbing is finished after the overdrive is canceled, the vehicle returns to overdrive mode again as the overdrive return timer is completed.