CRUISE CONTROL SYSTEM

FUNCTION OF MAIN COMPONENTS

1. The main components in the cruise control system have the following functions:

   Component		Function
   Cruise Control Main Switch	ON-OFF Button	Turns the power to the cruise control system on and off.
   	CANCEL Switch	A cancel signal can be output to the hybrid vehicle control ECU through the operation of this switch.
   	+RES Switch	The accelerate function and resuming of a preset speed can be performed by operating this switch. A signal is output to the hybrid vehicle control ECU when this switch is operated.
   	-SET Switch	The decelerate function and vehicle speed setting signals are output to the hybrid vehicle control ECU due to operation of this switch.
   Hybrid Vehicle Control ECU		Controls all functions of the cruise control system in accordance with the signals from switches, sensors and ECUs.
   MG ECU		Built into the inverter with converter assembly. Controls the motive force of the MG2 in accordance with signals from the hybrid vehicle control ECU.
   ECM		Actuates the throttle control motor in accordance with the signals from the hybrid vehicle control ECU.
   Skid Control ECU		Transmits the wheel speed signal and VSC operation signal to the hybrid vehicle control ECU.
   Combination Meter Assembly	Cruise Main Indicator Light	Based on a cruise control indicator operation signal sent by the hybrid vehicle control ECU, the combination meter assembly illuminates the cruise main indicator light in green when the cruise control system has been turned on using the ON-OFF button on the cruise control main switch. Based on a cruise control indicator operation signal sent by the hybrid vehicle control ECU, the combination meter assembly illuminates the cruise main indicator light in yellow if a malfunction occurs in the cruise control system.
   	Cruise SET Indicator Light	Illuminates when the vehicle speed is set.
   MG2		Generates the motive force for the wheels.
   Throttle Control Motor		Adjusts the throttle valve opening angle in accordance with signals from the ECM.
   Throttle Position Sensor		Transmits the throttle valve position information to the ECM.
   Front Speed Sensor LH/RH, Rear Speed Sensor LH/RH		Detects the wheel speed of each of 4 wheels.
   Accelerator Pedal Sensor Assembly		Detects the accelerator pedal depression degree and outputs it to the hybrid vehicle control ECU.
   Shift Lever Position Sensor		Detects the shift position and transmits signals to the hybrid vehicle control ECU.
   Stop Light Switch Assembly		Detects the brake pedal being depressed and transmits its signal to the hybrid vehicle control ECU.

FUNCTION

1. The cruise control has the following control functions.

   Function	Outline
   Constant Speed Control	The hybrid vehicle control ECU compares the actual vehicle speed with the set speed. If the vehicle speed is higher than the set speed, the hybrid vehicle control ECU calculates optimal motive forces for the engine and MG2, and decelerates by adjusting the respective motive forces. If the vehicle speed is lower than the set speed, the hybrid vehicle control ECU calculates optimal motive forces for the engine and MG2, and accelerates by adjusting the respective motive forces.
   Set Control	When this system fulfils the following conditions, and the cruise control main switch is moved to the -SET side and released, the hybrid vehicle control ECU stores the vehicle speed and illuminates the cruise SET indicator light on the combination meter assembly and maintains the vehicle constantly at that speed. ON-OFF button on the cruise control main switch is pressed. The vehicle is running at an approximate speed of between 40 km/h (25 mph) and 200 km/h (125 mph).
   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 cannot be set below that speed. If the vehicle speed drops below that speed while running in the cruise control, the cruise control will be cancelled automatically. However the set speed is kept in memory.
   COAST (-) Switch Control	When the cruise control main switch is held to the -SET side, the vehicle speed and the set vehicle speed change as follows: The vehicle will decelerate. The set vehicle speed will change to the speed that the vehicle is traveling at when the COAST switch (-SET side operation) is released.
   Tap Down Control	When the cruise control main switch is moved momentarily (approximately 0.6 seconds or less) to the -SET side, the vehicle speed and the set vehicle speed change as follows: The vehicle will decelerate in increments of approximately 1.6 km/h (1 mph) each time the switch is moved. However, if the difference between the actual vehicle speed and the set vehicle speed is greater than 5 km/h (3 mph), the set vehicle speed will change to the speed at which the vehicle was traveling at when the switch was pushed.
   ACC (+) Switch Control	When the cruise control main switch is held to the +RES side, the vehicle speed and the set vehicle speed change as follows: The vehicle will accelerate. The set vehicle speed will change to the speed at which the vehicle was being driven at the time the switch was released.
   Tap Up Control	When the cruise control main switch is moved momentarily (approximately 0.6 seconds or less) to the +RES side, the vehicle speed and the set vehicle speed change as follows: The vehicle will accelerate in increments of approximately 1.6 km/h (1 mph) each time the switch is moved. However, if the difference between the actual vehicle speed and the set vehicle speed is greater than 5 km/h (3 mph), the set vehicle speed will not change.
   RES Switch Control	If the cruise control is canceled for any reason other than a malfunction (except cancellation by operating the ON-OFF button on the cruise control main switch) and the vehicle speed is more than the low speed limit, the vehicle can be returned to the speed which was before the cancellation of cruise operation by moving the cruise control main switch to the +RES side. The cruise control mode can be resumed even if the vehicle speed drops below the low speed limit, because the speed in the memory has not been cleared.
   Manual Cancel Control	If any of the following signals are sent to the hybrid vehicle control ECU, the cruise control is cancelled accordingly. Stop light switch assembly on signal (The brake pedal is depressed). D position circuit in the shift lever position sensor off signal (The shift lever is moved from D to N or B). CANCEL switch on signal (The cruise control main switch is moved to the CANCEL side). Cruise control main switch (ON-OFF button) off signal VSC operation
   Automatic Cancel Control	If the following condition occurs during cruise control operation, the speed that is set in the memory is cleared and the cruise control is cancelled. Stop light switch assembly open or short circuit Furthermore, the cruise main indicator light will illuminate in yellow until the ON-OFF button on the cruise control main switch is used to turn the system off. Also, the operation of the cruise control will be disabled until the ON-OFF button is turned on again.
   	If the following condition occurs during cruise control operation, the speed that is set in the memory is cleared and the cruise control is cancelled. Malfunction in the hybrid system Furthermore, the operation of the cruise control will be disabled until the ON-OFF button is turned on again.
   	If any of the following conditions occur during cruise control operation, the speed that is set in the memory is cleared and the cruise control is cancelled. Stop light switch assembly input signal is abnormal. Cancel circuit malfunction Brake control system malfunction Communication malfunction between the skid control ECU and hybrid vehicle control ECU Furthermore, the cruise main indicator light will illuminate in yellow until the ON-OFF button on the cruise control main switch is used to turn the system off. Also, the operation of the cruise control will be disabled until the ignition switch is turned off.
   	If the following condition occurs during cruise control operation, the speed that is set in the memory is cleared and the cruise control is cancelled. Vehicle speed decreases by 16 km/h (10 mph) or more below the speed at which the cruise control was set.
   	If the following condition occurs during cruise control operation, the cruise control is cancelled. Vehicle speed is below the low speed limit (approximately 40 km/h [25 mph]).

CONSTRUCTION

OPERATION

1. Combination Meter Assembly

   
   

   1. The combination meter assembly provides a cruise main indicator light and cruise SET indicator light to indicate in the cruise control system.

      Condition
      Set Standby	Illuminates (Green)	-
      Being Controlled	Illuminates (Green)	Illuminates
      System Malfunction	Illuminates (Yellow)	-

DIAGNOSIS

1. If a malfunction occurs in the cruise control system during cruise control operation, the hybrid vehicle control ECU automatically cancels control and illuminates the cruise main indicator light in yellow to inform the driver of the malfunction. At this time, the hybrid vehicle control ECU stores the malfunction in the form of a 5-digit Diagnostic Trouble Code (DTC).

2. The 5-digit DTC can be read by connecting the Global TechStream (GTS) to DLC3. For details, refer to the Repair Manual.