Cruise Control is a system in which the ECU automatically controls the vehicle to achieve and maintain a speed set by the driver. To do this the ECU controls the throttle plate in the vehicles electronic throttle body.
Cruise Control Minimum Requirements
In order for the ECU to correctly perform Cruise Control safely the following minimum requirements must be met:
·Electronic Throttle - The engine must have an electronic throttle system that is controlled by the ECU, correctly tuned, and has no faults.
·Driving Wheel Speed - The ECU must have a Driving Speed Source correctly setup and working.
·Cruise On Switch - The system must have a switch used to enable the Cruise Control system.
·Cruise Set Switch - The system must have a switch used to activate the Cruise Control system at the current driving wheel speed.
·Brake Switch - The system must have a switch that activates when the brake pedal is pressed. The ECU must know when this switch is activated either by being directly wired to one of the ECUs Digital Inputs or via one of the ECUs CAN modules. If both Brake NC and Brake NO have no source Cruise Control will not be enabled. If either Brake switch becomes active while Cruise Control is active Cruise Control will be disabled and the status changed to enabled.
·Clutch Switch - The clutch switch must be set up and working if the vehicle is manual. This switch will disable the cruise control when it becomes active.
WARNING
Cruise Control, if incorrectly configured, could lead to serious injury or major vehicle damage. For minimum safe operation you MUST make sure that a brake switch is connected to the ECU and operating correctly. DO NOT attempt to configure any part of the Cruise Control system if you are at all unsure or do not have sufficient experience to do so.
WARNING
Every effort has been made to ensure that the Cruise Control system is reliable and safe. However, incorrect installation, wiring and setup can cause unexpected operation. If at any stage you are unsure, immediately contact your Link dealer for advice. Link provides Cruise Control functionality 'as is' and accepts no responsibility for the use of Cruise Control or any consequential damage that may directly or indirectly arise from the use of Cruise Control.
Cruise Control Settings
Warning: Do NOT adjust Cruise Control settings without fully understanding their function. It is not possible to tune Cruise Control without knowledge of PID control algorithms. For this reason, Cruise Control tuning should be left to experienced tuners only.
The following settings exist for configuring Cruise Control:
Must be set to something other than OFF in order to configure Cruise Control. Currently only speed control is available.
Used to select the type of cruise switch input being used.
·Digital - Four separate digital inputs - On, Set/Coast, Resume/Accel and Cancel.
·Analog - One Analog Input with the four inputs being definable voltages.
·Subaru Cruise Switch - Three digital inputs - On, Switch A and Switch B.
This setting allows the user to set an Auxiliary output that will be active when Cruise Control is Active.
This setting allows the user to set an Auxiliary output that will be active when Cruise Control is Active or Enabled.
Sets the cruise control power (On) switch to be a Momentary or Toggle switch.
The minimum speed to which the Cruise Set Speed can be set. If the Cruise Control Status is Active and the Driving wheel speed drops below the Min Speed Lockout the Cruise Control Status will change to Enabled.
The maximum speed to which the Cruise Set Speed can be set. If the Cruise Control Status is Active and the Driving wheel speed climbs above the Max Speed Lockout the Cruise Control Status will change to Enabled.
The maximum rate at which the Cruise Control system will allow the vehicle to accelerate to achieve the Cruise Set Speed.
Adjusts the Proportional Gain of the Cruise Control's PID algorithm. Increasing this number increases the proportional gain, decreasing this number decreases the proportional gain.
Adjusts the Integral Gain of the Cruise Control's PID algorithm. Increasing this number increases the integral gain, decreasing this number decreases the integral gain.
Adjusts the Derivative Gain of the Cruise Control's PID algorithm. Increasing this number increases the derivative gain, decreasing this number decreases the derivative gain.
Digital:
·Cruise On Switch - Used to select the switched input that controls the Cruise On functionality. Enables and disables Cruise Control.
·Cruise Set Switch - Used to select the switched input that controls the Cruise Set functionality. Activates Cruise and sets the cruise speed or reduces the set speed depending on conditions (Set/Coast functionality).
·Cruise Resume Switch - Used to select the switched input that controls the Cruise Resume functionality. Activates cruise at the previous set speed or increases the current set speed depending on conditions (Resume/Accel functionality).
·Cruise Cancel Switch - Used to select the switched input that controls the Cruise Cancel functionality. Disables Cruise Control (changes from Active to Enabled), Brake NC, Brake NO and the Clutch switch also disable Cruise Control in the same manner when active.
·Analog Cruise Input - Used to select the analog input that the cruise switches are connected to.
·On Switch Voltage - Used to tell the ECU what the input voltage is when the On Switch is active. Enables and disables Cruise Control.
·Set Switch Voltage - Used to tell the ECU what the input voltage is when the Set Switch is active. Activates Cruise and sets the cruise speed or reduces the set speed depending on conditions (Set/Coast functionality).
·Resume Switch Voltage - Used to tell the ECU what the input voltage is when the Resume Switch is active. Activates cruise at the previous set speed or increases the current set speed depending on conditions (Resume/Accel functionality).
·Cancel Switch Voltage - Used to tell the ECU what the input voltage is when the Cancel Switch is active. Disables Cruise Control (changes from Active to Enabled), Brake NC, Brake NO and the Clutch switch also disable Cruise Control in the same manner when active.
·Cruise Switch Voltage Tolerance - Used to set the tolerance for each of the switch voltages, for example a tolerance of 0.3V means that the switch is considered to be active if the voltage is within plus or minus 0.3V of the specified switch voltage.
Subaru Cruise Switch:
·Cruise On Switch - Used to select the switched input that controls the Cruise On functionality. Enables and disables Cruise Control.
·Cruise SwA - Used to select the switched input that controls the Cruise SwA functionality.
·Cruise SwB - Used to select the switched input that controls the Cruise SwB functionality.
The logic for SwA and SwB is:
·SwA and SwB - Cancel, disables Cruise Control (changes from Active to Enabled), Brake NC, Brake NO and the Clutch switch also disable Cruise Control in the same manner when active.
·SwA and not SwB - Set, activates Cruise and sets the cruise speed or reduces the set speed depending on conditions (Set/Coast functionality).
·SwB and not SwA - Resume, activates cruise at the previous set speed or increases the current set speed depending on conditions (Resume/Accel functionality).