Diagnostic System Check - Cruise Control

Schematic:

CIRCUIT DESCRIPTION
The Cruise Control System is a speed control system that maintains a desired vehicle speed under normal driving conditions. The cruise control system has the capability of the following:
^ Cruise
^ Coast
^ Resume speed
^ Accelerate
^ Raise (Tap-up) the vehicle speed by 1.6 km/h (1 mph)
^ Lower (Tap-down) the vehicle speed by 1.6 km/h (1 mph)

The PCM controls the cruise system. When the cruise control switch is in the ON position and you push the cruise SET/COAST switch, the PCM maintains the current vehicle speed. If the engine load varies, the PCM commands the throttle blade to the appropriate position in order to maintain the desired vehicle speed.

The cruise control system consists of the following components:
^ Powertrain Control Module (PCM)
^ Throttle Actuator Control (TAC) module
^ Throttle body/TAC assembly
^ Cruise control actuator lever

CONDITIONS FOR ENABLING THE CRUISE SYSTEM
^ The cruise switch is in the ON position.
^ The ignition voltage is between 9 and 16 volts.
^ Ignition voltage is present to the cruise actuator lever.
^ The vehicle speed is more than 39 km/h (24 mph).
^ The engine speed is between 550 and 5900 RPM.
^ The clutch or brake pedal is not depressed.
^ The transmission is in a forward gear other than first.
^ The vehicle is not in a traction control event.
^ The engine is not in Engine Coolant Over Temperature-Fuel Disabled mode.
^ The engine has been running for more than 5 seconds.

CONDITIONS FOR DISABLING THE CRUISE SYSTEM
^ The cruise switch is turned to the OFF position.
^ Ignition voltage is interrupted to the cruise actuator lever.
^ The vehicle speed is less than 39 km/h (24 mph).
^ The clutch or brake pedal is depressed.
^ The engine is in Engine Coolant Over Temperature-Fuel Disabled mode.
^ The transmission is placed into neutral.
^ A problem with the clutch or brake pedal switches or circuits that the PCM module interprets as the pedal is applied.

DIAGNOSTIC AIDS
Use the scan tool in order to monitor the Cruise Disengage History. This parameter lists the last 8 cruise disengage events. Refer to Cruise Disengage History table for a description of each condition.

The cruise control system disables for the current ignition cycle if an intermittent condition exists and DTC P0567 or DTC P0568 sets.