Cruise control is a speed control system that maintains a desired vehicle speed under normal driving conditions at speeds above 40 km/h (25 mph). Steep grades may cause variations in the selected vehicle speeds.

The following are the main components of the cruise control system:

The Cruise Control System will engage and adjust vehicle speeds, based on the activation of the following cruise control switches:

The powertrain control module (PCM) monitors the cruise control set/coast and resume/accel switch signal circuit in order to determine when to capture and maintain the vehicle speed. The PCM monitors the vehicle speed sensor signal circuit in order to determine the vehicle speed. The PCM uses the throttle actuator control (TAC) motor in order control the vehicle speed. For further information on the TAC System, refer to Throttle Actuator Control (TAC) System Description in Engine Controls - 2.8L (LK5) or to Throttle Actuator Control (TAC) System Description in Engine Controls - 3.5L (L52).

Ignition voltage is supplied to the cruise control switch from the 10 ampere CRUISE fuse via the ignition 1 voltage circuit. The cruise control switches are arranged in a resistive ladder, with each cruise control function switch having a different resistance value. The PCM detects a specific voltage value that is associated with the cruise control function switch being activated. When the normally open cruise control On/Off switch is turned ON, the switch closes and the PCM detects a predetermined voltage signal on the cruise control switch signal circuit indicating that the On/Off switch is active. Similarly, when the normally open set/coast switch or the normally open resume/accel switch are activated, the PCM detects the pre determined voltage signal on the cruise control set/coast and resume/accel switch signal circuit. To engage the Cruise Control System, press the cruise On/Off switch ON and momentarily press the set/coast switch. The PCM will confirm that the cruise control criteria has been met. The PCM will record the vehicle speed and send a class 2 message to the instrument panel cluster (IPC) in order to illuminate the cruise control indicator. The set/coast switch and the resume/accel switch will remain inactive when the PCM has not received the predetermined voltage signal from the On/Off switch. Pressing the accelerator pedal, while the Cruise Control System is engaged, will allow the driver to override the Cruise Control System in order to accelerate the vehicle beyond the current set vehicle speed. When the accelerator pedal is released, the vehicle will decelerate and resume the current set vehicle speed. The driver can also override the current set vehicle speed via the set/coast switch and the resume/accel switch. When the Cruise Control System is engaged, pressing and holding the set/coast switch will allow the vehicle to decelerate from the current set vehicle speed without deactivating the Cruise Control System. When the set/coast switch is released, the PCM will record the vehicle speed and maintain the vehicle speed as the new set vehicle speed. When the Cruise Control System is engaged, momentarily pressing the set/coast switch will allow the vehicle to decelerate at 1.6 km/h (1 mph) increments for each time that the set/coast switch is momentarily pressed, with a minimum vehicle speed of 37 km/h (23 mph). Activating and holding the resume/accel switch, when the Cruise Control System is engaged, will allow the vehicle to accelerate to a greater vehicle speed than the current set vehicle speed. When the resume/accel switch is released, the PCM will record the vehicle speed and maintain the vehicle speed as the new set vehicle speed. When the Cruise Control System is engaged, momentarily activating the resume/accel switch will allow the vehicle to accelerate at 1.6 km/h (1 mph) increments for each time that the resume/accel switch is momentarily activated, with the maximum acceleration total of 16 km/h (10 mph) over the current set vehicle speed. Momentarily activating the resume/accel switch, after the Cruise Control System has been disengaged by pressing the brake pedal, will recall the previous set vehicle speed that is recorded in the PCM.

The powertrain control module (PCM) disengages the cruise control operation based on the signals from the following switches:

The TCC brake/cruise release switch and the stop lamp switch are mounted on the brake pedal bracket. When the brake pedal is applied, the normally closed TCC brake/cruise release switch opens and the normally open stop lamp switch closes. The PCM detects a low signal voltage on the TCC brake/cruise release switch signal circuit and a high signal voltage on the stop lamp switch signal circuit. When the clutch pedal is applied, the normally closed clutch release switch opens and the PCM detects zero voltage on the CCP switch signal circuit. The vehicle speed stored in the memory of the PCM will be erased when the cruise control On/Off button is turned OFF, or the ignition switch is turned OFF.

The Cruise Control System will disengage when the PCM detects that a driver override function has been active for approximately 60 seconds.

When the Cruise Control System is disengaged, the PCM sends a class 2 message to the instrument panel cluster (IPC) in order to deactivate the cruise control indicator.

The powertrain control module (PCM) inhibits the cruise control operation when any of the following conditions exist: