Cruise Control Description and Operation 4.3L

Cruise control is a speed control system that maintains a desired vehicle speed under normal driving conditions at vehicle 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:

Cruise Control Engaged

The cruise control system will engage and adjust vehicle speed based on the activation of the following cruise control switches:

The cruise control switches are located on the multifunction/turn signal lever.

The cruise control module monitors the signal circuits of the cruise control switches in order to determine when to capture and maintain the selected vehicle speed. The cruise control module receives the vehicle speed signal from the PCM, via the vehicle speed signal circuit. The cruise control module is an electronic controller and an electric stepper motor. The electric controller monitors the vehicle speed and operates the electric stepper motor. The electric stepper motor moves a strap that is attached to the cruise control cable in order to move the throttle linkage.

Ignition positive voltage is supplied from the 10-ampere CRUISE fuse, to the cruise control switch and to the cruise control module via the ignition 3 voltage circuit. When the normally open cruise control On/Off switch is turned On, the switch closes and the cruise control module detects a high signal voltage on the cruise on switch signal circuit. When the normally open Set/Coast switched is pressed, the switch closes and the cruise control module detects a high signal voltage on the set/coast signal circuit. To engage the cruise control system, the On/Off switch must be On and the Set button momentarily pressed. The cruise control module grounds the cruise control engaged signal circuit to the PCM. The PCM will confirm that the cruise control enable criteria has been met. The cruise control module will record the selected vehicle speed. The PCM sends a class 2 message to the instrument panel cluster in order to illuminate the cruise control indicator. 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 cruise control module 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 is momentarily pressed, with a minimum vehicle speed of 37 km/h (23 mph). When the normally open Resume/Accel switch is activated, the switch closes and the cruise control module detects a high signal voltage on the cruise control resume/accel switch signal circuit. 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 cruise control module 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 cruise control module.

Cruise Control Disengaged

The cruise control module disengages the cruise control operation based on the signals from the following switches:

The stop lamp switch, the TCC brake switch, and the CPP switch are used to disengage the cruise control system. The stop lamp and the TCC brake switch are incorporated into an assembly and are mounted to the brake pedal bracket. When the brake pedal is depressed, the normally open stop lamp switch closes and the normally closed TCC brake switch opens. The cruise control module detects a high signal voltage on the stop lamp switch signal circuit and a low signal voltage on the TCC brake switch/cruise control release signal circuit. Depressing the clutch pedal while the cruise control is engaged will disengaged the cruise control system. When the clutch pedal is depressed, the normally closed CPP switch opens and the cruise control module detects a low signal voltage on the CPP switch signal circuit. The vehicle speed stored in the memory of the cruise control module will be erased when the cruise control On/Off switch is turned Off, or the ignition switch is turned off.

When the cruise control system is disengaged, the PCM sends a class 2 message to the IPC in order to deactivate the cruise control indicator.

Cruise Control Inhibited

The cruise control module assembly contains a low speed limit which will prevent system engagement below a minimum speed of 40 km/h (25 mph).

The cruise control will not engage if the cruise control module detects a low voltage signal on the CHMSL supply voltage/stop lamp supply voltage circuit when the brake pedal is depressed.

Cruise Control Description and Operation 4.8L, 5.3L, 6.0L, and 8.1L

Cruise control is a speed control system that maintains a desired vehicle speed under normal driving conditions at vehicle 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:

Cruise Control Engaged

The throttle actuator control (TAC) module monitors the signal circuits of the following cruise control switches:

The powertrain control module (PCM) will engage and adjust vehicle speed based on the information received from the TAC module via the UART serial data link. For further information on the TAC System, refer to Throttle Actuator Control (TAC) System Description for the 4.8L, 5.3L, and 6.0L engine or to Throttle Actuator Control (TAC) System Description for the 8.1L engine.

The cruise control switches are located on the multifunction/turn signal lever.

Ignition positive voltage is supplied from the 10-ampere CRUISE fuse to the cruise control switch via the ignition 3 voltage circuit. When the normally open cruise control On/Off switch is turned On, the switch closes and the TAC module detects a high signal voltage on the cruise control on switch signal circuit. When the normally open Set/Coast switch is pressed, the switch closes and the TAC module detects a high signal voltage on the cruise control set/coast switch signal circuit. To engage the Cruise Control System, turn the On/Off switch On and momentarily press the Set/Coast switch. The TAC module sends a UART message to the PCM, in order to confirm that the cruise control enable criteria has been met. The PCM will engage the Cruise Control System and record the selected vehicle speed. The PCM sends a class 2 message to the instrument panel cluster in order to illuminate the cruise control indicator. 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 is momentarily pressed, with a minimum vehicle speed of 37 km/h (23 mph). When the normally open Resume/Accel switch is activated, the switch closes and the TAC module detects a high signal voltage on the cruise control resume/accel switch signal circuit. 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.

Cruise Control Disengaged

The powertrain control module (PCM) disengages the cruise control operation based on the information received from the throttle actuator control (TAC) module. The TAC module monitors the signal circuits of the following switches:

The TCC brake switch and the stop lamp switch are incorporated into an assembly and are mounted to the brake pedal bracket. Pressing the brake pedal while the cruise control is engaged will disengaged the Cruise Control System. The TAC module monitors the stop lamp switch signal circuit and the PCM monitors the TCC brake switch/cruise control release signal circuit. When the brake pedal is pressed, the normally closed TCC brake switch opens and the normally open stoplamp switch closes. The TAC module detects a high signal voltage on the stop lamp switch signal circuit and the PCM detects a low signal voltage on the TCC brake switch/cruise control release signal circuit. The TAC module sends a UART message to the PCM indicating the status of the stop lamp switch. The CPP switch is mounted to the clutch pedal bracket. Depressing the clutch pedal while the cruise control is engaged will disengaged the Cruise Control System. When the clutch pedal is depressed, the normally closed clutch switch opens and the PCM detects a low signal voltage on the clutch pedal position switch signal circuit. The Cruise Control System will disengage when the cruise control On/Off switch is turned Off. The vehicle speed stored in the memory of the PCM will be erased when the cruise control On/Off switch is turned to Off, or the ignition switch is turned OFF.

The Cruise Control System will disengage when the PCM detects that the driver has the accelerator pedal override 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.

Cruise Control Inhibited

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

Cruise Control Description and Operation 6.6L

Cruise control is a speed control system that maintains a desired vehicle speed under normal driving conditions at vehicle 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:

Cruise Control Engaged

The cruise control system will engage and adjust vehicle speed based on the activation of the following cruise control switches:

The engine control module (ECM) monitors the signal circuits of the cruise control switches in order to determine when to capture and maintain the selected vehicle speed. The ECM monitors the vehicle speed sensor signal circuit in order to determine the vehicle speed. The ECM uses the throttle actuator control (TAC) motor in order control the vehicle speed. Ignition positive voltage is supplied from the 10-amp IGN E fuse, to the cruise control switch via the ignition 1 voltage circuit. When the normally open cruise control On/Off switch is turned ON, the switch closes and the engine control module detects a high signal voltage on the cruise On/Off switch signal circuit. When the normally open Set/Coast switched is pressed, the switch closes and the engine control module detects a high signal voltage on the Set/Coast signal circuit. To engage the cruise control system, the On/Off switch must be ON and the set button momentarily pressed. The ECM will confirm that the cruise control enable criteria has been met. When the ECM determines that the cruise control enable criteria has been met, the ECM will engage the cruise control system and record the selected vehicle speed. The ECM will then send a class 2 message to the instrument panel cluster (IPC) in order to activate the cruise control indicator. 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 engine control module 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 is momentarily pressed, with a minimum vehicle speed of 37 km/h (23 mph). When the normally open Resume/Accel switch is activated, the switch closes and the engine control module detects a high signal voltage on the cruise control Resume/Accel switch signal circuit. 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 engine control module 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 engine control module.

Cruise Control Disengaged

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

The TCC/brake switch and the stop lamp switch are used to disengage the cruise control. The stop lamp and TCC/brake switch are incorporated into an assembly and are mounted to the brake pedal bracket. When the brake pedal is pressed, the normally closed TCC/brake switch opens and the normally open stop lamp switch closes. The engine control module detects a low signal voltage on the TCC/brake signal circuit and detects a high signal voltage on the stop lamp signal circuit. The vehicle speed stored in the memory of the engine control module will be erased when the cruise control On/Off switch is turned OFF, or the ignition switch is turned OFF.

The cruise control system will disengage when the ECM detects that the driver has the accelerator pedal override active for approximately 60 seconds.

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

Cruise Control Inhibited

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