Cruise Control: Description and Operation
CRUISE CONTROL DESCRIPTION AND OPERATION
SYSTEM DESCRIPTION
The cruise control system on the FWD vehicle is integrated into the powertrain control module (PCM).
RES/ACC SWITCH
The RES/ACC (Resume/Accelerate) switch returns cruise control system operation to the last speed setting after a cancel input signal is received by the cruise control module, such as vehicle braking. This switch is activated when the cruise control switch is momentarily moved upward. Do not hold the cruise control switch in this position. Release it immediately. If the cruise control switch is held in the RES/ACC position for more than one second, the system goes into the accelerate mode. If acceleration during cruise control system operation is desired, move the cruise control switch upward into the RES/ACC position and hold it there until the vehicle reaches the desired speed. When the cruise control switch is released, the cruise control system will maintain the new cruise speed. In order to use the accelerate mode, the cruise on/off switch button must have been pressed, the CRUISE indicator must be lit, and the vehicle speed must be over 40 km/h (25 mph).
SET/COAST SWITCH
The SET/COAST switch is activated when the cruise control switch is moved downward into the SET/COAST position. When the cruise control switch is moved downward into the SET/COAST position and released, the cruise speed will be set at the speed at which the vehicle was traveling when the switch was activated. In order for this switch to operate, however, the cruise on/off switch button must have been pressed, the CRUISE indicator must be lit, and the vehicle speed must be over 40 km/h (25 mph).
The SET/COAST switch can also be used to decrease the cruise speed. By moving the cruise control switch downward into the SET/COAST position and holding it there, the cruise control system will disengage and allow the throttle to return to the idle position. When the new, lower cruise speed has been reached, the cruise control switch is released from the SET/COAST position. Once released, the cruise control system will re-engage and maintain the new desired cruise speed.
The SET/COAST switch can also be used to tap-down vehicle speed. In order to do this, the cruise control system must be engaged and operating. Tapping-down is performed by quickly moving the cruise control switch down into the SET/COAST position and releasing it (or tapping the switch into the SET/COAST position). Do not hold the cruise control switch in the SET/Coast position, or the cruise control system will enter the coast mode. Tap-down is a function in which cruise speed can be decreased by 1.6 km/h (1 mph) increments (one tap = 1.6 km/h (1 mph) decrease).
The accelerator may be pressed at any time to override cruise control system operation. Release of the accelerator will return the vehicle to the previously set cruise speed.
VEHICLE SPEED SENSOR DESCRIPTION
The vehicle speed sensor (VSS) is an electronic relay that is mounted on the transaxle. As the transaxle turns the VSS, the VSS provides the speedometer with a vehicle speed input (voltage pulses). This input is used to drive the speedometer. The speedometer then converts the vehicle speed input into a more precise waveform and provides the powertrain control module (PCM) and the cruise control module with its own vehicle speed input. The cruise control module converts this input into a vehicle speed. For VSS replacement procedures, refer to Vehicle Speed Sensor (VSS) Replacement in Automatic Transmission - MU4, Vehicle Speed Sensor (VSS) Replacement in Manual Transmission - MK5, or Vehicle Speed Sensor (VSS) Replacement in Manual Transmission - MTN.
The RES/ACC switch can also be used to tap-up vehicle speed. In order to do this, the cruise control system must be engaged and operating. Tapping-up is performed by quickly moving the cruise control switch up into the RES/ACC position and releasing it, or tapping the switch into the RES/ACC position. Do not hold the cruise control switch in the RES/ACC position, or the cruise control system will enter the accelerate mode. Tap-up is a function in which cruise speed can be increased by 1.6 km/h (1 mph) increments (one tap = 1.6 km/h (1 mph) increase).
STOP LAMP SWITCH DESCRIPTION
The stop lamp switch is located under the instrument panel (I/P) directly above the brake pedal. Whenever the brake pedal is pressed, one set of stop lamp switch contacts close and a voltage signal is provided to the cruise control module. The cruise control module disengages cruise control system operation as soon as this voltage signal is sensed.
When the brake pedal is pressed, another set of stop lamp switch contacts open, and the voltage circuit from the cruise control module to the magnetic clutch inside the servo is interrupted. With voltage removed from the magnetic clutch, the servos DC servo motor is disengaged from the worm gear and the throttle is permitted to return to the idle position. This feature is provided to ensure the cancellation of cruise control system operation during vehicle braking. For stop lamp switch replacement and adjustment procedures, refer to Stop Lamp Switch Replacement in Lighting Systems.
CLUTCH CONTROL RELEASE SWITCH DESCRIPTION
The cruise control release switch is mounted under the instrument panel (I/P) directly above the clutch pedal. Whenever the clutch pedal is pressed, the cruise control release switch closes and provides a ground to the cruise control module. The cruise control module disengages cruise control system operation as soon as this ground signal is sensed.
PARK/NEUTRAL POSITION (PNP) SWITCH DESCRIPTION
The park/neutral position (PNP) switch (2) is mounted to the transaxle. Whenever the manual selector lever is placed in either the Park (P) or Neutral (N) position, the PNP switch closes and provides a ground to the cruise control module. The cruise control module disengages cruise control system operation as soon as this ground signal is sensed. For PNP switch replacement and adjustment procedures, refer to Park/Neutral Position Switch in Automatic Transaxle - MU4.
CRUISE ON OFF SWITCH
The CRUISE ON OFF switch is a momentary contact type button located on the end of the cruise control switch. The purpose of the CRUISE ON OFF switch is to turn the cruise control system ON and OFF.
CRUISE INDICATOR DESCRIPTION
The CRUISE indicator, located in the instrument cluster assembly, turns ON to inform the driver that the cruise control system is operational. The CRUISE indicator is also used during cruise control system diagnosis.
SYSTEM OPERATION
To Set Cruise Control
1. Drive the vehicle above 40 km/h (25 mph)
CAUTION: Do not use the cruise control on slippery roads, steeply graded roads, or in heavy traffic of heavy or varying volume. Failure to follow these CAUTIONS could possibly cause you to loose control of the vehicle and result in damage to the vehicle and personal injury.
2. Depress and release the CRUISE ON OFF button.
3. Accelerate to the desired speed.
4. Move the cruise control switch downward to the SET/COAST position and release.
5. Take your foot off the accelerator pedal.
To Resume A Set Speed
Suppose you set your cruise control at a desired speed and then you apply the brake. This, of course, shuts off the cruise control. But you do not need to reset it. Once you are going 40 km/h (25 mph) or more, you can move the cruise control switch upward to the RES/ACC position and release. You will go right back up to your chosen speed and stay there. Turning the ignition OFF or turning the cruise switch OFF, you will erase set speed memory. Earlier models will also erase set speed memory if the vehicle speed drops below 40 km/h (25 mph).
To Get Out Of Cruise Control
There are 3 ways to turn OFF the cruise control.
- Step lightly on the brake pedal.
- Press and release the CRUISE ON OFF button.
- Press the clutch pedal - manual transmissions.
Passing Another Vehicle While Using Cruise Control
Use the accelerator pedal to increase your speed. When you take your foot off the pedal, the vehicle will slow down to the cruise control speed you set earlier.
To Increase Speed While Using Cruise Control
There are 2 ways to gain higher speed while using cruise control.
- Use the accelerator pedal to get to the higher speed, move the cruise control switch downward to the SET/COAST position and release. You will now cruise at the higher speed.
- Move the cruise switch upward to the RES/ACC position, hold it there until you get up to the speed you want and release. To increase your speed in very small amounts, move the cruise control switch upward to the RES/ACC position for less than 3/4 of a second and release it. Each time you do this, your vehicle will go approximately 1.6 km/h (1 mph) faster.
The accelerate feature will only work after you turn ON the cruise control by pushing and releasing the CRUISE ON OFF button and setting a cruise control speed.
Using Cruise Control On Hills
How well your cruise control will work on hills depends upon your speed, load, and the incline of the hills. When going up steep hills, you may have to step on the accelerator pedal to maintain your speed. When going downhill, you may have to brake or shift to a lower gear to keep your speed down. Of course, applying the brake takes you out of cruise control. Many drivers find this to be too much trouble and do not use cruise control on steep hills.
To Erase Cruise Speed Memory
When you turn OFF the cruise control switch or the ignition is turned OFF the cruise control set speed memory is erased. On earlier models, set speed memory will also be erased if the vehicle speed drops below 40 km/h (25 mph).
To Reduce Speed While Using Cruise Control
There are 2 ways to reduce your speed while using cruise control.
- Move the cruise control switch downward to the SET/COAST position and hold until you obtain the lower speed you want. Then release it.
- To slow down in very small amounts move the cruise control switch downward to the SET/COAST for less than 3/4 of a second and release. Each time you do this, you will go approximately 1.6 km/h (1 mph) slower.