Topics:
Cruise control:
Cruise control is an automatic speed controller, also known as a “cruise controller”. The system makes long-distance driving more comfortable because the driver does not have to keep pressing the accelerator pedal continuously.
The cruise control is an electronic system that regulates the fuel supply to the engine so that the set speed is automatically maintained. The driver sets the desired speed with a switch or control lever, after which the accelerator pedal can be released. The car then continues to drive at the same speed, even on slight inclines.
When the brake or clutch pedal is operated, the system automatically switches off to return control to the driver. In many modern vehicles, the last set speed is stored so it can easily be reactivated. There are various types of cruise control:
- Conventional cruise control: only keeps the speed constant. The driver sets this with a button or lever and can also adjust the speed manually.
- Adaptive cruise control (ACC): automatically adjusts the speed based on the distance to the vehicle in front by means of radar or camera sensors. If a large deceleration is required, the brakes are also operated via the ACC.
- Intelligent cruise control: combines the adaptive function with traffic sign recognition, allowing the speed to be automatically adjusted to the applicable speed limit.
The use of cruise control can help reduce fuel consumption, because the speed remains constant and there are fewer unnecessary accelerations. In addition, it helps the driver to avoid speeding violations and increases driving comfort, especially on long journeys on motorways.
The system is particularly suitable for use on relatively flat roads. This is important because in vehicles with a low-powered engine (few hp) and a manual gearbox, problems can occur on inclines, especially when heavily loaded. If the driver does not shift to a lower gear in time, the engine speed can drop too far. As a result, the engine has to work too hard at low revs, which can lead to overheating and higher fuel consumption.
An automatic transmission will shift down by itself if the load is too high at too low an engine speed.
When driving downhill, the cruise control can temporarily shut off the fuel system or inject less fuel to slow the vehicle down. As soon as the set speed can no longer be maintained because gravity is accelerating the car, the driver must intervene. If the system is at its minimum setting and the speed continues to increase, the engine speed can become too high. This increases the risk of engine damage.
Therefore, it is important that when driving uphill or downhill the driver switches off the cruise control in time and manually monitors the engine speed by selecting the appropriate gear.
Faults:
The engine management system continuously monitors the signals from the clutch and brake pedal sensors, as well as the signals from the cruise control switch. When the system detects a deviant or illogical sensor value, the cruise control is automatically disabled or cannot be activated. This prevents the car from unintentionally accelerating or decelerating and thereby causing dangerous situations.
When reading out the engine management system with diagnostic equipment, a fault code is stored. This code, in combination with the live data, indicates whether the switch signal is being transmitted correctly in the rest position and during operation.