The speed control system is integrated within the engine management system and uses fuelling intervention to automatically maintain a set vehicle speed. Once engaged, the speed control system can also be used to accelerate the vehicle without using the accelerator pedal. The speed control system comprises the following components:
The speed control is operated by the driver using the steering wheel switches. When the speed control is active (by pressing ACC switch on and after pressing set + or -), the PCM regulates the vehicle speed so that it is equal to or less than that of the set speed depending upon the traffic situations.
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Proximity warning radar unit
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Proximity warning module
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Adaptive speed control steering wheel switches
In addition to the standard speed control system, the adaptive speed control system uses the proximity warning radar unit to detect the speed, distance and range rate of vehicles ahead of it.
The adaptive speed control system is similar to conventional speed control in that it maintains the vehicle's pre-set speed. However, unlike conventional speed control, the adaptive speed control system can automatically adjust speed in order to maintain a suitable distance between vehicles in the same lane. This is achieved through the proximity warning radar unit, proximity warning module and is controlled by the adaptive speed control steering wheel switches. If the vehicle in front slows down, or if another object is detected, the adaptive speed control system sends a signal to the engine and braking system to decelerate. Then when the road is clear, the adaptive speed control system will accelerate the vehicle back to the set speed.
The adaptive speed control system is also capable of assisting the driver when the brakes need to be applied in an emergency situation.
When the forward alert system detects that a collision with an object in front of the vehicle may occur, an audible and visual warning is displayed in the instrument cluster. The warning level can be adjusted to suit the driver. In addition to the driver warning, the forward alert system calculates the need of assisting the driver in a braking situation by a possible precharge of the brake pressure by raising the emergency brake assist (EBA) level.
In general, the system is only reacting on movable (non-stationary) targets and has a requirement of minimum speed to be activated.
Adaptive speed control and forward alert are not available on vehicles with a standard anti-lock braking system (ABS) or standard stability assist module. Adaptive speed control works only in combination with an enhanced stability assist module or an anti-lock brake system/traction control module which is standard on vehicles that are equipped with continuous damping control (CDC).
Speed Control Steering Wheel Switches
Information about the adaptive speed control system is displayed to the driver in the instrument cluster. Details of the speed and the distance in time are shown. When the adaptive speed control system detects that a collision is imminent, the instrument cluster will also display an audible and visual warning alerting the driver.
Service Alignment Procedure
This procedure is required if:
- A new proximity warning radar unit and, or proximity warning module are installed
- The proximity warning radar unit needed to be removed or is misaligned in its position due to another repair operation.
Install new components to the vehicle. Make sure that the vehicle is on level ground.
If the radar assembly was the only new component to be installed, the adaptive speed control system will automatically enter 'Service Alignment Mode'.
The follow indicator will now be flashing, this indicates that the vehicle is in "service alignment" and now requires driving.
The service alignment process measures the path of stationary targets such as streetlights, railings, road signs, parked vehicles etc., and uses this data to correct for radar misalignment. Alignment will complete more quickly if more suitable targets are seen. The following recommendations will help:
- The vehicle speed must be above 30 mph (48 kph).
- Choose a road with plenty of road furniture. Use an inside or outside lane.
- Following vehicles too closely will obscure the stationary targets from the radar, a time gap of 2 seconds is recommended.
- A straight road will produce a quicker and better result, although the process will still operate on a curved road.
- The time the adaptive speed control module takes to align will vary, depending on the route, speed, number of targets, and individual module.
- When the flashing follow indicator light extinguishes, the adaptive speed control system is now functional, and a required vehicle speed can now be set by the driver and the adaptive speed control system will operate as normal.
