Adaptive Speed Control Module
Component Location
| ITEM | DESCRIPTION |
|---|---|
| 1 | Adaptive Speed Control Module (ASCM) |
| 2 | Electrical Connection |
The Adaptive Speed Control Module (ASCM) is mounted on a bracket which is attached to the front bumper beam.
The ASCM contains a forward looking radar transceiver together with related controlling hardware and software. A High Speed (HS) Controller Area Network (CAN) chassis bus connection allows the ASCM to communicate with other system control modules. Power supplies to the ASCM are from the extended ignition relay in the Rear Junction Box (RJB).
The ASCM is active whenever the ignition is on (Power Mode 6), even if speed control is not engaged. The forward alert, Advanced Emergency Brake Assist (AEBA) and Intelligent Emergency Braking (IEB) functions also use the ASCM. With the ignition on (Power Mode 6), the ASCM is electrically powered, but no radar transmissions are emitted until the vehicle starts moving.
The ASCM transmits a radar beam forward of the vehicle and detects the returning signals reflected off other vehicles and objects ahead. The radar beam is electronically scanned in seven zones across a total arc of 30° centered on the longitudinal axis of the vehicle. The vertical coverage of ±5° from nominal position. The radar operates at millimetric wavelengths (76 - 77 GHz) and transmits a frequency modulated continuous wave signal at a relatively low power level (no high power pulses). The control module detects the range, relative velocity and angle of objects within the scanned arc for up to a distance of approximately 150 meters (500 feet).
The ASCM compares vehicle speed data from the Anti-lock Brake System (ABS) control module with the relative speed of an external object. The speed of the objects is detected by the radar to determine that the object is stationary or not. If tires are equipped which are different in diameter from those specified for the vehicle, the speed of the vehicle will not be the true road speed. The speed of the vehicle is calculated by the ABS control module. This situation may cause stationary objects to be falsely identified as moving vehicles and result in automatic deceleration on a clear road.
The ASCM continuously monitors both moving vehicles and stationary objects to determine if it can 'see' normally. If the ASCM can detect only a few objects, or there are few roadside objects or other vehicles in the area, it may determine that it is blocked. For example by an accumulation of snow or mud on the lower grill of the front bumper, or an incorrectly located licence plate. The ASCM then inhibits adaptive speed control and records a Diagnostic Trouble Code (DTC). The system will reset after an ignition cycle. In this case the ASCM does not have a fault and should not be replaced.
The ASCM requires mechanical vertical alignment using the approved service tool if it is replaced in service. Horizontal alignment is achieved by putting the ASCM into service mode using the Jaguar Land Rover (JLR) approved diagnostic equipment. The vehicle then needs to be driven for a short period while the ASCM does a calibration routine. Calibration is complete when the follow mode warning indicator in the Instrument Cluster (IC) stops flashing.
For additional information, Refer to: ADAPTIVE SPEED CONTROL MODULE ADJUSTMENT