BAS PLUS, function - GF30.30-P-3310SX

ENGINE 156, 273, 275 in MODEL 216 with CODE (233) Distronic Plus up to Model Year 8

ENGINE 156, 272, 273, 275, 642, 629 in MODEL 221 with CODE (233) Distronic Plus up to Model Year 8

Fig 1: View Of Accident-Critical Situation Detection

Courtesy of MERCEDES-BENZ USA

Detection of potential accident situations by BAS PLUS

The BAS PLUS function is an additional function of the Brake Assist System (BAS), which assists the driver during emergency braking by means of specific calculations of the brake force for a given situation.

The data from the long and short range radar is used to continuously calculate the potential risk of a collision. If the driver brakes heavy in a critical situation, the brake force is (if necessary) boosted so as to avoid a collision (within physical limits).

Function requirements

"ADTR_AVL" (DISTRONIC PLUS) coded in central gateway control unit (N93)
Radar sensor system not disabled
Dirt/function test of the long range radar completed
"Circuit 61 ON" (engine running)
Parking brake not applied
DIRECT SELECT gear selector switch (S16/13) in "D" position

Activation

BAS PLUS is activated when:

A potential accident situation is detected
Heavy driver-induced braking is detected from the brake pedal travel and the actuation speed of the brake pedal
Accelerator not operated
The vehicle is moving forwards

Potential accident situation

The distance between the vehicle and a detected object is recognized to be critical for an imminent collision at the current closing speed. The objects in question are all objects in front of the vehicle that have been detected at least once as moving at speeds (of the host vehicle) up to 70 km/h as well as stationary objects.

The sensor data from the long range and short range radar and the input signals are evaluated by the radar sensors control unit (SGR) (N62/1) and the necessary braking torque to support the Brake Assist System is calculated.

The computed braking torque is transmitted via the chassis CAN to the ESP control unit (N47-5), which controls the brake pressure accordingly via the traction system hydraulic unit (A7/3). The necessary braking torque is continuously recalculated by the radar sensors control unit on the basis of the current distance and the closing speed, and is relayed to the ESP control unit. Depending on the situation, anything up to full emergency braking may occur.

Deactivation

If the driver reduces the brake pedal travel significantly to within an absolute or percentage cancellation threshold, the assistance is decreased until only the driver-induced braking (depending on brake pedal travel) remains and BAS PLUS is deactivated. Likewise, the function of BAS PLUS is deactivated if the accelerator pedal is depressed.

Component description for the DTR controller unit	A89	GF30.30-P-3210SX
Component description for the radar sensors control unit	N62/1	GF30.30-P-3301SX
Component description for the bumper radar sensors	A86/1b1-4, A86/2b1-4	GF30.30-P-3302SX