Pedestrian protection function - GF91.60-P-1005FL

MODEL 212 with CODE U60 (Pedestrian protection) 

Function requirements, general 

• Vehicle speed v = 25 to 55 km/h
• Terminal 15 ON

The instrument cluster (A1) sends information concerning the vehicle speed up to 28.2.13 via chassis CAN (CAN E) or as of 1.3.13 via chassis CAN 2 (CAN E2), the front SAM control unit with fuse and relay module (N10/1) and chassis CAN 1 (CAN E1) to the supplemental restraint system control unit (N2/10).

The status of circuit 15 is sent by the electronic ignition lock control unit (N73) via chassis CAN (up to 28.2.13) or chassis CAN 1 (as of 1.3.13) to the supplemental restraint system control unit.

Pedestrian protection, general 

The pedestrian protection function reduces the level of injury severity in the event of any collision with a pedestrian. The space between the engine hood and the components below is increased by the engine hood moving up suddenly in the area of the A-pillar. This space prevents the pedestrian from being hit directly by the components below the engine hood.

Pedestrian protection includes the following subfunctions:

• Function sequence for impact recognition 
• Function sequence for triggering pedestrian protection (up to 28.2.13) 
• Function sequence for triggering pedestrian protection (as of 1.3.13) 
• Function sequence for resetting engine hood after triggering (up to 28.2.13) 

Function sequence for impact recognition 

The supplemental restraint system control unit reads in the signals from the following sensors directly:

• Left front bumper pedestrian protection sensor (B151/1)
• Center front bumper pedestrian protection sensor (B151/2) (up to 28.2.13)
• Right front bumper pedestrian protection sensor (B151/3)

Up to 28.2.13:

In accordance with the acceleration values determined by the bumper pedestrian protection sensors, a decision is made about triggering the pedestrian protection.

As of 1.3.13:

In accordance with the pressure values determined in a hose by the bumper pedestrian protection sensors, a decision is made about triggering the pedestrian protection.

The pedestrian protection may be actuated by mistake in a collision with other objects (e.g. pole, guide post or thicker branches).

Function sequence for triggering pedestrian protection (up to 28.2.13) 

The supplemental restraint system control unit activates the following actuators to raise the engine hood:

• Left rear engine hood lifter (Y127/1)
• Right rear engine hood lifter (Y127/2)

Function sequence for triggering pedestrian protection (as of 1.3.13) 

The supplemental restraint system control unit activates the following actuators to raise the engine hood:

• Left active engine hood squib (R12/49)
• Right active engine hood squib (R12/50)

The pyrotechnical engine hood lifters are not designed to be reversible.

Function sequence for resetting engine hood after triggering (up to 28.2.13) 

The engine hood lifter is designed reversibly. After triggering, the engine hood can be returned manually to its initial position. For this purpose unlock engine hood and open completely. After closing the engine hood, resetting is completed.

Complete closing of the engine hood is detected by the following sensors:

• Pedestrian protection + ATA [EDW] engine hood switch Hall sensor (A38/1)
• Pedestrian protection Hall sensor (B100)

The supplemental restraint system control unit reads in the signals of the pedestrian protection Hall sensors directly. If the engine hood was not completely closed, a corresponding message will appear in the multifunction display (A1p13) of the instrument cluster. The request for output of this message is sent by the supplemental restraint system control unit via chassis CAN to the instrument cluster.

The pedestrian protection Hall sensors only recognize whether the engine hood is completely closed. They do not recognize, whether the engine hood has been reset correctly. After resetting the engine hood, the pedestrian protection function can be immediately activated again