4
Passive Entry / Passive Start
From outside the vehicle: Touch car door (PE)
From inside the vehicle: Press "start" button on dashboard (PS)
LF from car awakens fob (LF downlink)
Fob measures field strength vectors & sends info to vehicle
Fob orientation is arbitrary - must measure x, y, & z axis (3D)
Fob localized: Allow "Unlock" if outside (confirm if 2-way RF)
Fob localized: Allow "Start" if inside (confirm if 2-way RF)
Important system design considerations:
LF field strength regulation over across voltage/temp/coil variation
Accurate LF field strength measurement
High LF field sensitivity
Car Access – Basic of PEPS
outside
detection
outside
detection
outside rear
detection
inside
detection
trunk
separation
outside
detection
outside
detection
