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Vehicle Dynamics and Driver Assist Systems
May 2017
Sliding Prevention
The Sliding Prevention feature of the EPB allows for self-activation of the EPB motor to
increase the tension to the brake pads, if the parking brake had been previously set. Sliding
Prevention is activated if the wheel speed sensors detect vehicle movement within 15 minutes
of the EPB activation.
Temperature Compensation
The Temperature Compensation feature of the EPB functions by calculating brake component
temperature from information obtained by the CAN and HCU. The Ambient air temperature,
vehicle speed, road incline, service brake use frequency, and other vehicle information are
considered when calculating brake component temperature. Higher temperatures equate to
expanded parts which will contract as they cool. This could produce a situation where the
initial EPB activation is not strong enough to maintain vehicle position. Compensation for high
temperature is achieved by two methods;
1. The EPB is activated with the Engine operating or CAN still operating. All necessary
data is available to the EPB control unit (HCU) and the EPB motor applies additional
mechanical force to the brake pads.
2. The EPB is activated with the Engine off and the CAN in sleep mode. Data to determine
brake component temperature is not available to the EPB control unit (HCU). The initial
EPB activation will be limited to learned values. An additional application of the EPB
motor will be self-activated by the EPB control unit (HCU) 2 minutes and 30 seconds
after the EPB was initially set. This will tighten any clearances that may have developed
from contracting brake parts.
Note: An Automatic adjustment procedure is performed if no EPB operation is
detected. The EPB control unit (HCU) monitors the driving mileage and will self-
activate the EPB with the engine off once every 1864 miles (3000 kilometers).
This procedure repositions the ball nut clearance from the back face of the
hydraulic piston and tests the EPB motor drive circuits. The EPB will remain on
after the adjustment. EPB release is accomplished with the automatic release
feature or manual release while pressing the brake pedal.
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