The EPB system is the shorten word of Electric Parking Brake system. This system is the parking brake device which is used instead of the conventional hand-break system. When a driver presses the EPB button, the button signal is delivered to the EPB ECU and then the EPB actuator which consists of a motor and a gears is activated. At this time, while the motor in the EPB actuator rotates, the motor pulls the EPB cable connected to the rear wheels. The EPB ECU senses a driver's intention by the EPB switch. When trying to operate the parking-brake, this can be done just by pushing the EPB switch. And when the EPB switch is pulled, the parking-brake is released.
The EPB ECU monitors the signal of the EPB switch and if it is detected as an error in the circuit, this DTC is set.
Item
Detecting Condition
Possible Cause
DTC Strategy
Switch signal monitoring
Open/Short in the EPB switch circuit
Faulty EPB switch
Unusual operation for EPB switch
Threshold value
When there is an error in the EPB switch circuit
When the EPB switch is abnormally operated
(The EPB Switch is excessively operated or The EPB switch's operating signals are inputted over 90 seconds or The EPB switch is being slowly operated)
Fail-Safe
The EPB switch's signals are ignored.
EPB Switch
EPB Switch pushed
EPB Switch pulled
Resistance
between SW1 and SW4
3.91 K? ± 3%
1.3 K? ± 3%
between SW2 and SW5
0.9 K? ± 3%
3.98 K? ± 3%