1. Brake Switch
This switch is mounted on the pedal assembly and is used to send the status of the brake pedal to the HECU.
The switch is turned on when the brake pedal is pressed. The brake light switch is a normally-open contact type which runs to battery voltage when it is active (this means that the brake pedal is pressed). When it is passive (this means that the brake pedal is released), the line is grounded via the brake light bulb.
The brake light signal is a reference to judge driver's intention for braking.
The HECU checks open or short circuit of brake light switch for normal ESP control.
If an error is present, the warning lamp will illuminate.
Item
Detecting Condition
Possible cause
DTC Strategy
Open circuit monitoring
Open circuit in brake switch line
Faulty brake light switch
Faulty input stage in HECU
MonitoringPeriod
Continuous (only normal voltage)
Enable Conditions
In case of over 10kph speed and under 5 bar of Pressure sensor input, monitoring a fault if BLS keeps on for 60s
Monitoring a fault if BLS keeps off for 2s 3s in case of over 15 bar of pressure sensor input
Monitoring a fault if BLS keeps off for 1s in case of over 50 bar of pressure sensor input
Fail Safe
Inhibit the ESP control and allow the ABS/EBD control
The ESP warning lamp is activated
Brake Light Switch
Voltage Range of "High"
Voltage Range of "Low"
7.0V ~ 16.0V
0V ~ 3V