6
TEBS E
GIO functions
118
6.26 Emergency stop light (Emergency Brake Alert)
Vehicle type
All trailer vehicles
Purpose
If the vehicle is in a hazardous situation and needs to brake abruptly, emergency
braking can be indicated by making the trailer stop lights flash.
Function
In TEBS E a separate GIO output is provided for this to which the stop light is con-
nected via a relay. The relay does so by interrupting the stop light using a specific
preset frequency.
In some towing vehicles, the function for the trailer stop lighting is monitored so
that a basic load exists in relay operation in both switch states (stop light or resis-
tance), so that no error is detected from the towing vehicle.
For compatibility with the towing vehicle's stop light error recognition process,
WABCO recommends building in a resistance of 100 Ohm parallel to the relay.
The GIO output is allowed to be loaded to maximum 1.5A.
Activation
The function is automatically activated by the TEBS E modulator depending on the
following situations:
• If the vehicle deceleration is greater than 0.4 g in an emergency braking proce-
dure.
• If an ABS control procedure occurs at a speed of > 50 km/h.
The function is ended again if the vehicle deceleration is under the value 0.25 g or
the ABS control is deactivated again.
The speed threshold for the emergency brake light can be reduced by
means of a parameter and can thus also be used for agricultural vehi-
cles.
Components
Extract from diagram 841 802 291 3
The following components can be used for indication:
Item Component Part number
1 Stop light (LED or bulb)
max. 24 V, 1.5 A
Not part of WABCO's scope of supply