EBD
The two brake circuits are split diagonally. One circuit supplies the left-front and right-rear brakes with appropriate hydraulic pressure, the other supplies the right-front and left-rear.
Matched software in the ABS Control Module (w/EDL) -J104-, Electronic Brake Distribution (EBD) carries out the function of the mechanical/hydraulic brake pressure regulator.
The signal sent to the instrument cluster when the ABS fails is pulsed, if the EBD function continues in emergency mode. The instrument cluster distinguishes between no signal, a pulsed signal, and a steady signal. The ABS/EDS indicator light and the red symbol for "Brake system malfunction" light accordingly.
Scheme 224
- Terminal 15
- Signal for controlling the ABS/EDL indicator light and the red brake warning symbol
- Voltage supply for the ABS/EDL indicator light
- Voltage supply for the red brake warning symbol
Scheme 225
- In interval "A" (with "ignition on(" a self-test of the ABS/EDL indicator light is carried out for two seconds using signal "2" (light lights up). During this interval, the instrument cluster suppresses the red brake warning symbol.
- Signal "2" is not available in interval "B." The ABS/EDL indicator light and the red brake warning symbol do not light.
- In interval "C", the On Board Diagnostic recognized a DTC, which did not deactivate the EBD. Signal "2" is pulsed. Only the ABS/EDL indicator light comes on.
- In interval "D", the On Board Diagnostic recognized a DTC, which did deactivate the EBD. Signal "2" is steady. The ABS/EDL indicator light and the red brake warning symbol light.
The red brake warning symbol indicates the EBD is deactivated. The vehicle is only allowed to be driven under restricted conditions. Test Drive the vehicle, see TEST DRIVE .
For additional information about EBD indicator light control, see: "Indicator light functions, overview". See INDICATOR LIGHT FUNCTIONS, OVERVIEW .
ABS prevents the wheel from locking up during hard braking initiated by the driver. ABS regulates the brake system pressure in the individual brake cylinders with respect to the individual wheel speed, brake deceleration and slip, to ensure optimal braking of the wheels on the road surface.
The Electronic Differential Lock (EDL) is a traction control aid for driving away from a standstill. An electronically-controlled brake application at the wheel that is spinning provides a torque reaction point for the differential. This enables the wheel with better traction to make use of the engine power. EDL is effective in both forward and reverse.
On vehicles with all-wheel-drive, EDL controls all four wheels. This makes it possible to eliminate the driver operated mechanical differential lock.
EDL as part of ESP and is effective at any speed.
The function of ASR requires an exchange of signals between the ABS Control Module (w/EDL) -J104-, the Engine Control Module (ECM) and the Transmission Control Module (TCM) (only for vehicles with automatic transmission). The control modules communicate with each other.
The data is transferred via CAN-bus. See CAN-BUS, FUNCTION .
The ASR traction control system prevents the driven wheels from spinning under acceleration; the system operates by reducing engine torque and is active at all speeds. The EDL and ASR functions are combined in order to assist acceleration.