Component description Electrohydraulic shut-off device EHAB The EHAB (electrohydraulic shut-off device) is a safety-relevant component. The EHAB shuts off the fuel supply to the injection pump in the event of certain faults oc- curring in the EDC system. The EHAB is connected in the fuel supply system between the delivery pump and pump suction chamber. The EHAB reverses the delivery direction of the delivery pump so that the pressure in the suction chamber is reduced rapidly thus interrupting the filling procedure. Power is always applied to the EHAB during operation. The power circuit is interrupted by the EDC control unit in order to activate the EHAB (e.g.
for emergency engine shut- down). For this reason, the “ignition” must be turned on when bleeding the fuel system by means of the presupply pump. 2 1 T ЬV Fi FP 4 3 5 6 1 2 3 5 4 Plug connection 14