The fuel pressure in the rail is constantly applied to the injectors. Fuel is injected into the combustion chambers upon electrical activation by the DDE control unit.
M47TU:
On the injector high side (P_MVH) all cylinders are combined in a ”block”. The wiring is separate as far as the control unit. Only in the control unit are the wires combined.
Important: If a fault occurs on the high side, the fact that the wires are combined (P_MVH) means that the cause may originate from any of the cylinder leads. In such cases, all injectors will fail.
M57TU:
On the injector high side (P_MVH1-P_MVH6) three cylinders are combined in a ”block”. The wiring is separate as far as the control unit. Only in the control unit are the wires combined.
Important: If a fault occurs on the high side, the fact that the wires are combined (P_MVH) means that the cause may originate from any of the leads of the cylinder bank involved. In such cases, all injectors of the cylinder bank will fail.
M67:
On the high side and low side of the injectors, four cylinders are activated by a DDE control unit. On the high side, the wiring to the control unit is separate. Only in the control unit are the wires combined.
Important: If a fault occurs on the high side, the fact that the wires are combined means that the cause of the fault may originate from any of the leads of the DDE control unit involved. In this case, all the injectors activated by this DDE control unit will fail.
The following faults are monitored on the high side:
The following faults are monitored on the low side of each cylinder:
Consequences:
Depending on number of failed injectors, the engine switches off.