Operation

Fuel Pump

OPERATION

Td4

General
Feed from the positive battery terminal (C0192) is supplied to fusible link 3, fuse 10, and the main relay (C0632) on an R wire. All are located in the engine compartment fuse box. Operation of the main relay (C0576) is controlled by the Engine Control Module (ECM) (C0603) on a WK wire. For more information on main relay operation, refer to the Engine Management Systems - EDC.

Fuse 10 (C0575) provides a constant battery feed to the inertia switch (C0123) and the fuel pump relay (C0730) on G wires. Fusible link 3 (C0571) provides a constant battery feed to the ignition switch (C0028) on an N wire. When the ignition switch is turned to the 'ignition' position, current flows across the switch (C0028) to fuse 6 of the passenger compartment fuse box (C0588) on a G wire. Fuse 6 (C0581) provides an ignition feed to the ECM (C0603) on a W wire.

Inertia Switch
Fuse 10 of the engine compartment fuse box (C0575) provides a constant battery feed to the inertia switch (C0123) on a G wire. The inertia switch is a normally closed switch. If the inertia switch hasn't been tripped, current flows across the switch (C0123) to the fuel pump relay coil (C0730) on a GU wire.

The inertia switch (C0123) also provides a feed to the Central Control Unit (CCU) (C0428) on a GU wire. For more information on the CCU, refer to the Control Units and the Anti-theft Alarm and Central Door Locking (CDL).

Fuel Pump Relay
The fuel pump relay coil (C0730) receives a feed from the inertia switch (C0123) on a GU wire. The earth path for the relay coil (C0730) is controlled by the ECM (C0331) on a BP wire. The energized fuel pump relay enables a feed from fuse 10 of the engine compartment fuse box (C0575) to flow across the relay switch contacts to the tank mounted low pressure fuel pump (C0114) and the Fuel Injection Pump (FIP) (C0205) on WP wires. Both pumps are earthed on B wires.

K Series and KV6

General
Feed from the positive battery terminal (C0192) is supplied to fusible link 3, fuse 10, and the main relay (C0632) on an R wire. All are located in the engine compartment fuse box. Operation of the main relay (C0576 on K Series vehicles, C0578 on KV6 vehicles) is controlled by the Engine Control Module (ECM) (C0913 on K Series vehicles, C0604 on KV6 NAS vehicles, C0371 on KV6 ROW vehicles) on a WK wire (NG on KV6 NAS vehicles). For more information on main relay operation, refer to the Engine Management Systems - MEMS or Engine Management Systems - Siemens.

Fuse 10 (C0575) provides a constant battery feed to the inertia switch (C0123) on a G wire. Fusible link 3 (C0571) provides a constant battery feed to the ignition switch (C0028) on an N wire. When the ignition switch is turned to the 'ignition' position, current flows across the switch (C0028) to fuse 6 of the passenger compartment fuse box (C0588) on a G wire. Fuse 6 (C0581) provides an ignition feed to the ECM (C0913 on K Series vehicles, C0603 on KV6 NAS vehicles, C0371 on KV6 ROW vehicles) on a W wire.

Inertia Switch
Fuse 10 of the engine compartment fuse box (C0575) provides a constant battery feed to the inertia switch (C0123) on a G wire. The inertia switch is a normally closed switch. If the inertia switch hasn't been tripped, current flows across the switch (C0123) to the fuel pump relay located in the engine compartment fuse box (C0575) on a GU wire.

The inertia switch (C0123) also provides a feed to the Central Control Unit (CCU) (C0428) on a GU wire. For more information on the CCU, refer to the Control Units and the Anti-theft Alarm and Central Door Locking (CDL).

Fuel Pump Relay
The fuel pump relay coil receives a feed from the energized main relay. The earth path for the relay coil (C0575) is controlled by the ECM (C0913 on K Series vehicles, C0331 on KV6 NAS vehicles, C0371 on KV6 vehicles) on a BP wire. The ECM will energize the fuel pump relay when it receives an ignition feed from fuse 6 of the passenger compartment fuse box (C0581) on a W wire.

The energized fuel pump relay (C0572) provides a feed to the fuel pump (C0114) on a WP wire. The pump (C0114) is earthed on a B wire.