Reverse

Reverse

When reverse gear is selected, a main relay feed is able to flow from the transmission selector/inhibit switch (C0244) to the reverse lamp relay (C0935) on an NG wire. The reverse lamp relay (C0935) is earthed on a B wire and controls operation of the reverse lamps. For more information on reverse lamp operation, refer to the Brake and Reverse Lamps section of this manual.  BRAKE AND REVERSE LAMPS.

A main relay feed is also supplied to the ATCU (C0932) and the selector indicator (C0675) on NG wires. The 'R' symbol on the selector housing will now illuminate.

If the vehicle is travelling forwards at greater than 6 mph (10 kph), the ATCU (C0932) provides a feed to the Low Coast solenoid (C0243) on a K wire. The Low Coast solenoid (C0243) is earthed via the ATCU (C0932) on an SB wire. When the Low Coast solenoid receives this feed, it drains the transmission fluid from the reverse clutch, thus preventing reverse gear from being selected.

Neutral

When neutral is selected, a main relay feed is able to flow from the transmission selector/ inhibit switch (C0244) to the ATCU (C0932) and the selector indicator (C0675) on a WU wire. The 'N' symbol on the selector housing will now illuminate.

Drive

When drive is selected, a main relay feed is able to flow from the transmission selector/ inhibit switch (C0244) to the ATCU (C0932) and the selector indicator (C0675) on a WB wire. The 'D' symbol on the selector housing will now illuminate.

When drive is selected, the ATCU (C0932) receives signals from the vehicle speed sensor (C0243) housed within the gearbox on a U wire. The sensor (C0243) is earthed via ATCU (C0932) on a W then KB wire. The ATCU (C0932) also receives a throttle pedal signal from the ECM (C0331 on Td4 and KV6 NAS vehicles, C0371 on KV6 ROW vehicles) via the CAN- BUS on YN (Low) and YB (High) wires. The ATCU uses this information to select the appropriate gear by operating the gearbox shift solenoids as follows:

1st Gear To select first gear, shift solenoid B and shift solenoid C are operated. The ATCU (C0932) will provide a feed to shift solenoid B (C0243) on an O wire. Shift solenoid C (C0243) receives a feed from the ATCU (C0932) on an OU wire.

2nd Gear To select second gear, shift solenoid A and shift solenoid B are operated. The ATCU (C0932) will provide a feed to shift solenoid A (C0243) on an R wire. Shift solenoid B (C0243) receives a feed from the ATCU (C0932) on an O wire.

3rd Gear To select third gear, only shift solenoid B is operated. The ATCU (C0932) will provide a feed to shift solenoid B (C0243) on an O wire.