Fluid Pressure Control

Manual (Steptronic) Mode When in sport mode, if the selector lever is moved to the '+' or '-' positions, the gearbox will automatically enter manual (Steptronic) mode. When the selector lever is moved to the '-' position, it provides a feed to the ATCU (C0932) on a GK wire. When the selector lever is moved to the '+' position, it provides a feed to the ATCU (C0932) on a GB wire. Manual gear changes can now be performed sequentially using the selector lever.

Cruise Control Mode – Td4 The cruise control master switch is located on the centre console, below the radio. When cruise control is activated, the cruise control interface unit (C1959) provides a feed to the ATCU (C0932) on a WU wire. In cruise control mode, the ATCU uses a dedicated gearshift map to control the gearbox and assist the cruise control ECU in maintaining the vehicle speed at the required level.

For more information on cruise control operation, refer to the Cruise Control – Td4 (01MY) section of this manual.  CRUISE CONTROL – Td4 (01MY).

Cruise Control Mode – KV6 The cruise control master switch is located on the centre console, below the radio. When cruise control is activated, the cruise control ECU (C0239) provides a feed to the ATCU (C0932) on a WU wire. In cruise control mode, the ATCU uses a dedicated gearshift map to control the gearbox and assist the cruise control ECU in maintaining the vehicle speed at the required level.

For more information on cruise control operation, refer to the Cruise Control – KV6 section of this manual.  CRUISE CONTROL – KV6.

Hill Descent Control (HDC) Mode In HDC mode, the ATCU applies engine braking to assist the ABS ECU in controlling the vehicles descent. HDC mode is activated if all of the following conditions exist:

The gear selector lever is in position '1' or 'R'. The HDC switch is depressed. The throttle pedal is released.

The ATCU (C0932) communicates with the ABS ECU (C0500) via the CAN-BUS on YB (High) and YN (Low) wires. For more information on the CAN-BUS, refer to the Communication Databuses section of the System Description and Operation Workshop manual.

Fluid Pressure Control

Fluid pressure within the automatic gearbox is controlled by the Line Pressure solenoid. When required, the ATCU (C0932) provides a Pulse Width Modulated (PWM) signal to the Line Pressure solenoid (C0243) on a Y wire. The solenoid (C0243) is earthed via the ATCU (C0932) on an SB wire. For more details on fluid pressure control, refer to the Automatic Gearbox – Jatco section of the System Description and Operation Workshop manual.