Alfa Romeo MiTo

Functional interaction with other systems

Interaction with engine control

The two systems do not interact while travelling, because the system has no task to perform.

Therefore, data and signals are only exchanged on the network.

Unlike robotised gearbox, when setting off or shifting TCU is master with respect to the engine control unit, and therefore cuts out all the safety conditions that are always managed by the engine. The engine is managed only by the TCU. This control ends after setting off or shifting.

With the introduction of S&S operating logics, further information is exchanged between the transmission and engine control units. All the possible cases are described below. To understand what occurs, we will consider the example of a driver approaching a red light:

• The engine stops when the car stops (the driver is pressing the brake pedal).

• As soon as the driver releases the brake pedal:

• ECU asks TCU to set the transmission in neutral.

• Once the transmission is in neutral, TCU informs ECU that the transmission is secured.

• ECU can restart the engine.

• ECU restarts the engine and at the same time asks TCU to engage the previously released gear.

Interaction with Cruise Control

The CC system is not affected by the presence of the TCT system. There is no function interaction logic with the system.

Safety and functions in case of failure

These strategies manage incorrect commands to prevent potentially dangerous situations or critical conditions for the transmission or the vehicle.

Key lock

Two situations can occur after stopping the engine:

• The driver positions the lever in P

• The driver positions the lever a position other than P

In the first case, the driver can remove the key from the dashboard without any problem; in the second case, the key cannot be removed because the vehicle is not safe. The following operations are possible:

• The driver turns the key again and positions the lever in P

• Despite knowing that vehicle conditions are not safe, the driver removes the ignition key manually, using the mechanical release control.

Obviously, the second option may only be used in genuinely critical cases.

- 67 - Alfa TCT