2. Direct coupling mode

2. Direct coupling mode

This operating mode directly couples the clutch using a rated current when the vehicle has reached the prescribed velocity.

The rated current has three values depending on how hard the accelerator pedal is pressed.

3. Pick-up

To maintain good pick-up characteristics from stationary and low speed driving (up to 7 km/h), including stops during driving in the "D", "L" and "R" modes, a pick-up torque is used to eliminate play. It is created by passing a current (approximately 0.2 A) through the clutch when the accelerator pedal is released.

This pick-up torque is very small compared to that applied in conventional automatic transmissions. To avoid engine slowing when in neutral due to the pick-up torque and also to avoid vehicle creep, the idle speed signal is read by the control unit.

4. Reverse excitation mode

To demagnetise the clutch reverse excitation is used in the following four situations:

1. Selector lever in "N" or "P" position: reverse excitation mode is activated to disengage the clutch.
2. Engine RPM less or equal to 200 RPM. Reverse excitation mode is activated to prevent the engine being started by pushing or towing.
3. For 0.4 - 0.8 seconds after "D" or "P" are selected, reverse excitation mode is activated to facilitate selector lever movement.
4. For approximately 1 second after the accelerator pedal is released during low speed driving the reverse excitation mode is activated to eliminate residual magnetism.

5. Zero mode

If the accelerator is released and the selector lever is in the "D", "L" or "R" position, then the transmission mode changes from "direct coupling" to "pick-up".

During changeover, current to the electromagnetic clutch is cut off.

6. Control of ratio-changing (changeover mode)

This mode allows clutch control to smooth the direct coupling operation, when the selector lever is moved to the "L" position or when it is necessary to accelerate or decelerate from a very low speed, as follows:

• - changing from "D" to "L" the clutch control current is reduced momentarily;
• - when the accelerator pedal is pressed or released the current is reduced momentarily;
• - changing from "starting" to "direct coupling" mode, the variation of the current is controlled so that there is no jerking as the clutch is engaged slowly.