Cruise Control Switch: Description and Operation

Switches, Overview







The cruise control is operated by means of the switch on the direction indicator control stalk (switch 141). The starting position for the switch is called the neutral position. On activation of the cruise control the switch returns to the starting position, that is to say the switch is spring-loaded to the neutral position after activation.
The switch is supplied with current from the +54 circuit via fuse 22 and has three outputs to the control module (see image above).

The various switch positions are:

Neutral position
The switch is spring-loaded to the neutral position. None of the switch's terminals (A, B and C) is live.

ON/OFF
When the switch is moved to the extreme left, terminals A, B and C are supplied with current. The ON/OFF position has two functions, alternately ON and OFF.

CANCEL
Switch terminals B and C are supplied with current between the neutral position and ON/OFF. This position has the same function as when the brake or clutch pedal is depressed, i.e. the cruise control is disengaged although the set speed is retained in the memory.

RES/-
When the switch is moved from the neutral position to the right, terminal C is supplied with current. This position has three functions:
1 Engages the cruise control and stores the current speed in the memory if no speed has been stored earlier.
2 Engages the cruise control if a speed is stored in the memory but the cruise control function has been interrupted with CANCEL, the brake pedal or the clutch pedal.
3 If this position is selected while the cruise control is active, the speed will drop. When the button returns to the neutral position the current speed will be stored and cruise control is resumed.

If this position is selected for less than about 0.3 seconds (brief pressure on the button), the requested speed will be reduced in increments of 1.6 km/h (1 mph).

SET/+
At the end of the direction indicator control stalk is a spring-loaded push-button. When it is pressed, terminal B will be supplied with current. This position has two functions:
1 Engages the cruise control and stores the current speed in the memory, regardless of whether another speed is already stored in the memory.
2 Keeping the button depressed increases the speed. When the button is released the current speed will be stored and the cruise control continues to be operative at this speed.

If the button is pressed for less than 0.3 seconds, speed will be increased in increments of 1.6 km/h (1 mph).
The following conditions must be fulfilled before the cruise control system can be activated:

Switch







Neutral position:
The neutral position is the switch's starting position before the cruise control is activated. In the neutral position, terminals A, B and C are not supplied with current.







CANCEL:
Immediately to the left of the spring-loaded neutral position is the CANCEL position.
When the cruise control system is activated (ON position), the CRUISE lamp goes out as an acknowledgement that the switch has been moved to the CANCEL position. Accordingly, the CRUISE lamp is out when CANCEL is active and comes on again when the switch is released.
In the CANCEL position, current is supplied to control module terminals B and C and the cruise control is disengaged.







ON/OFF:
To the extreme left of the spring-loaded neutral position is the ON/OFF position.
In the ON/OFF position, current is supplied to control module terminals A, B and C.
The ON/OFF position has two functions: the first time the button is activated it is in the ON position, the second time it is in the OFF position, and so on.
If none of the terminals is supplied with current, ON/OFF will be inoperative.







RES/-:
To the right of the spring-loaded neutral position is the RESUME (RES/-) position. Current is supplied to control module terminal C.

This position has three functions:
1 When the cruise control is activated and its memory is empty, this position can be used as a SET function, i.e. the current speed is saved in the memory.







2 After activation of the brake or clutch pedal, the cruise control can be returned to the original speed by pressing RES/.







3 If the button is held in the RES/- position for a longer period, speed will gradually decrease. When the button is released, the new speed will be saved in the memory. Pressing the button briefly reduces the speed in steps of 1.6 km/h (1 mph).







SET/+:
The spring-loaded SET/+ button is located on the end of the direction indicator control stalk. Current is supplied to control module terminal B when this button is pressed.

This position has two functions:
1 When the cruise control is activated and the SET/+ button is pressed, the current speed of the car will be stored in the cruise control memory.







2 Pressing the SET/+ button for a longer period causes the speed to increase successively. When the button is released the new speed will be saved in the memory. Pressing the button briefly causes speed to increase in steps of 1.6 km/h (1 mph).