Cruise Control: Description and Operation

When the ignition switch is in the ON or START position, power is supplied:
^ through 7.5 A fuse (No. (7) located in the fuse block [HEC])
^ to Automatic Speed Control Device main switch terminal (1) and
^ to ASCD hold relay terminal (5).
When ASCD main switch is in the ON position, power is supplied:
^ from terminal (2) of the ASCD main switch
^ to ASCD control unit terminal (4) and
^ from terminal (3) of the ASCD main switch
^ to ASCD hold relay terminal (1).
Ground is supplied:
^ to ASCD hold relay terminal (2)
^ through body grounds (M43),(M44) and ((M60).
With power and ground supplied, the ASCD hold relay is activated, and power is supplied:
^ from terminal (3) of the ASCD hold relay
^ to ASCD control unit terminal (4) and
^ to ASCD clutch pedal position switch terminal (1) (M/T models) or
^ to inhibitor relay terminal (3) (A/T models).
Power remains supplied to ASCD control unit terminal (4) when the ASCD main switch is released to the N (neutral) position.
Ground is supplied:
^ to ASCD control unit terminal (3)
^ through body grounds (M43), (M44) and ((M60).

Inputs
At this point, the system is ready to activate or deactivate, based on inputs from the following:
^ speedometer in the combination meter
^ stop lamp switch
^ ASCD steering switch
^ inhibitor relay (A/T models)
^ ASCD clutch pedal position switch (M/T models)
^ ASCD cancel switch.
A vehicle speed input is supplied:
^ to ASCD control unit terminal (7)
^ from terminal (23) [(21)] of the combination meter.
Power is supplied at all times:
^ through 15 A fuse (No. (14), located in the fuse block [HEC])
^ to stop lamp switch terminal (1).
When the brake pedal is depressed, power is supplied:
^ from terminal (2) of the stop lamp switch
^ to ASCD control unit terminal (11).
Power is supplied at all times:
^ through 1O A fuse (No. (42), located in the fusible link and fuse box)
^ to horn relay terminal (2)
^ through terminal (1) of the horn relay
^ to ASCD steering switch terminal (12).
When the SET/COAST button is depressed, power is supplied:
^ from terminal (14) of the ASCD steering switch
^ to ASCD control unit terminal (2).
When the RESUME/ACCEL button is depressed, power is supplied:
^ from terminal (13) of the ASCD steering switch
^ to ASCD control unit terminal (1).
When the CANCEL button is depressed, power is supplied:
^ to ASCD control unit terminals (1) and (2).
When the system is activated, power is supplied:
^ to ASCD control unit terminal (5).
Power is interrupted when:
^ the shift lever is placed in "P" or "N" (A/T models)
^ the clutch pedal is depressed (M/T models) or
^ the brake pedal is depressed.

Outputs
The ASCD actuator controls the throttle drum via the ASCD wire based on inputs from the ASCD control unit. The ASCD actuator consists of a vacuum motor, an air valve, and a release valve.
Power is supplied:
^ from terminal (8) of the ASCD control unit
^ to ASCD actuator terminal (1).
Ground is supplied to the vacuum motor:
^ from terminal (9) of the ASCD control unit
^ to ASCD actuator terminal (4)
Ground is supplied to the air valve:
^ from terminal (10) of the ASCD control unit
^ to ASCD actuator terminal (2).
Ground is supplied to the release valve:
^ from terminal (14) of the ASCD control unit
^ to ASCD actuator terminal (3).
When the system is activated, power is supplied:
^ from terminal (13) of the ASCD control unit
^ to combination meter terminal (25) [(26)] and
^ to A/T control unit terminal (37) (A/T models with SR engine).
Ground is supplied:
^ to combination meter terminal (27) [(28)]
^ through body grounds (M43), (M44) and (M60).
With power and ground supplied, the CRUISE indicator illuminates.
When the RESUME/ACCEL button is depressed() a signal is sent:
^ from terminal (12) of the ASCD control unit
^ to A/T control unit terminal (40) (A/T models with SR engine), or.
^ to A/T control valve terminal (2) (A/T models with GA engine). When this occurs, overdrive is cancelled.

*: Terminal numbers in [] are for models without tachometer.