System Description

When the ignition switch is in the ON or START position, power is supplied:
^ through 10 A fuse (No. (29), located in the fuse block)
^ to Automatic Speed Control Device (ASCD) main switch terminal (1)
^ to ASCD hold relay terminal (5) and
^ to ASCD cancel switch terminal (1).
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 (2).
Ground is supplied:
^ to ASCD hold relay terminal (1)
^ through body grounds (E3), (E14) and (E53).
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).
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 (M5), (M78) and (M123).

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 and
^ ASCD cancel switch.
A vehicle speed input is supplied:
^ to ASCD control unit terminal (7)
^ from terminal (31) of the combination meter.
Power is supplied at all times:
^ through 15 A fuse (No. (22), located in the fuse block)
^ 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 15 A fuse (No. (44),located in the fuse and fusible link box)
^ to horn relay terminal (2)
^ through terminal (1) of the horn relay
^ to ASCD steering switch terminal (6).
When the SET/COAST button is depressed, power is supplied:
^ from terminal (4) of the ASCD steering switch
^ to ASCD control unit terminal (2).
When the RESUME/ACCEL button is depressed, power is supplied:
^ from terminal (5) 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:
^ from ASCD cancel switch terminal (2)
^ to ASCD hold relay terminal (7)
^ through ASCD hold relay terminal (6)
^ to inhibitor relay terminal (4)
^ through inhibitor relay terminal (3)
^ to ASCD control unit terminal (5).
Power is interrupted when:
^ the selector lever is placed in ("P") or ("N") 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 (37) and
^ to A/T control unit terminal (37).
Ground is supplied:
^ to combination meter terminal (12)
^ through body grounds (M5), (M78) and (M123).
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).
When this occurs, overdrive is cancelled.