Automatic Speed Control Device (ASCD)

When the ignition switch is in the ON or START position, power is supplied:
- through 7.5 A fuse [No. 5, located in the fuse block (J/B)]
- to ASCD main switch terminal 1.
- to ASCD hold relay terminal 5.
- to ASCD brake switch terminal 1.
- through ASCD brake switch terminal 2.
- to ASCD hold relay terminal 7.
When ASCD main switch is in the ON position, power is supplied:
- from ASCD main switch terminal 3.
- to ASCD hold relay terminal 2.
Ground is supplied:
- to ASCD hold relay terminal 1
- through body grounds M14 and M68.
With power and ground supplied, ASCD hold relay is energized, and then power is supplied:
- from ASCD hold relay terminal 3.
- to ASCD control unit terminal 4 and
- to ASCD main switch terminal 2.
After the ASCD main switch is released, power remains supplied:
- to the coil circuit of ASCD hold relay
- through ASCD main switch terminal 3.
This power supply is kept until one of following conditions exists:
- Ignition switch is returned to the ACC or OFF position
- ASCD main switch is pushed to OFF position.
When ASCD hold relay is energized, power is also supplied to ASCD control unit terminal 5:
- through ASCD brake switch and
- ASCD clutch switch (with M/T) or
- ASCD relay (with A/T).
Ground is supplied:
- to ASCD control unit terminal 3.
- through body grounds M14 and M68.

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
- ASCD clutch switch (with M/T) or
- ASCD relay (with A/T)
- ASCD brake switch.
A vehicle speed input is supplied:
- to ASCD control unit terminal 7.
- from terminal 34 of the combination meter.
Power is supplied at all times:
- to stop lamp switch terminal 1.
- through 10 A fuse [No.22, located in the fuse block (J/B)].
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 10 A fuse [No. 32, 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 3.
When the SET/COAST switch is depressed, power is supplied:
- from terminal 2 of the ASCD steering switch
- to ASCD control unit terminal 2.
When the RESUME/ACCEL switch is depressed, power is supplied:
- from terminal 1 of the ASCD steering switch
- to ASCD control unit terminal 1.
When the ASCD CANCEL switch is depressed, power is supplied:
- to ASCD control unit terminals 1 and 2.
When the system is activated, power is supplied:
- from ASCD clutch switch terminal 2 (with M/T) or
- from ASCD relay terminal 4 (with A/T)
- to ASCD control unit terminal 5.
Power is interrupted when:
- the ASCD main switch is turned to OFF
- the ASCD clutch switch is depressed (with M/T)
- the A/T selector lever is placed in P or N (with A/T) or
- the ASCD brake switch is depressed.

OUTPUTS
The ASCD actuator controls the throttle drum via the ASCD wire based on inputs from the ASCD control unit.
The ASCD pump 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 pump terminal 1.
Ground is supplied to the vacuum motor:
- from terminal 9 of the ASCD control unit
- to ASCD pump terminal 2.
Ground is supplied to the air valve:
- from terminal 10 of the ASCD control unit
- to ASCD pump terminal 3.
Ground is supplied to the release valve:
- from terminal 14 of the ASCD control unit
- to ASCD pump terminal 4.
When the system is activated, power is supplied:
- from terminal 13 of the ASCD control unit
- to combination meter terminal 30.
Ground is supplied:
- to combination meter terminal 33.
- through body grounds M14 and M68.
With power and ground supplied, the CRUISE indicator illuminates.
When vehicle speed is approximately 8 kph (5 MPH) below set speed on A/T models, ground is supplied:
- from terminal 12 of the ASCD control unit
- to transmission control module terminal 24.
When this occurs, the transmission control module cancels overdrive.
When vehicle speed is approximately 3 kph (2 MPH) above set speed, overdrive is reactivated.