Cruise Control: Description and Operation

POWER SUPPLY AND GROUND
When ignition switch is in the ON or START position, power is supplied
^ through 7.5 A fuse [No. (12), located in the fuse block (J/B)]
^ to ASCD hold relay terminal (5) and
^ to ASCD main switch terminal (1).
When ASCD main switch is in the ON position, power is supplied
^ from ASCD main switch terminal (3)
^ to ASCD hold relay terminal (1).
Ground is supplied
^ to ASCD hold relay terminal (2)
^ through body grounds (E5) and (E30).
With power and ground is 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 terminals (2) and (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 turned to OFF position.
During ASCD hold relay is energized power is also supplied to ASCD control unit terminal (5)
^ through ASCD clutch switch and ASCD brake switch (M/T models) or
^ through ASCD brake switch, ASCD hold relay and park/neutral position relay (A/T models). Ground is supplied
^ to ASCD control unit terminal (3)
^ through body grounds (M13), (M73) and (M111).

OPERATION
Set operation
To activate the ASCD, all of following conditions must exist.
^ Power supply to ASCD control unit terminal (4)
^ Power supply to ASCD control unit terminal (5) [Brake and clutch (M/T models) pedal is released and A/T selector lever is in other than P and N position (A/T models).]
^ Vehicle speed is greater than 48 kph (30 mph). (Signal from combination meter) When the SET/COAST switch is depressed, power is supplied
^ from ASCD steering switch terminal (2)
^ to ASCD control unit terminal (2).
And then ASCD pump is activated to control throttle wire and ASCD control unit supply power to combination meter terminal (8) to illuminate CRUISE indicator.

A/T overdrive control during cruise control driving (An models)
When the vehicle speed is approximately 8 kph (5 mph) below set speed, a signal is sent
^ from ASCD control unit terminal (12)
^ to TCM (transmission control module) terminal (24).
When this occurs, the TCM (transmission control module) cancels overdrive.
After vehicle speed is approximately 3 km/h (2 MPH) above set speed, overdrive is reactivated. Coast operation
Coast Operation
When the SET/COAST switch is depressed during cruise control driving, ASCD actuator returns the throttle cable to decrease vehicle set speed until the switch is released. And then ASCD will keep the new set speed.

Accel operation
When the RESUME/ACCEL switch is depressed, power is supplied
^ from ASCD steering switch terminal (3)
^ to ASCD control unit terminal (1).
If the RESUME/ACCEL switch is depressed during cruise control driving, ASCD actuator pulls the throttle cable to increase the vehicle speed until the switch is released or vehicle speed is reached to maximum controlled speed by the system. And then ASCD will keep the new set speed.

Cancel operation
When any of following condition exists, cruise operation will be canceled.
^ CANCEL switch is depressed. (Power supply to ASCD control unit terminals (1) and (2)
^ Brake pedal is depressed. (Power supply to ASCD control unit terminal (11) from stop lamp switch)
^ Brake or clutch (M/T models) pedal is depressed or A/T selector lever is shifted to P or N position (A/T models). (Power supply to ASCD control unit terminal (5) is interrupted.)
If MAIN switch is turned to OFF during ASCD is activated, all of ASCD operation will be canceled and vehicle speed memory will be erased.

Resume operation
When the RESUME/ACCEL switch is depressed after cancel operation other than depressing MAIN switch is performed, vehicle speed will return to last set speed. To resume vehicle set speed, vehicle condition must meet following conditions.
^ Brake pedal is released.
^ Clutch pedal is released (M/T models).
^ A/T selector lever is in other than P and N position (A/T models).
^ Vehicle speed is greater than48 km/h (30 MPH).




ASCD PUMP OPERATION
The ASCD pump consists of a vacuum motor, an air valve and a release valve. When the ASCD activates, power is supplied
^ from terminal (8) of ASCD control unit
^ to ASCD pump terminal (1).
Ground is supplied to vacuum motor, air valve and release valve from ASCD control unit depending ON the operated condition as shown in the diagram.
The pump is connected to ASCD actuator by vacuum hose. When the ASCD pump is activated, the ASCD pump vacuum the diaphragm of ASCD actuator to control throttle cable.