Cruise Control: Description and Operation

Cruise Control

How the Circuit Works

The vehicle does not use a throttle cable or cruise control actuator to maintain the vehicle speed during the cruise control mode. A throttle actuator control motor, located on the side of the throttle housing, opens and closes the throttle plate for routine driving and cruise conditions.

Power Supply

Fuse 21 (in the under-hood fuse/relay box) provides battery voltage at all times to the ETCS control relay contacts. Fuse 19 (in the under-hood fuse/relay box) provides battery voltage at all times to the PGM-FI main relay. Fuse 12 (in the under-hood fuse/relay box) provides battery voltage at all times to the MICU and brake pedal position switch (normally open contacts).

With the ignition ON (II), fuse 3 (in the under-dash fuse/relay box) provides battery voltage to the brake pedal position switch (normally closed contacts) and fuse 10 (in the under-dash fuse/relay box) provides battery voltage to the gauge control module.

System Description

Pressing the main switch provides a ground signal to the gauge control module, illuminating the cruise control main switch indicator LED. The PCM receives a ground signal when the shift lever is in D, 2 or 1, which enables the cruise control.

Pressing the set switch sends a voltage signal to the gauge control module. The gauge control module illuminates the cruise control indicator LED. The gauge control module communicates the set signal via multiplex communication lines to the PCM. The PCM obtains the vehicle speed input from the output shaft (countershaft) speed sensor and sends signals to, and receives signals from, the TP sensor to control the throttle actuator and maintain the set speed.

Pressing the brake pedal sends a battery voltage input through fuse 12 (in the under-hood fuse/relay box) to the PCM and removes the battery voltage input through fuse 3 (in the under-dash fuse/relay box). The PCM communicates the brake pedal pressed information via multiplex communication lines to the gauge control module, turning off the cruise control indicator LED. The PCM also removes the cruise control system's control of the throttle.

Pressing the resume switch sends a voltage signal to the gauge control module. The gauge control module illuminates the cruise control indicator LED. The gauge control module communicates the resume signal via multiplex communication lines to the PCM. The PCM obtains the vehicle speed input from the output shaft (countershaft) speed sensor and sends signals to, and receives signals from, the TP sensor to control the throttle actuator and maintain the previously set speed.

Pressing the cancel switch sends two voltage signals to the gauge control module. The gauge control module turns off the cruise control indicator LED. The gauge control module communicates the cancel signal via multiplex communication lines to the PCM. The PCM uses the information to remove the cruise control system's control of the throttle.