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 motor, located on the side of the throttle housing, opens and closes the throttle plate for routine driving and cruise conditions.

Power Supply

Fuse 10 (in the under-hood fuse/relay box) supplies battery voltage at all times to the ETCS control relay switch contact in the under-hood fuse/relay box. The PGM-FI main relay 1 supplies battery voltage to the ETCS control relay coil. The PCM grounds the coils of both the ETCS control relay and PGM-FI main relay 1, activating both relays. Activating the ETCS control relay provides battery voltage to the PCM which controls the throttle actuator.

Fuse 7 (in the under-dash fuse/relay box) supplies battery voltage at all times to the control block, which is located in the under-hood fuse/relay box.

Fuse 11 (hot at all times) (in the main under-hood fuse box), and fuse 18 (hot in on or start) (in the under-dash fuse relay box) supply battery voltage to the brake pedal position switch.

System Description

With the shift lever in D or D3, the transmission range switch provides a ground to the PCM, and the cruise control system can be set. It is necessary to accelerate the vehicle to speeds above 25 mph to set the cruise control system.

Pressing the cruise main switch grounds a reference voltage at the gauge control module through G501, and the cruise main indicator illuminates.

Pressing the set switch sends a reference voltage signal to the gauge control module activating the cruise system.

The gauge control module communicates the set signal via multiplex communication lines (F-CAN) to the PCM. Using the vehicle speed input from the TP sensor, the PCM opens and closes the throttle plate maintaining the set vehicle speed.

Pressing the brake pedal supplies a battery voltage input to the PCM through fuse 11 (in the main under-hood fuse box) and removes battery voltage through fuse 18 (in the under-dash fuse relay box) from the PCM.

Pressing the brake pedal deactivates the cruise control system. The PCM communicates the brake pedal pressed information via multiplex communication (F-CAN) lines to the gauge control module.

Pressing the resume switch supplies a reference voltage signal to the gauge control module reactivating the cruise control system to the previously set speed.

Pressing the cancel switch supplies two reference voltage signals to the gauge control module deactivating the cruise system.