Cruise Control System

Description and Operation

Description

The cruise control system is turned on with the cruise control "ON/OFF" main switch located on the right side of the steering column. The system provides cruise, coast, acceleration and resume functions. It also has a protective cutout that operates when the brake pedal or shift lever is operated. The ECM is the control module for this system. The main components of the cruise control system are the mode control switches, the transmission range switch, the brake switch, the vehicle speed sensor, the engine ECM and the ETS, which is connected to the throttle body. The ECM contains a low-speed limit that prevents the system from engaging below the minimum speed of 40 km/h. Controller operation is governed by the mode switches located on the steering wheel. The transmission range switch and the brake switch are designed to cancel the cruise control system. The switches are located on the brake pedal bracket and the transmission. When the brake pedal is depressed or the selector lever is moved, the cruise control system is electrically disengaged and the throttle valve returns to its initial position.

CRUISE main ON/OFF switch

The cruise control system is turned on by pressing the cruise "ON/OFF" button on the main switch. Pressing the cruise main switch "ON/OFF" again releases the accelerator, clears the cruise control speed memory and switches the vehicle to non-cruise mode.

SET/– switch

The "SET/–" switch, located on the right side of the steering column, has two functions. Set function - press the "SET/–" switch and release it at the desired speed. The SET indicator in the instrument cluster will illuminate. Release the accelerator pedal. The desired speed will be maintained automatically. Coast function - press and hold the "SET/–" switch while cruise control is engaged. The vehicle will decelerate gradually. Release the switch at the desired speed. The desired speed will be maintained. Press the "SET/–" switch and release it quickly. The cruise speed will decrease by 2 km/h or 1 mph each time.

RES/+ switch

The "RES/+" switch, located on the right side of the steering column, has two functions. Resume function - If any method other than the cruise "ON/OFF" main switch was used to temporarily cancel the cruise speed and the system is still active, the most recently set speed will automatically resume when the "RES/+" switch is pressed. However, it will not resume if the vehicle speed has dropped below approximately 40 km/h. Acceleration function - press and hold the "RES/+" switch while cruise control is engaged. The vehicle will accelerate gradually. Release the switch at the desired speed. The desired speed will be maintained. Press the "RES/+" switch and release it quickly. The cruise speed will increase by 2 km/h or 1 mph each time.

CANCEL switch

The cruise control system is temporarily disengaged by pressing the CANCEL switch. The cruise speed canceled by this switch can be restored by pressing the RES/+ switch.

Circuit Diagrams

System Block Diagram

Components and Function Schematic

Component		Function
Vehicle speed sensor, ESP/ABS control module		Converts vehicle speed into a pulse signal.
ECM		Receives signals from sensors and switches.
Cruise Control Indicator		Illuminates when the CRUISE main switch is turned on (built into cluster)
Cruise Control Switches	CRUISE switch	Cruise control power switch.
	RES (+) switch	Controls the cruise control functions using the Resume/Accel switch (Set/Coast switch).
	SET (–) switch
Cancel switches	Cancel switch	Sends cancel signals to the ECM.
	Brake Pedal Switch
	Transmission range switch (A/T)
ETC Motor		Controls the throttle valve opening as set by the ECM.

* ETC Motor: Electronic Throttle Control motor

Troubleshooting

Symptom Troubleshooting Tables

Symptom Troubleshooting 1

Symptom 2

Symptom of Malfunction	Probable Cause	Remedy
Vehicle set speed fluctuates greatly up or down "Hunting" (repeated alternating acceleration and deceleration) occurs after setting	Vehicle speed sensor circuit malfunction	Repair the vehicle speed sensor system or replace the component.
	Engine control module malfunction	Check the input and output signals at the ECM.

Symptom 3

Symptom of Malfunction	Probable Cause	Remedy
CC system does not cancel when the brake pedal is depressed	Brake switch wiring is damaged or disconnected	Repair the harness or replace the brake pedal switch.
	ECM signal malfunction	Check the input and output signals at the ECM.

Symptom 4

Symptom of Malfunction	Probable Cause	Remedy
The CC system is not cancelled when the shift lever is moved to the "N" position (however, it is cancelled when the brake pedal is pressed).	Inhibitor switch input circuit wiring is damaged or disconnected.	Repair the harness or repair or replace the inhibitor switch.
	Incorrect inhibitor switch adjustment
	ECM signal malfunction	Check the input and output signals at the ECM.

Symptom 5

Symptom of Malfunction	Probable Cause	Remedy
Cannot decelerate (coast) using the "SET/–" switch.	Temporary damage or disconnection of the SET/– switch input circuit wiring	Repair the harness or replace the "SET/–" switch.
	ECM signal malfunction	Check the input and output signals at the ECM.

Symptom 6

Symptom of Malfunction	Probable Cause	Remedy
Cannot accelerate or resume speed using the "RES/+" switch.	Damaged or disconnected wiring, or a short circuit, or the input circuit of the "RES/+" switch	Repair the harness or replace the "RES/+" switch.
	ECM signal malfunction	Check the input and output signals at the ECM.

Symptom 7

Symptom of Malfunction	Probable Cause	Remedy
The CC system can be set while driving at a speed below 40 km/h, or there is no automatic cancellation at this speed.	Vehicle speed sensor circuit malfunction	Repair the vehicle speed sensor system or replace the component.
	ECM signal malfunction	Check the input and output signals at the ECM.

Symptom 8

Symptom of Malfunction	Probable Cause	Remedy
Cruise control main switch indicator lamp does not illuminate (but the CC system operates normally)	Damaged or disconnected cruise control main switch indicator lamp bulb	Repair the harness or replace the component.
	Harness is damaged or disconnected