Hyundai Elantra AD: Cruise Control System - Engine Electrical System - Hyundai Elantra AD 2017-2020 Service ManualHyundai Elantra AD: Cruise Control System

Description and Operation

Cruise Control
The cruise control system is engaged by the cruise "ON/OFF" main switch located on the right-hand side of steering wheel column. The system has the capability to cruise, coast, accelerate and resume speed.

It also has a safety interrupt, engaged upon depressing brake or shifting select lever.

The ECM is the control module for this system. The main components of cruise control system are mode control switches, transmission range switch, brake switch, vehicle speed sensor, ECM and ETS motor that connect throttle body.

The ECM has a low speed limit that prevents system engagement below a minimum speed of 40km/h (25mph).

The operation of the controller is controlled by mode control switches located on steering wheel.

Transmission range switch and brake switch are provided to disengage the cruise control system. The switches are on brake pedal bracket and transmission. When the brake pedal is depressed or select lever shifted, the cruise control system is electrically disengaged and the throttle is returned to the idle position.

Cruise main switch (ON/OFF)

The cruise control system is engaged by pressing the cruise "ON/OFF" main switch. Pressing the cruise "ON/OFF" main switch again releases throttle, clears cruise memory speed, and puts vehicle in a non-cruise mode.

Set/Coast switch (SET/–)

The "SET/–" switch located on right-hand side of steering wheel column, has two functions.

The set function - Push the "SET/–" switch and release it at the desired speed. The SET indicator light in the instrument cluster will illuminate. Release the accelerator pedal. The desired speed will automatically be maintained.

The coast function - Push the "SET/–" switch and hold it when the cruise control is on. The vehicle will gradually slow down. Release the switch at the desired speed. The desired speed will be maintained.

Push the "SET/–" switch and release it quickly. The cruising speed will decrease by 2.0km/h (1.2mph).

Resume/Accel switch (RES/+)

The "RES/+" switch located on right-hand side of steering wheel column, has two functions.

The resume function - If any method other than the cruise “ON/OFF” main switch was used to cancel cruising speed temporarily and the system is still activated, the most recent set speed will automatically resume when the "RES/+" switch is pushed. It will not resume, however, if the vehicle speed has dropped below approximately 40km/h (25mph).

The accel function - Push the "RES/+" switch and hold it when the cruise control is on. The vehicle will gradually accelerate. Release the switch at the desired speed. The desired speed will be maintained.

Push the "RES/+" switch and release it quickly. The cruising speed will increase by 2.0km/h (1.2mph).

Cancel switch (CANCEL)

The cruise control system is temporarily disengaged by pushing the "CANCEL" switch.

Cruise speed canceled by this switch can be recovered by pushing the "RES/+" switch.

Schematic Diagrams

System Block Diagram

Component Parts And Function Outline
Component part
Function
Vehicle-speed sensor, ESP/ABS Control Module
Converts vehicle speed to pulse.
ECM
Receives signals from sensor and control switches.
Cruise control indicator
Illuminate when CRUISE main switch is ON (Built into cluster)
Cruise Control switches
CRUISE switch
Switch for automatic speed control power supply.
RES+ switch
Controls automatic speed control functions by Resume/Accel switch (Set/Coast switch)
SET- switch
Cancel switches
Cancel switch
Sends cancel signals to ECM.
Brake-pedal switch
Transaxle range switch (A/T)
ETC motor
Regulates the throttle valve to the set opening by ECM.

* ETC Motor : Electronic Throttle Control Motor

Troubleshooting

Trouble Symptom Charts
Trouble Symptom 1

Trouble Symptom 2
Trouble symptom
Probable cause
Remedy
The set vehicle speed varies greatly upward or downward
"Surging" (repeated alternating acceleration and deceleration) occurs after setting
Malfunction of the vehicle speed sensor circuit
Repair the vehicle speed sensor system, or replace the part
Malfunction of ECM
Check input and output signals at ECM

Trouble Symptom 3

Trouble symptom
Probable cause
Remedy
The CC system is not canceled when the brake pedal is depressed
Damaged or disconnected wiring of the brake pedal switch
Repair the harness or replace the brake pedal switch
Malfunction of the ECM signals
Check input and output signals at ECM

Trouble Symptom 4

Trouble symptom
Probable cause
Remedy
The CC system is not canceled when the shift lever is moved to the "N" position (It is canceled, however, when the brake pedal is depressed)
Damaged or disconnected wiring of inhibitor switch input circuit
Repair the harness or repair or replace the inhibitor switch
Improper adjustment of inhibitor switch
Malfunction of the ECM signals
Check input and output signals at ECM

Trouble Symptom 5

Trouble symptom
Probable cause
Remedy
Cannot decelerate (coast) by using the "SET/–" switch
Temporary damaged or disconnected wiring of "SET/–" switch input circuit
Repair the harness or replace the "SET/–" switch
Malfunction of the ECM signals
Check input and output signals at ECM

Trouble Symptom 6

Trouble symptom
Probable cause
Remedy
Cannot accelerate or resume speed by using the "RES/+" switch
Damaged or disconnected wiring, or short circuit, or "RES/+" switch input circuit
Repair the harness or replace the "RES/+" switch
Malfunction of the ECM signals
Check input and output signals at ECM

Trouble Symptom 7

Trouble symptom
Probable cause
Remedy
CC system can be set while driving at a vehicle speed of less than 40km/h (25mph), or there is no automatic cancellation at that speed
Malfunction of the vehicle-speed sensor circuit
Repair the vehicle speed sensor system, or replace the part
Malfunction of the ECM signals
Check input and output signals at ECM

Trouble Symptom 8

Trouble symptom
Probable cause
Remedy
The cruise main switch indicator lamp does not illuminate (although CC system is normal)
Damaged or disconnected bulb of cruise main switch indicator lamp
Repair the harness or replace the part.
Harness damaged or disconnected

Cruise Control Switch Components and Components Location

Components

1. Remote control switch (LH)
2. Remote control switch (RH)

Cruise Control Switch Schematic Diagrams

Circuit Diagram

Cruise Control Switch Repair procedures

Removal
1. Turn the ignition switch OFF and disconnect the battery negative (-) cable.
2. Remove the steering wheel assembly.
3. Remove the screws from the steering back cover (A).

4. Remove the steering remote control connector (A).

5. Remove the steering remote control (A) after loosening the screws.

Installation
1. Install the steering wheel remote controll and cover after connecting the connector.
2. Install the steering wheel and driver airbag module.
3. Connect the negative (-) battery terminal.
Inspection
1. Remove the cruise control switch.
2. Measure the resistance between terminals on the control switch when each function switch is ON (and switch is depressed).

Switch
Connectorterminal
Resistance(±5%)
CANCEL
2 ~ 5
330 ?
SET -
2 ~ 5
550 ?
RES +
2 ~ 5
880 ?
CRUISE
2 ~ 5
1.44 k?

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