Hyundai Venue: Exhaust Emission Control System / CVVT (Continuously Variable Valve Timing) System. Description and operation
Continuous Variable Valve Timing (CVVT) system advances or retards the valve
timing of the intake and exhaust valve in accordance with the ECM control signal
which is calculated by the engine speed and load.
By controlling CVVT, the valve over-lap or under-lap occurs, which makes better
fuel economy and reduces exhaust gases (NOx, HC) and improves engine performance
through reduction of pumping loss, internal EGR effect, improvement of combustion
stability, improvement of volumetric efficiency, and increase of expansion work.
This system consist of the CVVT Oil Control Valve (OCV) which supplies the engine
oil to the cam phaser or runs out the engine oil from the cam phaser in accordance
with the ECM PWM (Pulse With Modulation) control signal, the CVVT Oil Temperature
Sensor (OTS) which measures the engine oil temperature, and the Cam Phaser which
varies the cam phase by using the hydraulic force of the engine oil.
The engine oil getting out of the CVVT oil control valve varies the cam phase
in the direction (Intake Advance/Exhaust Retard) or opposite direction (Intake
Retard/Exhaust Advance) of the engine rotation by rotating the rotor connected
with the camshaft inside the cam phaser.

The CVVT has the mechanism rotating the rotor vane with hydraulic force generated
by the engine oil supplied to the advance or retard chamber in accordance with
the CVVT oil control valve control.

[CVVT System Mode]

(1) Low Speed / Low Load
|
(2) Part Load
|

|

|
(3) Low Speed / High Load
|
(4) High Speed / High Load
|

|

|
Driving Condition
|
Exhaust Valve
|
Intake Valve
|
Valve Timing
|
Effect
|
Valve Timing
|
Effect
|
(1) Low Speed
/Low Load
|
Completely Advance
|
* Valve Under-lap
* Improvement of combustion stability
|
Completely Retard
|
* Valve Under-lap
* Improvement of combustion stability
|
(2) Part Load
|
Retard
|
* Increase of expansion work
* Reduction of pumping loss
* Reduction of HC
|
Retard
|
* Reduction of pumping loss
|
(3) Low Speed
/High Load
|
Retard
|
* Increase of expansion work
|
Advance
|
* Prevention of intake back flow (Improvement of volumetric efficiency)
|
(4) High Speed
/High Load
|
Advance
|
* Reduction of pumping loss
|
Retard
|
* Improvement of volumetric efficiency
|
Description
The catalytic converter of the gasoline engine is a three way catalyst. It oxidizes
carbon monoxide and hydrocarbons (HC), and separates oxygen from the oxides
of nitrogen (NOx)...
Other information:
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 (But CC system
is normal)
Damaged or disconnected bulb of cruise main switch indicator lamp
Repair the harness or replace the part...
Description
The Tire Pressure Monitoring System (TPMS) monitors the pressure and temperature
inside the tire in order to warn the driver of changes in pressure which may
influence the operation of the vehicle. The TPMS control module analyzes wireless
information fro
In other words, the system detects the pneumatic pressure of the tires and warns
the driver of if the pneumatic pressure drops below the standard level...