VGT(Variable Geometric Turbocharger) is the device which increases the efficiency of turbocharger at low rpm and lasts optimum turbo efficiency at high rpm as varying the cross sectional area through which exhaust gas passes turbocharger impeller. It relieves turbo lag at low speed and increse engine power genetation.
Engine speed, APS signal, MAFS and Boost pressure sensor information is inputted to ECM.
ECM actuates vacuum diafragm which controls exhaust gas line as contrFolling VGT Control solenoid valve duty to maintain optimum state of air compression.
P0299 is set when output value is out of available range(lower than minimum value) for 15 seconds.
Item
Detecting Condition
Possible Cause
DTC Strategy
Signal monitoring
Turbo charger
Intake/exhaust system clogging.
Enable Conditions
Engine running (Engine speed : above 2000rpm , Fuel injection quantity : 15mg/st )
Threshold Value
Output value is output of available range(lower than minimum value).
Diagnostic Time
15000 ms
Fail Safe
Fuel Cut
NO
EGR Off
Fuel Limit
YES
Check Lamp
VGT Control solenoid valve
component resistance
operating Hz
operating duty
14.7 ~ 16.1O (20?)
300Hz
79% at idle, decreases as accelerating
Fig.1) VGT Control solenoid valve output waveform at 79% duty. Duty decreases as boost pressure increases.
Fig.2) VGT Control solenoid valve duty decreased at acceleration.