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 increase engine power generation.
The electronic VGT adapted on R engine is activated by VGT actuator control unit and electronic actuator integrated with DC motor. Engine speed, APS signal, MAFS and Boost pressure sensor data are inputted to ECM. ECM controls VGT actuator control unit to control exhaust gas line as controlling VGT actuator duty to maintain optimum state of air compression. VGT actuator control unit controls DC motor with those signal so that exhaust gas can pass through the vane more or less cross sectional with operating spear gear?outter crank? inner crank?main link? unison ring?inner vane in order.
VGT actuator control unit judges that actuator is faulty by feed back signal of actuator position from turbo charger position sensor. If it is detected, VGT actuator control unit notifies faulty to ECM. The electronic actuator is much faster in operating response and stable in control than vacuum type.
In case of replacing VGT, perform the "COMPONENT CHANGE ROUTINE" procedure with scan tool. If the "COMPONENT CHANGE ROUTINE" procedure has not completed until automatic learning completed, it may cause vehicle performance and exhaust gas problem.
P0299 is set when real boost pressure is 400hpa lower than boost pressure target value lasting 15sec. at above 2000rpm and 15mg/st of fuel injection quantity with driving condition (Over mid-load). In this case, intake air is leaking such as disconnected intercooler hose.
Item
Detecting Condition
Possible Cause
DTC Strategy
Signal monitoring
Turbo charger.
Intake / exhaust line is choked.
Enable Conditions
Engine running ( more than 2000rpm, feul quantity 15mg/st)
Threshold Value
Real boost pressure is 400hpa lower than boost pressure target value lasting 15sec. at above 2000rpm and 15mg/st of fuel injection quantity with driving condition (Over mid-load).
Diagnostic Time
15 sec.
Fail Safe
Fuel cut
NO
-
EGR Off
YES
Fuel Limit
Check
Lamp
ON
Fig.1) VGT actuator duty : 8% (-)duty(304Hz ±3%), 92% (+)duty.
Fig.2) VGT actuator duty at 3200 rpm : 73% (-)duty(304Hz ±3%)