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 controlling VGT actuator duty to maintain optimum state of air compression.
P0048 is set when excessive current is detected in VGT actuator control circuit for more than 1 sec.. This code is due to short to battery in control circuit or internal short of VGT actuator component.
Item | Detecting Condition | Possible Cause | |
DTC Strategy | ● Signal monitoring | ● VGT actuator circuit ● VGT actuator component | |
Enable Conditions | ● Engine run(monitoring only performed at actuator operating condition) | ||
Threshold Value | ● Short to battery | ||
Diagnostic Time | ● 1000ms | ||
Fail Safe | Fuel Cut | NO | ● VGT actuator duty is fixed at 31.4%. |
EGR Off | NO | ||
Fuel Limit | YES | ||
Check Lamp | NO |
VGT actuator component resistance | VGT actuator operating Hz | VGT actuator operating duty |
14.7 ~ 16.1Ω (20℃) | 300Hz | 75% at idle, decreases as accelerating |
