Rail Pressure Sensor consists of piezo electric element and detects the inside pressure of Common Rail. ECM decides the amount of fuel injection using Rail Pressure Sensor signal. Besides, Rail Pressure Sensor signal is used as feed back signal for optimum rail pressure control according to various engine condition.
P0190 is set when power supply voltage of Rail Pressure Sensor is measured as below 4.7V or above 5.1V for more than 0.1 sec. This code is due to the 1) short to ground in Rail Pressure Sensor power circuit or 2) short to lines above 5V or 3) the problem relevant to sensor power supply voltage inside of ECM. When P0190 is set, DTC such as APS 2 code - P0220 and Sensor power supply error code - P1524, P1525 could be set simultaneously because Rail Pressure Sensor shares power source with APS 2.
Item
Detecting Condition
Possible Cause
DTC Strategy
? Voltage monitoring
? Rail Pressure Sensor component
? Inside of ECM
Enable Conditions
? Engine run
Threshold Value
? When power supply 2 is below 4.7V or above 5.1V
Diagnostic Time
? 100ms
Fail Safe
Fuel Cut
No
When this code is set with P1524 or P1525, Limp home mode is activated(Engine speed is fixed at 1200RPM )
EGR Off
Fuel Limit
YES
MIL
Sensor Power Supply Voltage 2
Sensor Power Supply Voltage 2 related sensor
4.7~5.1V
APS 2 , Rail Pressure Sensor