RPS(Rail Pressure Sensor), consists of piezzo electric element, measures rail pressure inside of common rail.
ECM determines optimum fuel injection quantity at specific engine condition based on RPS signal. RPS signal is also used as rail pressure regualtor feed back signal in order to achieve optimum rail pressure at certain engine condition.
1. Connector
2. Measurement circuit
3. Sensor element(diaphragm)
4. Rail pressure
5. Fuel rail
P0191 is set when RPS output voltage is below the minimum value of 189mV for more than 0.5 sec.. This code is due to the sensor.
Item | Detecting Condition | Possible Cause | ||
DTC Strategy |
•
Pressure monitoring |
•
RPS circuit
•
RPS component | ||
Enable Conditions |
•
Engine running | |||
Threshold Value |
•
Output value from AD convertor out of available range. | |||
Diagnostic Time |
•
300ms | |||
Fail Safe | Fuel cut | NO | ||
EGR Off | NO | |||
Fuel Limit | YES | |||
Check Lamp | YES | |||
Fig 1) This waveform shows the rise of RPS output voltage at rapid acceleration.
