The ECM sets DTC P0191 when the average value from fuel rail pressure sensor is out of range of threshold value.
Item | Detecting Condition | Possible Cause | |
Case 1 | DTC Strategy |
•
High pressure sensor output jitter | 1. Poor connection 2. FPS 3. Abnormal fuel pressure 4. Low or no fuel |
Enable Conditions |
•
4.85V < Sensor Output Voltage < 0.20 V | ||
Threshold Value |
•
Sensor output voltage jump time < 0.06 sec. | ||
Diagnostic Time |
•
1 sec. | ||
Case 2 | DTC Strategy |
•
Rationality check negative offset | |
Enable Conditions |
•
Multiplicative Long Term FT < 0.8 %
•
Adaptive Long Term FT < -6.0 %
•
IG ON : Before Engine Start | ||
Threshold Value |
•
Rail Pressure < 0.13 Mpa(1.3 bar/18.85 psi) | ||
Diagnostic Time |
•
6 sec. | ||
Case 3 | DTC Strategy |
•
Rationality check positive offset | |
Enable Conditions |
•
Multiplicative Long Term FT > 1.2 %
•
Adaptive Long Term FT > 6.0 %
•
Soaking Time > 4 hr
•
IG ON : Before Engine Start | ||
Threshold Value |
•
Rail Pressure > 1.3 Mpa(13 bar/188.54 psi) | ||
Diagnostic Time |
•
Immediate | ||
MIL ON Condition |
•
2 driving cycles | ||
※ S1 : upstream oxygen sensor / S2 : downstream oxygen sensor
