|
DTC Advanced Diagnostics: P0191
DTC P0191:Fuel Rail Pressure Sensor Circuit Range/Performance Problem
General Description
The powertrain control module (PCM) monitors the sensor signal of the fuel rail pressure sensor. Failures in function caused by an open or a short circuits in the electrical circuit can be detected with a pull-up resistor. If the fuel rail pressure sensor is a specified value, the PCM detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
|
Execution |
Continuous |
|
Sequence |
None |
|
Duration |
2 seconds or more*, 0.5 second or more** |
|
DTC Type |
One drive cycle, MIL on | |
|
|
Enable Conditions
Signal stuck check
|
Condition |
Minimum |
Maximum |
|
Engine speed [Engine Speed] |
120 rpm |
4,520 rpm |
|
Fuel rail pressure |
1,000 kPa (10.2 kgf/cm2, 145 psi) |
– |
|
Fuel rail pressure sensor output voltage [Fuel Pressure Converted From PF Sensor] |
– |
4.4 V |
|
Relative fuel mass |
5.02 % |
– |
|
Injection counter |
4 |
– | |
|
|
Offset check
|
Condition |
Minimum |
Maximum |
|
Elapsed time after starting the engine |
3 minutes |
– | |
|
Malfunction Threshold
Any of the conditions is met:
|
|
Signal stuck check
The fuel rail pressure sensor voltage difference between minimum and maximum value over one cycle is 0 V or less. |
|
|
Offset check
The error suspicion is set if the fuel rail pressure is below 130 kPa (1.32 kgf/cm2, 18.8 psi) for at least 0.05 second or greater than 1,300 kPa (13.26 kgf/cm2, 188.6 psi). The PCM confirms the failure if any of the following conditions occur: |
|
|
? |
The multiplicative correction is 0.72 or less or the additive correction is -5.02 % or less of the mixture adaptation. |
|
? |
The multiplicative correction is 1.28 or more or the additive correction is 5.02 % or more of the mixture adaptation. |
|
? |
The fuel rail pressure is greater than 1,300 kPa (13.26 kgf/cm2, 188.6 psi). | |
Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes
|
|
Fuel rail pressure low |
|
|
Fuel rail pressure high |
|
|
Vacuum leaks |
|
|
Fuel rail pressure sensor PF line open |
|
|
Fuel rail pressure sensor PF line short to ground |
|
|
Fuel rail pressure sensor failure |
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, the MIL comes on and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the PCM memory.
Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command. | 