DTC Troubleshooting: P0191
DTC P0191: Fuel Rail Pressure Sensor Out of Range
NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description
Confirmed DTC
Pending DTC
P0191 Fuel Rail Pressure Sensor Out of Range
    

1.
Problem verification 1:

Problem verification 1
?1.
Turn the vehicle to the ON mode.

?2.
Check the parameter(s) below with the HDS.
Signal
Threshold
Current conditions
Values
Unit
Values
Unit
INPUT VOLTAGE FROM PF SENSOR
Less than 0.27
V
    

Do the current condition(s) match the threshold?

     
YES
     
     
     
The failure is duplicated. Go to step 3.
     
NO
     
     
     
Go to step 2.
2.
Problem verification 2:

Problem verification 2
?1.
Turn the vehicle to the ON mode.

?2.
Check the parameter(s) below with the HDS.
Signal
Threshold
Current conditions
Values
Unit
Values
Unit
INPUT VOLTAGE FROM PF SENSOR
More than 4.89
V
    

Do the current condition(s) match the threshold?

     
YES
     
     
     
The failure is duplicated. Go to step 7.
     
NO
     
     
     
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the fuel rail pressure sensor and the PCM. If the on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the on-board snapshot.?
3.
Determine possible failure area (PF line, others):

Determine possible failure area (PF line, others)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
Fuel rail pressure sensor 3P connector

?3.
Turn the vehicle to the ON mode.

?4.
Check the parameter(s) below with the HDS.
Signal
Threshold
Current conditions
Values
Unit
Values
Unit
INPUT VOLTAGE FROM PF SENSOR
Less than 0.27
V
    

Do the current condition(s) match the threshold?

     
YES
     
     
     
Go to step 6.
     
NO
     
     
     
Go to step 4.
4.
Determine possible failure area (fuel rail pressure sensor, others):

Determine possible failure area (fuel rail pressure sensor, others)
?1.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
 
Fuel rail pressure sensor 3P connector: disconnected
Test point 1
Fuel rail pressure sensor 3P connector (female terminals) No. 2:
Test point 2
Fuel rail pressure sensor 3P connector (female terminals) No. 3:


Is there about 5.0 V?

     
YES
     
     
     
     
NO
     
     
     
Go to step 5.
5.
Open wire check (VCC1 line):

Open wire check (VCC1 line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Jump the SCS line with the HDS, and wait more than 1 minute.


?3.
Disconnect the following connector.
PCM connector C (51P)

?4.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Fuel rail pressure sensor 3P connector: disconnected
 
PCM connector C (51P): disconnected
Test point 1
Fuel rail pressure sensor 3P connector (female terminals) No. 3:
Test point 2
PCM connector C (51P) No. 41


Is there continuity?

     
YES
     
     
     
The VCC1 wire is OK. The failure is duplicated. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM, then recheck. If DTC P0191 goes away and the PCM was substituted, replace the original PCM.?
     
NO
     
     
     
Repair an open in the VCC1 wire between the PCM (C41) and the fuel rail pressure sensor.?
6.
Shorted wire check (PF line):

Shorted wire check (PF line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Jump the SCS line with the HDS, and wait more than 1 minute.


?3.
Disconnect the following connector.
PCM connector C (51P)

?4.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Fuel rail pressure sensor 3P connector: disconnected
 
PCM connector C (51P): disconnected
Test point 1
Fuel rail pressure sensor 3P connector (female terminals) No. 1:
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
Repair a short in the PF wire between the PCM (C46) and the fuel rail pressure sensor.?
     
NO
     
     
     
The PF wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM, then recheck. If DTC P0191 goes away and the PCM was substituted, replace the original PCM.?
7.
Determine possible failure area (fuel rail pressure sensor, others):

Determine possible failure area (fuel rail pressure sensor, others)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
Fuel rail pressure sensor 3P connector

?3.
Connect terminals A and B with a jumper wire.
Terminal A
Fuel rail pressure sensor 3P connector (female terminals) No. 1:
Terminal B
Fuel rail pressure sensor 3P connector (female terminals) No. 2:

?4.
Turn the vehicle to the ON mode.


?5.
Check the parameter(s) below with the HDS.
Signal
Threshold
Current conditions
Values
Unit
Values
Unit
INPUT VOLTAGE FROM PF SENSOR
More than 4.89
V
    

Do the current condition(s) match the threshold?

     
YES
     
     
     
Go to step 8.
     
NO
     
     
     
8.
Determine possible failure area (SG1 line, others):

Determine possible failure area (SG1 line, others)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Remove the jumper wire from the fuel rail pressure sensor 3P connector.

?3.
Turn the vehicle to the ON mode.

?4.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
 
Fuel rail pressure sensor 3P connector: disconnected
Test point 1
Fuel rail pressure sensor 3P connector (female terminals) No. 2:
Test point 2
Fuel rail pressure sensor 3P connector (female terminals) No. 3:


Is there about 5.0 V?

     
YES
     
     
     
Go to step 10.
     
NO
     
     
     
Go to step 9.
9.
Open wire check (SG1 line):

Open wire check (SG1 line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Jump the SCS line with the HDS, and wait more than 1 minute.


?3.
Disconnect the following connector.
PCM connector C (51P)

?4.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Fuel rail pressure sensor 3P connector: disconnected
 
PCM connector C (51P): disconnected
Test point 1
Fuel rail pressure sensor 3P connector (female terminals) No. 2:
Test point 2
PCM connector C (51P) No. 42


Is there continuity?

     
YES
     
     
     
The SG1 wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM, then recheck. If DTC P0191 goes away and the PCM was substituted, replace the original PCM.?
     
NO
     
     
     
Repair an open in the SG1 wire between the PCM (C42) and the fuel rail pressure sensor.?
10.
Open wire check (PF line):

Open wire check (PF line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Jump the SCS line with the HDS, and wait more than 1 minute.


?3.
Disconnect the following connector.
PCM connector C (51P)

?4.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Fuel rail pressure sensor 3P connector: disconnected
 
PCM connector C (51P): disconnected
Test point 1
Fuel rail pressure sensor 3P connector (female terminals) No. 1:
Test point 2
PCM connector C (51P) No. 46


Is there continuity?

     
YES
     
     
     
The PF wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM, then recheck. If DTC P0191 goes away and the PCM was substituted, replace the original PCM.?
     
NO
     
     
     
Repair an open in the PF wire between the PCM (C46) and the fuel rail pressure sensor.?