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:

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

?2.
Clear the DTC with the HDS.


?3.
Wait 10 seconds or more.

?4.
Check for Pending or Confirmed DTCs with the HDS.
DTC Description
Confirmed DTC
Pending DTC
P0191 Fuel Rail Pressure Sensor Out of Range
    

Is DTC P0191 indicated?

     
YES
     
     
     
The failure is duplicated. Go to step 2.
     
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.?
2.
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.
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 6.
     
NO
     
     
     
Go to step 3.
3.
Shorted wire check (VCC1 line):

Shorted 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 E (80P)

?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 E (80P): disconnected
Test point 1
Fuel rail pressure sensor 3P connector (female terminals) No. 3:
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
Repair a short in the VCC1 wire between the PCM (E70) and the fuel rail pressure sensor.?
     
NO
     
     
     
The VCC1 wire is not shorted. Go to step 4.
4.
Open wire check (VCC1 line):

Open wire check (VCC1 line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Fuel rail pressure sensor 3P connector: disconnected
 
PCM connector E (80P): disconnected
Test point 1
Fuel rail pressure sensor 3P connector (female terminals) No. 3:
Test point 2
PCM connector E (80P) No. 70


Is there continuity?

     
YES
     
     
     
The VCC1 wire is OK. Go to step 5.
     
NO
     
     
     
Repair an open in the VCC1 wire between the PCM (E70) and the fuel rail pressure sensor.?
5.
Open wire check (SG1 line):

Open wire check (SG1 line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Fuel rail pressure sensor 3P connector: disconnected
 
PCM connector E (80P): disconnected
Test point 1
Fuel rail pressure sensor 3P connector (female terminals) No. 2:
Test point 2
PCM connector E (80P) No. 71


Is there continuity?

     
YES
     
     
     
The SG1 wire is OK. Go to step 8.
     
NO
     
     
     
Repair an open in the SG1 wire between the PCM (E71) 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 E (80P)

?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 E (80P): 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 (E72) and the fuel rail pressure sensor.?
     
NO
     
     
     
The PF wire is not shorted. Go to step 7.
7.
Open wire check (PF line):

Open wire check (PF line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Fuel rail pressure sensor 3P connector: disconnected
 
PCM connector E (80P): disconnected
Test point 1
Fuel rail pressure sensor 3P connector (female terminals) No. 1:
Test point 2
PCM connector E (80P) No. 72


Is there continuity?

     
YES
     
     
     
The PF wire is OK. Go to step 8.
     
NO
     
     
     
Repair an open in the PF wire between the PCM (E72) and the fuel rail pressure sensor.?
8.
Fuel rail pressure sensor check:

Fuel rail pressure sensor check
?1.
Substitute a known-good fuel rail.

?2.
Reconnect all connectors.

?3.
Exit the SCS mode with the HDS.


?4.
Turn the vehicle to the ON mode.

?5.
Clear the DTC with the HDS.


?6.
Wait 10 seconds or more.

?7.
Check for Pending or Confirmed DTCs with the HDS.
DTC Description
Confirmed DTC
Pending DTC
P0191 Fuel Rail Pressure Sensor Out of Range
    

Is DTC P0191 indicated?

     
YES
     
     
     
The fuel rail pressure sensor 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