ECD SYSTEM, Diagnostic DTC:P0191

DTC Code	DTC Name
P0191	Fuel Rail Pressure Sensor "A" Circuit Range/Performance

DESCRIPTION

Refer to DTC P0192.

For information on the fuel system, refer to System Description.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

P0191

Fuel Rail Pressure Sensor "A" Circuit Range/Performance

Either condition is met (3 trip detection logic):

Fuel pressure sensor feedback value exceeds upper limit for 0.1 seconds.
Fuel pressure sensor feedback value falls below lower limit for 0.1 seconds.

Open or short in fuel pressure sensor circuit
Fuel pressure sensor
ECM

Comes on

DTC stored

WIRING DIAGRAM

Refer to DTC P0192.

CAUTION / NOTICE / HINT

Note

When replacing the ECM and/or injector assembly, the ECM needs registration and initialization.

Tech Tips

When the ECM must be replaced, before replacing the ECM, perform the "Learning Values Save" function using the GTS. Then after installing the new ECM, perform all of the initialization/registrations for the "Learning Values Write" function by following the instructions shown on the GTS display.
Read freeze frame data using the GTS. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, and other data from the time the malfunction occurred.

PROCEDURE

CHECK HARNESS AND CONNECTOR (FUEL PRESSURE SENSOR - ECM)

Disconnect the fuel pressure sensor connector.
Disconnect the ECM connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance

Tester Connection	Condition	Specified Condition
B124-2 (PCR1) - B112-101 (PC)	Always	Below 1 Ω
B124-3 (VC1) - B112-54 (VCS)	Always	Below 1 Ω
B124-1 (E1) - B112-102 (E2S)	Always	Below 1 Ω
B124-2 (PCR1) or B112-101 (PC) - Body ground	Always	10 kΩ or higher
B124-3 (VC1) or B112-54 (VCS) - Body ground	Always	10 kΩ or higher
B124-1 (E1) or B112-102 (E2S) - Body ground	Always	10 kΩ or higher

Result

Proceed to
OK
NG

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

OK

CHECK HARNESS AND CONNECTOR (VC VOLTAGE)

A01QQIOC07

*a	Front view of wire harness connector (to Fuel Pressure Sensor)

Disconnect the fuel pressure sensor connector.
Turn the ignition switch to ON.

Measure the voltage according to the value(s) in the table below.

Standard Voltage

Tester Connection	Switch Condition	Specified Condition
B124-3 (VC1) - B124-1 (E1)	Ignition switch ON	4.5 to 5.5 V

Result

Proceed to
OK
NG

NG

REPLACE ECM Click here

OK

REPLACE FUEL PRESSURE SENSOR

Replace the fuel pressure sensor.

Result

Proceed to
NEXT

NEXT

CHECK WHETHER DTC OUTPUT RECURS (DTC P0191)

Connect the GTS to the DLC3.
Turn the ignition switch to ON and turn the GTS on.
Clear the DTCs.

Powertrain > Engine and ECT > Clear DTCs
Turn the ignition switch off and wait for 60 seconds or more [A].
Perform road test [B].
Repeat [A] and [B] for the number of trips detected.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

Powertrain > Engine and ECT > Trouble Codes

Read the DTCs.

Result

Result	Proceed to
No DTC output	A
DTC P0191	B

A

END

B

REPLACE ECM

Replace the ECM.

Result

Proceed to
NEXT

NEXT

GO TO STEP 7 Click here

REPAIR OR REPLACE HARNESS OR CONNECTOR

Repair or replace the harness or connector.

Result

Proceed to
NEXT

NEXT

CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

Connect the GTS to the DLC3.
Turn the ignition switch to ON and turn the GTS on.
Clear the DTCs.

Powertrain > Engine and ECT > Clear DTCs
Turn the ignition switch off and wait for 60 seconds or more [A].
Perform road test [B].
Repeat [A] and [B] for the number of trips detected.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

Powertrain > Engine and ECT > Trouble Codes

Confirm that the DTC is not output again.

Result

Proceed to
NEXT

NEXT

END