Dodge Ram Truck 1500-2500-3500. Manual — part 1050

P0191-FUEL RAIL PRESSURE SENSOR PERFORMANCE (CONTINUED)

For the Engine circuit diagram (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CON-
TROL MODULE - SCHEMATIC - ELECTRICAL)

For a complete wiring diagram Refer to Section 8W.

•

When Monitored:
At key on.

•

Set Condition:
The fuel pressure sensor reading at key on does not match the expected fuel pressure reading at key on.

Possible Causes

OTHER DTC’S PRESENT

FUEL RAIL PRESSURE SENSOR

FUEL SYSTEM TAMPERING

INTERMITTENT CONDITION

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)

Diagnostic Test

1.

OTHER DTC’S PRESENT

With the scan tool, read DTCs.

Are any DTC’s present?

Yes

>> Repair other DTC’s first.

Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)

No

>> Go To 2

2.

FUEL PRESSURE READING

Using the scan tool, monitor the actual fuel pressure reading while the key is on and engine is not running.

Is the actual fuel pressure reading greater than 870 psi?

Yes

>> Go To 3

No

>> Refer to the INTERMITTENT CONDITION Symptom (Diagnostic Procedure). (Refer to 9 - ENGINE -

DIAGNOSIS AND TESTING)

Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)

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ENGINE - ELECTRICAL DIAGNOSTICS - DIESEL

DR/DH

P0191-FUEL RAIL PRESSURE SENSOR PERFORMANCE (CONTINUED)

3.

FUEL RAIL PRESSURE SENSOR

Visually inspect the fuel system components for signs of tampering, pay particular attention to the fuel pressure
sensor on the fuel rail and the fuel pressure sensor wiring harness.

Were any signs of tampering discovered?

No

>> Replace the Fuel rail pressure sensor.

Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)

Yes

>> Restore Fuel system to original condition.

Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)

DR/DH

ENGINE - ELECTRICAL DIAGNOSTICS - DIESEL

9 - 1123

P0192-FUEL PRESSURE SENSOR VOLTAGE TOO LOW

9 - 1124

ENGINE - ELECTRICAL DIAGNOSTICS - DIESEL

DR/DH

P0192-FUEL PRESSURE SENSOR VOLTAGE TOO LOW (CONTINUED)

For the Engine circuit diagram (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CON-
TROL MODULE - SCHEMATIC - ELECTRICAL)

For a complete wiring diagram Refer to Section 8W.

•

When Monitored:
With the ignition on and battery voltage greater than 10.4 volts.

•

Set Condition:
The circuit voltage to the ECM falls below a calibrated threshold for a certain period of time.

Possible Causes

OTHER DTC’S

FUEL PRESSURE SENSOR

(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO (G910) RETURN CIRCUIT

(K181) SIGNAL CIRCUIT SHORTED TO (G910) RETURN CIRCUIT

(K181) SIGNAL CIRCUIT OPEN

(F855) 5-VOLT SUPPLY CIRCUIT OPEN

(K181) SIGNAL CIRCUIT SHORTED TO GROUND

(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND

ECM

INTERMITTENT CONDITION

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)

Diagnostic Test

1.

OTHER DTC’S

Ignition on, engine not running.

With the scan tool, read DTCs.

Do you have multiple DTC’s?

Yes

>> Repair other DTC’s first.

Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)

No

>> Go To 2

DR/DH

ENGINE - ELECTRICAL DIAGNOSTICS - DIESEL

9 - 1125