p0191 p0192 p0193

[relentless addiction]

these codes have been on several truck over the past years just wanting to spread the info.... easy fixes...

Thanks,
Ben




Circuit/System Description
The fuel rail pressure (FRP) sensor has a 5-volt reference circuit, a signal circuit, and a low reference circuit. The engine control module (ECM) monitors the voltage on the FRP sensor circuits. When the fuel pressure is high, the signal voltage is high. When the fuel pressure is low, the signal voltage is low. The fuel pressure regulator has a solenoid supply voltage circuit and a solenoid control circuit. The ECM controls the fuel pressure regulator , which regulates high pressure fuel that goes to the fuel injector rails and the injectors.

Conditions for Running the DTC
P0191
•DTCs P0016, P062F, P0116, P0117, P0118, P0192, P0193, P0652 or P0653 are not set.
•The ignition is ON, with the engine OFF.
OR

•The ignition has been off less than 70 seconds.
•This diagnostic runs continuously within the above conditions.
P0192 and P0193
•The ignition is ON.
•DTCs P0652 or P0653 are not set.
•These diagnostics run continuously within the enabling conditions.
Conditions for Setting the DTC
P0191
•The actual FRP is below 0 MPa (0 psi), or above 0.77 MPa (112 psi), when the ignition is ON and the engine is OFF.
OR

•The actual FRP is below 0 MPa (0 psi), or above 0.77 MPa (112 psi) within 70 seconds of the ignition being turned OFF.
P0192

The ECM detects the signal circuit voltage that is less than 0.254 volt for more than 1 second.


P0193

The ECM detects that the signal circuit voltage is more than 4.75 volts for more than 1 second.


Action Taken When the DTC Sets
DTC P0191, P0192, and P0193 are type A DTCs.

Conditions for Clearing the MIL/DTC
DTC P0191, P0192, and P0193 are type A DTCs.

Reference Information
Schematic Reference
Engine Controls Schematics

Connector End View Reference
•Engine Control Module Connector End Views
•Engine Controls Connector End Views
Electrical Information Reference
•Circuit Testing
•Connector Repairs
•Testing for Intermittent Conditions and Poor Connections
•Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Circuit/System Verification
Important:

•You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
•If you cannot duplicate the condition, operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
 1. Verify that DTCs P0652 or P0653 are not set.
⇒ If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle.
 2. Observe the Actual Fuel Rail Pressure parameter with a scan tool. During engine cranking, the pressure should be at least 10 MPa. With the engine running at idle, the pressure should be close to the Desired Fuel Rail Pressure. As the engine speed increases, the Desired Fuel Rail Pressure and the Actual Fuel Rail Pressure should closely match each other.
 3. Engine running, observe the DTC information with a scan tool. DTCs P0191, P0192 or P0193 should not set.
 4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
Important: Fuel pressure control will be disable if DTC P0087, P0088, P0192, or P0193 are set. Codes must be cleared to enable the device control.

P0191
 1. Turn OFF the ignition.
 2. Disconnect the ECM connector and the fuel pressure regulator connector.
 3. Test the fuel pressure regulator solenoid supply voltage circuit for a short to voltage.
 4. Disconnect the FRP sensor.
 5. Test the FRP signal circuit, the 5-volt reference circuit, and the low reference circuit for high resistance.
⇒ If all circuits test normal, replace the FRP sensor.
P0192
 1. Turn ON the ignition, with the engine OFF.
 2. Disconnect the FRP connector and observe the Actual Fuel Pressure parameter with a scan tool.
⇒ If fuel pressure is 0 MPa (0 psi), test the FRP sensor signal circuit for a short to ground. If the circuits test normal, replace the control module.
⇒ If fuel pressure is 200 MPa (29,00 psi), replace the FRP sensor.
P0193
 1. Turn ON ignition, with the engine OFF.
 2. Disconnect the FRP sensor connector and probe the signal circuit with a test lamp connected to ground. The test lamp should not illuminate.
⇒ If the test lamp illuminates, test the signal circuit for a short to voltage. If the circuits test normal, replace the control module.
 3. Connect a DMM between the FRP 5-volt reference circuit and ground, and measure the voltage. The voltage should be 4.7–5.2 volts.
⇒ If the voltage is not within the specified range, test for an open in the 5-volt reference circuit. If the circuits test normal, replace the control module.
 4. Connect a fused jumper between the FRP signal circuit and the low reference circuit and observe the actual fuel rail pressure parameter with a scan tool.
⇒ If fuel pressure goes to 0 MPa , replace the FRP sensor.
⇒ If fuel pressure does not go to 0 MPa, test the signal circuit and the low reference circuit for an open. If the circuits test normal, replace the control module.