Cowman5858

Hello all I am having an issue with the check engine light continuing to come on and its throwing a rail code for insufficient fuel. I had Dodge electric test the injectors and they were from 104 to 98 being the lowest. Is that ok they didn't really tell me but I was guessing 100 is optimal?? They told me they weren't convinced they needed to be changed yet but I put a new lift pump in it as it was running 20% below optimal that didn't take care of it after a few miles the light came back on. Im wondering if the problem could be as simple as the fuel pressure limiting valve it is dribbling fuel to the return line when it shouldn't be. Does anyone know could this be the issue?? Or should I just bite the bullet and put injectors in it??? Any insight would be much appreciated! Thanks

Brad

CTD NUT

Let's start with what code you are getting...tell us the code number(s).

Cowman5858

I will run it by the shop and get the code number. I don't remember it.

Cowman5858

Its the P0148 code I thought that was it but just double checked it.

CTD NUT

That is the checksum code for rail pressure. There could be several possible causes. Below is the FSM diagnostic procedure for this code:

P0148-HIGH PRESSURE COMMON RAIL (HPCR) CHECKSUM
For a complete wiring diagram Refer to Section 8W.

When Monitored:
While the engine is running.

Set Condition:
A deviation between the fuel pressure set point and the actual fuel pressure.

Possible Causes
OTHERS DTC'S PRESENT
FUEL LEAKS
FUEL CONTROL ACTUATOR
FUEL PRESSURE SENSOR
CASCADE OVERFLOW VALVE
CHECK VALVE DAMAGED OR BLOCKED
FUEL RETURN LINES OBSTRUCTION, DAMAGE, OR DEBRIS
LIFT PUMP FLOW
AIR IN FUEL SYSTEM
LEAKING FUEL INJECTORS OR HIGH PRESSURE CONNECTORS
PRESSURE LIMITING VALVE
HIGH PRESSURE FUEL PUMP
INTERMITTENT CONDITION


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

Diagnostic Test
1. OTHERS DTC'S PRESENT

--------------------------------------------------------------------------------
With the scan tool, read DTCs.

Are any other DTC's present?

Yes
Repair other DTC's first.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).

No
Go To2



2. FUEL LEAKS

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Ensure that the fuel level is above 15% using the scan tool.
Visually inspect the low and high pressure side of the fuel system for fuel leaks or damaged components.

Do you have any fuel leaks or damaged components?

Yes
Repair the fuel leak.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)

No
Go To3



3. FUEL CONTROL ACTUATOR

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Check for a mechanically stuck Fuel Control Actuator (FCA). Using the scan tool, actuate the fuel control actuator.

NOTE: The fuel control actuator will only click when cycled off..



Do you hear a click from the actuator when you cycle the actuator off with the scan tool?

Yes
Go To4

No
Replace the fuel Injector pump.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)



4. FUEL PRESSURE SENSOR

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Using the scan tool, monitor the fuel pressure reading from the fuel rail pressure sensor at idle and at 2000 RPM

Is the fuel rail pressure reading higher at 2000 RPM than at idle?

Yes
Go To5

No
Replace the fuel pressure sensor.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)



5. HIGH FUEL PRESSURE

--------------------------------------------------------------------------------
Using the scan tool compare the fuel rail pressure set point with the actual fuel rail pressure.

Is the actual fuel rail pressure higher than the fuel rail pressure set point?

Yes
Go To6

No
Go To9



6. CASCADE OVERFLOW VALVE

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Perform the no trouble code test "*fuel pump return flow test" .(Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

Did the fuel injection pump pass the test?

Yes
Go To7

No
Replace the Fuel pump.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)



7. CHECK VALVE DAMAGED OR BLOCKED

--------------------------------------------------------------------------------
Check the fuel drain line check valve in the rear of the cylinder head for signs of damage, blockage, or debris.

Is the check valve damaged or blocked?

Yes
Repair the cause of the damaged or blocked check valve or replace the valve.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)

No
Go To8



8. FUEL RETURN LINE OBSTRUCTION, DAMAGED OR DEBRIS

--------------------------------------------------------------------------------
Check the fuel return lines for signs of obstruction, damage, or debris.

Are the fuel drain lines damaged or blocked?

Yes
Repair cause of high fuel drain line restriction.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)

No
Go To9



9. LIFT PUMP FLOW

--------------------------------------------------------------------------------
Perform the no trouble code "*LIFT PUMP FLOW TEST". (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

Did the Lift pump pass the test?

Yes
Go To10

No
Replace the Lift Pump.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)



10. PRESSURE LIMITING VALVE

--------------------------------------------------------------------------------
Perform the no trouble code test "*PRESSURE LIMITING VALVE ON THE FUEL RAIL FOR INTERNAL LEAKS".

Did the pressure limiting valve pass the test procedure?

Yes
Go To11

No
Replace the Pressure Limiting Valve.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)



11. LEAKING FUEL INJECTORS OR HIGH PRESSURE CONNECTORS

--------------------------------------------------------------------------------
Perform the no trouble test "*INJECTOR RETURN FLOW TEST". (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

Are any Injectors leaking or high pressure connectors leaking?

Yes
Replace or repair the leaking fuel injectors or high pressure connectors.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)

No
Go To12



12. HIGH PRESSURE FUEL PUMP

--------------------------------------------------------------------------------
Perform the no trouble code test "*HIGH PRESSURE FUEL PUMP PERFORMANCE TEST". (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

Did the fuel pump pass the high pressure fuel pump performance test?

Yes
Refer to the INTERMITTENT CONDITION Symptom (Diagnostic Procedure). (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

No
Replace the High pressure fuel pump.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)

Cowman5858

Thank you! I found that check list yesterday too.