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Steve, Ford Technician
Category: Ford
Satisfied Customers: 6915
Experience:  30 years working for Ford dealer. Ford Master tech.
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Ford I have a 2004 F350 6.0 superduty. I got the P0401 trouble

Customer Question

I have a 2004 F350 6.0 superduty. I got the P0401 trouble code egr recirulation flow, I pulled the valve cleaned it put it back in 25 miles later same code. I replaced it with a new one 25 miles later same code. WHATS GOING ON.
Submitted: 6 years ago.
Category: Ford
Expert:  Steve replied 6 years ago.

Steve :

Hello and Welcome to Justanswer, My name is XXXXX XXXXX I am here to try and assist your with your question

Steve :
Circuit Function

The exhaust gas recirculation (EGR) actuator is a variable position valve that controls the amount of exhaust that enters the intake manifold. The EGR is controlled by the PCM using a pulse width modulated signal that varies from 0-100%. The EGR actuator consists of two components, a valve with actuator (solenoid) and a position sensor to monitor valve movement. The EGR sensor is a potentiometer sensor. When the EGR receives a 5-volt reference signal and a ground from the PCM, a linear analog voltage signal from the sensor will indicate position of the EGR valve.

Fault Detection

The PCM will detect an open or short in the EGR control circuit after the KOEO test has run and set a DTC. The EGR actuator can be tested for a stuck or sticking valve by performing an output state low test while monitoring EGRP percentage.

NOTICE: The PCM harness connectors must be properly seated and the connector latch properly attached to eliminate possible driveability concerns or a no-start condition. Installing PCM connectors on an angle may cause an improper connection, misdiagnosis, and damaged components. Install the connector until the lever pivots and seats itself. Apply light pressure to get the connector into position on the PCM and then fully seat the connector.

Note: Visually inspect the harness connectors for corrosion, damage, proper mating and correct pin tension.

Note: When the PCM is disconnected additional DTCs will be set. Clear all DTCs after restoring the vehicle.


DTC Descriptions

  • P0401 = EGR Flow Insufficient Detected

  • P0402 = EGR Flow Excessive Detected

  • P0403 = EGR Control Circuits

  • P0404 = EGR Control Circuit Range/Performance

  • P0405 = EGR Sensor A Circuit Low

  • P0406 = EGR Sensor A Circuit High

  • P1335 = EGR Position Sensor Minimum Stop Performance

  • P1408 = EGR Flow Out Of Self-Test Range


Steve :

the egr valve is not opening and if you replaced the egr valve you have a wiring or computer problem

Steve :

    Note: Note: Visually inspect the vehicle for aftermarket accessories and performance modifications (air filter, exhaust system, intake system, performance chip, turbocharger, etc.). Refer to Section 1 Diesel Electronic Engine Control (EC) System Modifications to OBD Vehicles.

    Note: Refer to the PCM and component connector at the beginning of this pinpoint test.

  • Possible causes:

    • restricted air flow (intake or exhaust)

    • charge air cooler (CAC) system leaks (hoses/cooler)

    • EGR valve stuck

    • EGR valve O-rings

    • restricted EGR cooler

    • EGR valve position sensor bias

    • MAP sensor

    • Water or dust contamination on MAF sensor element (F-Super Duty/Excursion Early Build Only)

    • EP sensor bias (E-Series or F-Super Duty/Excursion Late Build Only)

  • Perform On-Demand Self Test.

Steve :

  • Engine at normal operating temperature.

  • Key ON, engine OFF.

  • Access the PCM and the EGR System Test.

  • Carry out the EGR System Test while following the directions on the scan tool.

Did the EGR System Test pass all tests?

Yes No
For DTCs P0401 or P0402, GO to Pinpoint Test KA .

For all others, unable to duplicate the condition. CHECK for a loose connection, and damaged or corroded terminals. WIGGLE the harness attempting to recreate the concern. REPAIR as necessary. REFER to Section 3, No DTCs Present Symptom Chart, if a driveability concern exists.
If the EBP and MAP PIDS are both out of range, GO to Pinpoint Test KA .

For all other non EGR PIDS that are out of range, REFER to the appropriate pinpoint test to continue diagnosis.

For EGR actuators outside the limit of the EGRVP response test, INSTALL a new EGR actuator. CLEAR the DTCs. REPEAT the self-test.

Steve :

need to preform a egr test with a 2500 dollar scan tool and a laptop additional cost to diag the concern.

Steve :

if you replaced the egr valve you covered the basics then you have a deeper concern that requires sophisticated expensive equipment.


while driveing the truck to check it out it started surging at times it ran ok then it would surg hard blow black smoke and buck then run fine for awile

Steve and 4 other Ford Specialists are ready to help you
Expert:  Steve replied 6 years ago.
need to take it to the dealer for diag it will be cheaper in the long run. and then you could replace the parts.

this problem will be to difficult to diag over the internet and with no test equipment .