2011 Ranger dpfe code

[shadow57x]

Hey everyone I just bought my 2011 Ford ranger with the 4.0 a few months ago knowing it had a po401 code thinking it was going to be a easy fix but, I was very wrong. It came with a new, egr valve the tube for the EGR on it so I figured it had to be the dpfe sensor. So I put the new one on and also replaced the solenoid and after driving it for about 500 miles the codes still there. I cleared it, then drove it another 300 miles and the code is still coming up. I replaced all of the vacuum lines and tested the dpfe sensor and selolnoid and everything is working how it should but, still the code won't go away. Could the EGR tube be faulty even tho when I test it the truck wants to stall? How much pressure sould be going to the dpfe sensor? I have very light vacuum at idle and light positive pressure at 3000 rpm. Any help will greatly be appreciated. Thanks

 

[RonD]

Welcome to TRS

DPFE measures Exhaust pressure on its 2 hoses
One hose and fittings is larger and one smaller, it matters

They are hooked up to the EGR pipe, one is closer to the EGR valve than the other
So when the EGR valve is opened by the computer and EGR modulator(solenoid), there will be a Pressure difference between the 2 hoses
The more the EGR Valve is opened the bigger the difference

Computer has these basic/generic codes it can chose from
P0400 Exhaust Gas Recirculation Flow Malfunction
P0401 Exhaust Gas Recirculation Flow Insufficient Detected
P0402 Exhaust Gas Recirculation Flow Excessive Detected
P0403 Exhaust Gas Recirculation Circuit Malfunction
P0404 Exhaust Gas Recirculation Circuit Range/Performance

It picked P0401..........Flow Insufficient
This means when the EGR is used, only after warm up and when engine is under a load(driving), the pressure difference is not going high enough

Clear the code and unplug the DPFE sensor's wires
Start and drive
Should get P0403 or P0404 "circuit" problem code pretty quickly
Sanity test for computer, shouldn't get P0401, if you do then its a computer issue

Make sure the hoses are correct, larger and smaller

 

[shadow57x]

Welcome to TRS

DPFE measures Exhaust pressure on its 2 hoses
One hose and fittings is larger and one smaller, it matters

They are hooked up to the EGR pipe, one is closer to the EGR valve than the other
So when the EGR valve is opened by the computer and EGR modulator(solenoid), there will be a Pressure difference between the 2 hoses
The more the EGR Valve is opened the bigger the difference

Computer has these basic/generic codes it can chose from
P0400 Exhaust Gas Recirculation Flow Malfunction
P0401 Exhaust Gas Recirculation Flow Insufficient Detected
P0402 Exhaust Gas Recirculation Flow Excessive Detected
P0403 Exhaust Gas Recirculation Circuit Malfunction
P0404 Exhaust Gas Recirculation Circuit Range/Performance

It picked P0401..........Flow Insufficient
This means when the EGR is used, only after warm up and when engine is under a load(driving), the pressure difference is not going high enough

Clear the code and unplug the DPFE sensor's wires
Start and drive
Should get P0403 or P0404 "circuit" problem code pretty quickly
Sanity test for computer, shouldn't get P0401, if you do then its a computer issue

Make sure the hoses are correct, larger and smaller

Ok thanks. That helps out a lot. If it's a computer issue then do I have to go get a new one?

 

[RonD]

Computer is LAST on the list, but yes, it would be replaced, but that is a very big PITA on 2004 and up Rangers because of the digital network

Since most of the parts are new, which means UNTESTED, not "working", you still need to do a few tests

Like EGR valve, get a few feet a vacuum hose that fits EGR port
Put one end on EGR valve and start engine
Suck on the other end, or use vacuum pump
Engine should start to run rough, keep sucking, see if it will stall, if so EGR can open far enough

Good PDF here that explains Ford EGR systems: http://tomco-inc.com/Tech_Tips/ttt35.pdf
Even shows the larger and smaller hoses, make sure they are correct

Computer also has these Ford specific codes
FYI, P0xxx are generic OBD2, same on Ford, GM, Audi, VW, Honda, ect......
P1xxx are maker specific, in this case these are Ford only definitions

P1400 Diff Pressure Feedback EGR Circuit Low Input
P1401 Diff Pressure Feedback EGR Circuit High Input
P1402 Exhaust Gas Recirculation Metering Orifice Restricted
P1403 Diff Pressure Feedback Sensor Hoses Reversed

P1405 Diff Pressure Feedback Sensor Upstream Hose Off/Plugged
P1406 Diff Pressure Feedback Sensor Downstream Hose Off/Plugged
P1407 Exhaust Gas Recirculation No Flow Detected
P1408 Exhaust Gas Recirculation Flow Out Of Self Test Range
P1409 EGR Vacuum Regulator Solenoid Circuit

You can use these for Sanity checks, like reversing the hoses, or unplugging one

You can check the EGR modulator(solenoid) with 9v battery, should "click" when 9v is applied, also blow thru it and make sure valve is opening

 

[shadow57x]

Computer is LAST on the list, but yes, it would be replaced, but that is a very big PITA on 2004 and up Rangers because of the digital network

Since most of the parts are new, which means UNTESTED, not "working", you still need to do a few tests

Like EGR valve, get a few feet a vacuum hose that fits EGR port
Put one end on EGR valve and start engine
Suck on the other end, or use vacuum pump
Engine should start to run rough, keep sucking, see if it will stall, if so EGR can open far enough

Good PDF here that explains Ford EGR systems: http://tomco-inc.com/Tech_Tips/ttt35.pdf
Even shows the larger and smaller hoses, make sure they are correct

Computer also has these Ford specific codes
FYI, P0xxx are generic OBD2, same on Ford, GM, Audi, VW, Honda, ect......
P1xxx are maker specific, in this case these are Ford only definitions

P1400 Diff Pressure Feedback EGR Circuit Low Input
P1401 Diff Pressure Feedback EGR Circuit High Input
P1402 Exhaust Gas Recirculation Metering Orifice Restricted
P1403 Diff Pressure Feedback Sensor Hoses Reversed

P1405 Diff Pressure Feedback Sensor Upstream Hose Off/Plugged
P1406 Diff Pressure Feedback Sensor Downstream Hose Off/Plugged
P1407 Exhaust Gas Recirculation No Flow Detected
P1408 Exhaust Gas Recirculation Flow Out Of Self Test Range
P1409 EGR Vacuum Regulator Solenoid Circuit

You can use these for Sanity checks, like reversing the hoses, or unplugging one

You can check the EGR modulator(solenoid) with 9v battery, should "click" when 9v is applied, also blow thru it and make sure valve is opening

Thanks. Now if everything works ok and I no longer have any codes is there some sort of driving procedure I can do to get all of the monitors ready?

 

[pjtoledo]

thanks Ron, I did not know there is an orifice in the EGR tube.

 

[RonD]

To clear P1000, follow the procedures here: https://www.totalcardiagnostics.com/support/Knowledgebase/Article/View/41/7/ford-motor-obd-ii-driving-cycle

One "drive-cycle" is when the engine is started cold, under 110degF, and then warmed up, above 170degF, then cooled down again

But in general driving, P1000, should clear itself in 2 to 3 days on its own, so 2 or 3 "drive-cycles"



There are two orifices on EGR tube, a larger one and a smaller one, besides the one at each end

 

[shadow57x]

This is how I have my dpfe sensor installed.

 

[RonD]

Looks like a new connector was installed, double check the splices to the original wiring

2008 4.0l SOHC is the latest wiring diagram I have
DPFE's 3 wires in the lower part

 

[shadow57x]

Looks like a new connector was installed, double check the splices to the original wiring

2008 4.0l SOHC is the latest wiring diagram I have
DPFE's 3 wires in the lower part

I went by the stock plug. I soldered and heat srunk the wires. I did go out and double checked the voltage. On the dpfe, Bottom wire 5v, middle is ground top wire is 1 volt at idle and a little over 4 volts when EGR opens. Is that about where I need to be?

 

[shadow57x]

Update: I unplugged the dpfe sensor and drove it and a po406 code came up. Then I put another new sensor on and cleared the code then drove it and got the po401 code again. So I decided to disconnect the EGR to see if I heard a big exhaust leak but I didn't. I put my finger over the end of the tube and at idle there's a little vacuum.

 

[RonD]

Should be no vacuum on EGR valve's vacuum line at idle, unless its very very little but that would cause other running issues

 

[shadow57x]

Ok thanks. I took off the EGR tube and the inside of it looked like it's brand new. I checked for a blockage in the exhaust manifold and it seemed to be clear. Unless I burned something out of there when I heated it with the torch. Now I'm thinking maybe the EGR isn't opening because of the vacuum selolnoid.what triggers that to switch on? Again thank you for taking the time to walk me through this.

 

[RonD]

The computer controls the EGR vacuum valve(solenoid)
It should have 12volts on 1 wire with key on
The other wire runs to the computer, its the ground wire for the solenoid

When the computer wants to add exhaust to intake air during driving, it will Pulse the ground wire(PWM) so solenoid opens a bit and passes limited vacuum to the EGR Valve
It then watches the Feedback from the DPFE sensor to see pressure difference so it can calculate how much exhaust is being added to the intake air
Computer can then increase Pulses for more vacuum or decrease Pulses for less vacuum, applied to EGR Valve

Computer uses similar PWM(pulse width modulation) on the ground wires for IAC Valve for idle, and EVAP valves, its a very accurate method to control DC voltage

 

[shadow57x]

Ok. Took it out today so far so good no codes. I just have to wait for the monitors to be ready.