Trouble Code P0405
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Trouble Code P0405
2002 F150 Supercrew 5.4L engine
I have a missing problem that is erratic, it occurs more when the truck is under a load. I pulled the trouble codes and got the code P0405. There is not much info out there about this code. So what do I do to diagnose EGR low voltage circuit a? Should I simply replace the egr valve? Some other sites mentioned something about the replacing the DPFE sensor. What should I do about this? I have already replaced the spark plugs trying to solve the missing problem. This was before the trouble code was set.
I have a missing problem that is erratic, it occurs more when the truck is under a load. I pulled the trouble codes and got the code P0405. There is not much info out there about this code. So what do I do to diagnose EGR low voltage circuit a? Should I simply replace the egr valve? Some other sites mentioned something about the replacing the DPFE sensor. What should I do about this? I have already replaced the spark plugs trying to solve the missing problem. This was before the trouble code was set.
Technical Article Contributor
Joined: Oct 2005
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From: MI
Sounds like the DPFE or the EGR is stuck open. Here's a better description of your code and whats going on -
http://www.fordscorpio.co.uk/egrmonitor.htm
Thing is , a bad DPFE won't effect the way the motor runs. Neither will a stuck shut EGR. BUT if the EGR is stuck open - that's a driveability concern as explained in the link I posted..
With it stuck open the engine constanly is sucking the air from the EGR tube and trying to reburn it. The PCM program just signals and commands your DPFE to supply enough air to open the EGR for a couple seconds every so often, when it's working right.
http://www.fordscorpio.co.uk/egrmonitor.htm
Thing is , a bad DPFE won't effect the way the motor runs. Neither will a stuck shut EGR. BUT if the EGR is stuck open - that's a driveability concern as explained in the link I posted..
With it stuck open the engine constanly is sucking the air from the EGR tube and trying to reburn it. The PCM program just signals and commands your DPFE to supply enough air to open the EGR for a couple seconds every so often, when it's working right.
Last edited by jbrew; Sep 17, 2007 at 04:08 PM.
Technical Article Contributor
Joined: Oct 2005
Posts: 25,641
Likes: 19
From: MI
If you read the link and paragraph after clicking "EGR" at the bottom of the page , you would have a better perspective and wouldn't have asked that question - that's why I posted it.
Not necessarily, you could have two problems. You could have a bad coil , that's common as well.
Not necessarily, you could have two problems. You could have a bad coil , that's common as well.
Technical Article Contributor
Joined: Oct 2005
Posts: 25,641
Likes: 19
From: MI
No prob, like I said you could have two problems tho. Most of the time when a coil gets weak , it doesn't trip a cell right away even if it's misfiring. Pull your tubes to the DPFE to make sure there's no foreign matter in there - 405 points to tube flow.
The best way to get a misfire code is to give it hell -FLOOR IT!! when it's running sh^ty - do it 3 or 4 times , what ever it takes until you get a blinking check engine light. The blinking light means "Misfire" detected and a code is stored directing you to the proper cylinder.
The best way to get a misfire code is to give it hell -FLOOR IT!! when it's running sh^ty - do it 3 or 4 times , what ever it takes until you get a blinking check engine light. The blinking light means "Misfire" detected and a code is stored directing you to the proper cylinder.