Check Engine Code P0401 - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars
Ford Forum Ford Forum

» Auto Insurance
» Featured Product
» Wheel & Tire Center

Go Back   Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars > Ford Cars and PAG Vehicles > Ford Crown Victoria | Mercury Marauder | Grand Marquis | P71
Register Home Forum Active Topics Photo Gallery Auto Loans Garage Mark Forums Read Auto Escrow

Ford Crown Victoria | Mercury Marauder | Grand Marquis | P71 Forum for discussion of the Ford Crown Victoria, Mercury Marauder, Mercury Grand Marquis and P71.

FordForums.com is the premier Ford Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools Display Modes
Old 03-26-2010, 23:47   #1 (permalink)
01 CROWN VIC
 
Join Date: Oct 2007
Location: Texas
Posts: 75
Check Engine Code P0401

01' CV base model has 110K and the above check engine light error code. A/zone identifies it as either an EGR valve (orig still on vehicle), EGR position sensor (replaced in 08') or an EGR solenoid (original). I bought a Borg-Warner valve this a.m., what are the chances it's the valve and not the sensor (or solenoid??)? My place wants $90 to narrow it down, hell I can replace most of the parts for that!!

On a seperate note, when I attach the gasket to the EGR valve do I permatex it to the 1. valve 2. the block 3. both 4. not at all don't need it?
I plan on using the non-hardening permatex gasket sealer...but never really knew which side(s) to seal?? Thanks in advance!
prometheis is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 03-27-2010, 04:00   #2 (permalink)
Registered User
 
KStromberg's Avatar
 
Join Date: Feb 2010
Location: Minnesota
Posts: 281
Garage
Re: Check Engine Code P0401

Quote:
Originally Posted by prometheis View Post
01' CV base model has 110K and the above check engine light error code. A/zone identifies it as either an EGR valve (orig still on vehicle), EGR position sensor (replaced in 08') or an EGR solenoid (original). I bought a Borg-Warner valve this a.m., what are the chances it's the valve and not the sensor (or solenoid??)? My place wants $90 to narrow it down, hell I can replace most of the parts for that!!

On a seperate note, when I attach the gasket to the EGR valve do I permatex it to the 1. valve 2. the block 3. both 4. not at all don't need it?
I plan on using the non-hardening permatex gasket sealer...but never really knew which side(s) to seal?? Thanks in advance!

Welcome to the wonderful world of diagnostic troubleshooting. You are going to need to do some troubleshooting here, although I may be a bit late on posting because apparently you have already bought the valve.

First off, please realize that while you may be getting this code, it does NOT necessarily mean that you are not getting EGR flow due to a faulty valve but rather the PCM is not detecting any. This may point to a bad DPFE(Delta/Differential Pressure Feedback Exhaust) sensor which is quite common and the most probable cause and usually fails a lot more than the EGR valve does.

The EGR valve itself may need to simply be cleaned out. They commonly build up with carbon.

Do this:

Check to see if the EGR valve opens using a vacuum pump, with the engine running pull a vacuum on the EGR valve, the engine will stumble or die if the valve opens. Also check to see if the EGR valve holds vacuum. Check the EGR tube assembly for cracks and blockages.

Next check the DPFE sensor pressure pipes for splits and blockages and check the EGR tube assembly for cracks and blockages.

You will need to back probe the DPFE connector (or use a breakout box or scan tool) with the Key On Engine Off (KOEO) and check for output voltages while pulling a vacuum on the pressure pipes.

You may find it easier to check everything else and by a process of elimination condemn the DPFE sensor as a "best guess"

The one thing I do NOT know is exactly what those voltage readings should be, but if it makes you feel better, I am really leaning towards that DPFE sensor as being the culprit especially if you pull vacuum on the EGR valve and it responds properly.

Good Luck!
__________________
-1992 Ford F-150 (winter truck)
-1998 Lincoln Mark VIII LSC (fun car)13.591@101.72mph
KStromberg is offline   Reply With Quote
Old 03-27-2010, 08:56   #3 (permalink)
2002 F150 XLT
 
Bert's Avatar
 
Join Date: Nov 2008
Location: Oregon
Posts: 9,847
Re: Check Engine Code P0401

That's my opinion too. The new plastic low profile sensor is the 0.9 to 1.1 V version with some of the older versions being the new 0.9 to 1.1 V version. If the signal voltage is wrong check the 5 V reference and ground before replacing the sensor
__________________
Bert
Bert is offline   Reply With Quote
Old 04-10-2010, 02:59   #4 (permalink)
01 CROWN VIC
 
Join Date: Oct 2007
Location: Texas
Posts: 75
All's well!

Just an update and thanks for the inputs! I installed the new EGR valve and reset the check engine light. The light stayed off! (for exactly 2 days and then came back on)! The car seemed to have a little more get up and go after R&R'ing the EGR valve, is that possible? BTW the gasket sealer goes between the gasket and the block.

Sooo not being electrical in any way, I went and bought a Borg-Warner EGR pressure feedback sensor ($38) and had P/Boys install it. After 5 days all remains well! It just seemed strange that the sensor was replaced in 6/08 and needed replacing again 22 mos later?????

The car now has over 111K and I also flushed the radiator and charged the A/C for summer. I'll change the oil at 112,500 mi and then hit the road and hey, only 18 more payments...
prometheis is offline   Reply With Quote
Old 04-10-2010, 13:03   #5 (permalink)
2002 F150 XLT
 
Bert's Avatar
 
Join Date: Nov 2008
Location: Oregon
Posts: 9,847
Re: Check Engine Code P0401

It depends on the part manufacurer. Some aren't as good as others and sometimes good ones can have a flaw. Glad it's working. Thanks for the update.
__________________
Bert
Bert is offline   Reply With Quote
Sponsored Links
Advertisement
 
Reply

  Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars > Ford Cars and PAG Vehicles > Ford Crown Victoria | Mercury Marauder | Grand Marquis | P71



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Powered by vBadvanced CMPS v3.2.2

All times are GMT -7. The time now is 18:34.



Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO 3.6.0
Garage Plus vBulletin Plugins by Drive Thru Online, Inc.