Gurus! I need some diagnostic help...


My SES light was coming on so I got to use my scanner The code I got the first time was P0401. I erased the codes to see if I got it again and a few weeks later I got it along with P0401. The Codes mean EGR valve Overflow condition and underflow condition, respectively. I am now gettig the P0401 consistenly after about 15minutes of HWY driving. So I feel good about actually trying to fix the problem now as the error condition seems to be easily reproducable.

So, I hit up the Ford CD and the Chiltons and start testing the EGR system.

First, I took the Vacume line off the top of the EGR valve and then started the engine. Next, I pulled a vacume on the EGR valve. The engine subsequently stalled. (That sound like a good little EGR valve to me)

Second, I pulled the vac lines off one-by-one and traced the vacume. Looks like I am getting good flow through all lines. (Good)

Third, I pulled the connector off the EGR Valve Solenoid and put a multimeter on the harness with the key on run. measured 12.9V which means that the solenoid is getting good signal. (Good)

Fourth, I hooked a 12V source to the Solenoid and tried to blow into the vac sender line (The line that actuates the EGR valve) I then disconnected the 12V source and tried to blow again. Both times I got no flow. (I think this is bad, but maybe I am not doing this test right) Man, I still have a nasty taste in my mouth

Next, I went and bought a handheld vacum puller. My plan is to use this to test the sensor by pulling a vacume on it when its powered and then, measuring the output.

So, I am down to it being either the solenoid, the DPSF (EGR valve sensor) or both.

Am I missing something? Is this the right plan of attack? The sensor is ~$90 at the local dealer and I have not yet gotten a price on the solenoid but I am sure its around the 50-100 range. None of the aftermarket places around me carry these parts so I would have to go to the dealer or order online. One way will be a lot of time and the other a lot of money. So I wanted to do what I can to diagnose and get it right the first time.


Thanks in advance!

BTW: This is my F250SD 5.4L AOD with ~80k miles.


99 F250SD EC 5.4L 3.73 285 BFG/ATs...
99 Expy EB 5.4L

 

Well it turns out that whatever I did while diagnosing the problem fixed it. I guess I musthave had some carbon buildup or a birdnest in there and blowing out the vac lines and reattching them helped... Hmmm wierd, but good never the less.

99 F250SD EC 5.4L 3.73 285 BFG/ATs...
99 Expy EB 5.4L

 

Great diags!
Don't feel put off by not getting much help with your issue. A majority of these trucks don't have the EGR system, so problems/diags are pretty rare.

 

>A majority of these trucks don't have the EGR system, so problems/diags are pretty rare.

I concur. I do not have an EGR system. But did like your process of diagnostics very much!

 

CharlesValentine,

Where did you find a manual on the SD? I've been on Haynes Publication for a couple months now and all they say is "available soon". Is CHiltons out and available to the public and what about the Ford CD.. whats the story on that and where can I get one (Providing its not prohibitively expensive)

Thanks

 

>CharlesValentine,
>
>Where did you find a manual on the SD? I've been on Haynes
>Publication for a couple months now and all they say is
>"available soon". Is CHiltons out and available to the
>public and what about the Ford CD.. whats the story on that
>and where can I get one (Providing its not prohibitively
>expensive)
>
>Thanks

Slammer, I was able to find a cd-rom on e-bay for about 10.00. I'm quite sure that it's a pirate but it does work and has usefule info on it. Hope this helps. I still want a hands on paperback service manual on my trk but haven't seen one yet.

 

Well I just decided that I would start with the EGR sensor, and that did it! ended up costing me about $60 bucks. The new sensor is slightly different as it is plastic and the old was metal.
The old one had whit deposits all over the vacuum connection. FYI, there is an emmissions code on the driver door that is *very* important when getting replacement emissions parts for these trucks. I got the wrong part at first, special thanks to an alert parts guy at my local dealership for catching that one.

99 F250SD EC 5.4L 3.73 285 BFG/ATs...
99 Expy EB 5.4L

 

Thanks for the diagonistic discussion. What scanner did you employ? I'd like to buy one for future use on my '99 SD and the Crown Vic.

 

I got an actron cp9135 from autozone for about $150. WELL WORTH THE MONEY! WOHOO...

In fact I was totally excited when I got the SES light cuz I would get to use my new scanner.

Its easy to use and not fancy. There is a big button that says READ and one that says ERASE. Total no brainer operation. It even displays common code definitions so you don't have to go look up the code.

You can see the one I got here:

http://www.actron.com/cgi-bin/web_store.cgi?page=cp9135.htm&cart_id=


99 F250SD EC 5.4L 3.73 285 BFG/ATs...
99 Expy EB 5.4L

 

Thanks for Scanner info. Without pushing the truck too hard and being in low mileage, using a scanner probably won't bee necessary for awhile. However, I like to plan ahead. Some nice people at this site, eh?