'97 5.0L code questions

[rizzjc]

I know codes are probably beat to death, but driving to work this morning my check engine light came up. Handy having the Scanguage right there, I pulled the codes, and it reports 3. 402, 0002, and 3000. I've found plenty of info on the 402 code, but can't find any reference to the other two. Should I just troubleshoot the 402 and see if everything clears after that?

I also have noticed over the past two tanks of gas, a noticeable drop in gas mileage, 1-2mpg, which is not typical for me. I've been watching it, thinking that maybe it is because my wife has driven it a few times ( Don't laugh, she kills my gas mileage), and I did pull the boat once, but it still seemed odd. Reading through some of the posts, I wonder if that is related to the code.

Anyway, appreciate any thoughts on the other two codes. Otherwise I'll just debug the 402 and see where I am after that.

 

[jp450]

I am guessing the codes you have gotten are P0402, P0002, and P3000. If so here is what they mean:

P0402 - Exhaust Gas Recirculation Flow Excessive Detected
possable cause is a bad EGR valve or DPFE sensor

P0002 - Fuel Volume Regulator Control Circuit Range/Performance
possable cause is a bad fuel pressure regulator.

P3000 - Not a valid code. Maybe P0300 - Random misfire.

I would recomend that you check the fuel pressure at the rail with a fuel pressure gague. I forget what the spec is but I think its about 50 PSI. (someone help me out here) If you have too much then you need to replace the regulator. The high fuel pressure may be the reason you are getting the P0402. And if it is P0300 that you are getting the fuel pressure regulator may be the cause for that too.

 

[rizzjc]

Thanks for the response. Out of town right now, so not sure when I'll be able to look at it. Cleared the codes, so I'll see if they pop up again. Then I'll probably need some help with how to check the fuel pressure, but I'll read up in my repair manual.

 

[performancenut]

JP gives good information. I would check the DPFE and possibly replace this item if never done before. Are your plug wires relatively new? Seems like the 5.0 likes to arc the spark discharge through bad connections, carbon build-up, etc. resulting in random misfires. Many times, the Fuel Pressure Regulator, if bad, will have some fuel in the vacuum line attached to it. Pull the line and see. A quick fuel pressure can be obtained at the schraeder valve on the fuel rail.

 

[rizzjc]

Yes, plugs and wires are fairly new. I'll probably go ahead and replace the DPFE when I get home, and see what that does. 135k on the original. That's what most other posts pointed to, but I couldn't find those other two codes, but I can see if they still show up after replacing the DPFE. Thanks.

 

[rizzjc]

Well, I was near the dealership one day, so I stopped to pick up the DPFE. I was surprised at how quickly she went and grabbed it without even blinking. I shoulda known better. So, I go and start digging around under the hood, and apparently I've got the old system, with no DPFE. I took some photos, and have my repair manual, so I'm gonna do some more digging so that I at least know what everything is, and can look at suspect lines, etc., but since I probably can't try to DPFE to see if it fixes the problem, I'm not sure where to go next. Any ideas?

There is still the idea about the fuel pressure rail, but I don't know how to do that, probably don't have the equipment, and would think that I'd be having some other noticeable problems with how the vehicle runs if that were it. Yes? No?

 

[410Fortune]

The 96 EGR system has no tube from the pass side exhaust manifold to the EGR valve

the 97.5 system (with P heads) has the EGR tube from the manifold to the EGR valve.

the 96 system is plumbed through the intake manifolds.
I think you are correct the 96 system has no DPFE sensor, it has the older style EGR, I replaced the sensor on my 96 truck, I had excessive flow and it was the valve itself. A fun job! the throttle body and elbow must come off in order to get at it if I remember right....the orange bladder in my EGR valve itself has a 1/2" long tear in it. It took my friend Chris at Carquest to find the correct part for me and get it in, Ford wanted like $120 or something and were skeptical they were looking at the right part. The part is the same as they used on the HO Mustang block I believe, it was like $50.

 

[rizzjc]

So, mine is an early '97 model; got in in August '96, one of the first '97's off the truck (I ordered it). So, what exaclty does "plumbed through the intake manifold" mean? So, which sensor did you replace if the '96 does not have the DPFE either? Would it be a good idea for me to just pull the EGR and take a look at that? I believe I've at least identified where it is, and from what I saw, it appears that I can get to it without removing anything else (as he later curses and kicks his vehicle trying to get it out ).

So, if the DPFE would typically throw the 402 code, and I don't have a DPFE, what might be the next thing to throw it? The EGR itself? I've got the two other codes (0002 and 3000), but I'm concentrating on the 402 for now to see if they all go away. JP450 said that 3000 is an invalid code, but that's what I get (not 0300), so maybe I'm best off ignoring that one anyway.

 

[410Fortune]

The egr on your 96 gets the gasses form the exhaust internally though the intake manifold

You will have to remove the throttle body and elbow to get at the entire EGR system, trust me. It will actually save you time.

To learn about the EGR, sensors, different types check out:
Fordfuelinjection.com

Your system consists of a EGR valve (big round unit bolted to the intake elbow) a vacuum switch that the computer uses to send manifold vacuum to the EGR diaphram (valve) and thats about it. the flow sensor came on later models, and it just send the computer feedback on how much is passing through the EGR system I believe.

I would first check out your code, it may be your computer will always throw this code becuase you have no DPFE sensor.
Now this is from memory, if I missed something sorry I would have to go look at my 96, I am used right now to working on my 97 5.0L which has the later style EGR.

EDIT:

OKay I found my old thread from when I replaced the EGR on my 96, seems I did get the part from Ford, not from Carquest and I foudn the high tempature EGR vacuum hose was also original and broken as well as the tear in the diaphram:

http://www.explorerforum.com/forums/showthread.php?t=127724&page=2&pp=20

Another 96 EGR thread:
http://www.explorerforum.com/forums/showthread.php?t=122760&highlight=96+XLT+EGR

 

[rizzjc]

Yeah, your description sounds about the closest to what I was looking at under my hood (with what little I know about it anyway), so thanks for that. Guess I'll be tearing into it one of these days and pulling out the EGR. I might try replacing all of the lines first, and see what happens. It is somewhat intermittent right now - it'll sometimes go 200 miles without throwing a code. Other times it is under 50 miles. I've got until August to mess with it.

So, just to clarify this, there is some sort of diaphram inside the EGR, and I should be able to inspect that when I remove it? I'm unclear where the code is being reported from, given that on later models the DPFE tells the computer there is a problem. Where does this system report the problem from? I guess I'll go read up on the EGR systems (again) and see if it makes more sense.

I'm learning slowly. I took back the $100 DPFE that Ford sold me. I knew she went and grabbed that thing off the shelf mighty quick!

 

[410Fortune]

http://fordfuelinjection.com/?p=11

http://fordfuelinjection.com/index.php?p=35

http://fordfuelinjection.com/index.php?p=43

 

[rizzjc]

Hmmm, OK, this is starting to look more like my system. So it looks like I might have the EVP instead of the DPFE, and that might be what I need. I'm just gonna steal my wife's garage bay so I can take it apart and bring the parts to the parts store, or Ford, I need to. Looks like I can test the EVP per the links you posted above too.

Thanks for the help.

 

[410Fortune]

I friggin love that site, the day somebody showed it to me was a great day...

You can get the part numbers directly off the parts you remove.

 

[jp450]

So, if the DPFE would typically throw the 402 code, and I don't have a DPFE, what might be the next thing to throw it? The EGR itself? I've got the two other codes (0002 and 3000), but I'm concentrating on the 402 for now to see if they all go away. JP450 said that 3000 is an invalid code, but that's what I get (not 0300), so maybe I'm best off ignoring that one anyway.

I was just thinking of somthing. What is the letter before the code? It should be a "B", "C", "P", or a "U". It is important to know that. I did some reasearch and the only code with 3000 for a Ford that I could find is U3000. Which would be "Right Rear Tire Pressure Sensor Is Not Responding" I don't think that there was the pressure sensors on a 97 Ex but I could be wrong.

What is the letter before the code?

Jeff

 

[rizzjc]

I just got 3 new codes to add to the original. All "P" codes, I believe:

0125
0800
0000

Not able to find 0000 or 0800. 125 appears to be TPS related. I hope hoping these might be related to, or help with, the original codes I have, but not sure. Anybody know what the 0800 is? I guess the 0000 is invalid.

 

[jp450]

I show P0125 as being Engine Coolant Temperature [ECT] Excessive Time To Closed Loop Fuel Control.

I thought P0000 was PCM not ready or somthing like that. I will have to look that one up in the other book.

P0800 come up invalid on my first search. I will look in the other book to see.

Jeff

 

[rizzjc]

Thanks. I did see one place about the ECT for P0125, but then somewhere else it said TPS, so who knows. You'd think it would not be that difficult for these code lists to be accurate. Even my factory repair manual doesn't show most of the codes that I have had.

 

[rizzjc]

Rrrrrrrrr!

OK, a week and a half in my garage, a new EGR sensor, a lot of cleaning of the various intakes pieces, and I might be able to say the truck is running smoother (it was running pretty good all along), but I can't say that my CEL didn't light up after about 20 miles of driving. Only thing I still need to do is replace the PCV now that I found it, but I gotta order that, and a new grommet, but I find it hard to believe it could have anything to do with my 3 codes (402, 0002, 3000). Not really sure where to go next.

Tested the EGR when I took it apart, and it appears to be fine. About 20 in Hg to fully open the EGR, and it held fine, so no leaks. Cleaned and checked everything. Cleaned EGR extension housing, throttle body, EGR tube (what I could get to), and the IAC and MAF.

Open to ideas. Please!

 

[rizzjc]

No more ideas for me?

 

[rizzjc]

Well, this is an old thread, but I still have this issue, so I thought I'd share some interesting data I collected while debugging. Trying to figure out a way to test the EGR itself by looking at the sensor output when the EGR is supposed to be closed, I pulled out the old EGR sensor that I had replaced, and hooked it up to the harness. With it NOT mounted to the EGR, it reads just over 0 volts (something like .03 volts). To read this I just stuck some pins in the wires coming out of the harness. Plugging the harness back into the NEW sensor, which IS mounted to the EGR, I get a reading of about .728 volts. According to the info I found at fordfuelinjection.com, the malfunction is when the sensor reads anything over .72 volts. I would think that there would be a "don't care" range between the closed and open state, but the spec for the P0401 (EGR *IS* closed, when it should be open) is anything under .78 volts.

It was suggested to be to just replace the EGR, since buildup and "pitting" could cause a slight reading, given the way the sensor works. Before spending the money on more parts, I wanted to confirm this, and although this data doesn't seam decisive to me, it tells me that the EGR is definitely pushing a little bit on the sensor, and given how close the reading is, I'd think that sometimes it could jump up enough to throw the code (not really knowing EXACTLY at what voltage the code will be generated).

OK, I'm probably just rambling to myself, but helps me to puts my thoughts together, and try to understand how this stuff works.