KOEO Code 327 from Hell!!!

[mikeinri]

Hi guys,

Here's a follow up to my previous post regarding EGR codes.

I went to the Ford dealer yesterday, purchased a new EGR solenoid. Pulled the old one, resistance was 32 Ohms. New one was 31 Ohms. Both are within spec, but since the part isn't returnable, I put the new one in.

I also checked the voltage on the harness, 11.88 volts with the key on.

Still getting KOEO code 327. CM is also just 327.

The Ford dealer suggested that since my DPFE replacement sensor was aftermarket, that might be the source of the issue. I told him that after I replaced it, I had no codes for 6 weeks. He wasn't impressed.

He also said that the DPFE that was in my truck is the old metal style, and the replacement will be plastic, and I will have to splice in a new connector. That sounds fishy to me, I wonder if the computer could handle that? The new DPFE sensor is $160. My aftermarket one was $80-90 (I think, that was at the beginning of the year).

I also re-replaced the DPFE hoses (I had used regular fuel/emissions hose, I now have the correct silicone hose). The dealer thought the rubber lines might not be able to handle the heat.

So, where to go from here? It seems obvious that the problem is electrical (KOEO and all). I really hate part-swapping, but the only two parts that are left are the DPFE and the computer, correct???


Here's more background of this issue:

I recently had some EGR issues (94 4.0L). I've had codes 332, 336, and 337 (all KOEO). Those went away when I replaced the DPFE and the tubes connected to it.

Now I have a KOEO 327, which is a low voltage indication for the EGR circuit. I'm thinking it's the EGR vaccuum solenoid, but before I start spending more money on parts, I want to rule out a vacuum issue.


By the way, I think I found a good Ford dealer. He tried really hard to make me not buy anything but to have them do the diagnostics first, so I don't waste time and money chasing this down. I have so much time working through this (in the truck and on the forums), I really thought I was getting close. After wasting a good hour this morning, I'm starting to think that he was right...

I'm open to any ideas...

Mike

 

[mikeinri]

Did a quick voltmeter test on the DPFE (backprobed the harness).

With engine running (cold):
Power wire to ground gives about 5 volts (which is correct).
Signal wire to ground gives 0.03 volts (which is way low).

With engine running (warm):
Power wire to ground gives about 5 volts (which is correct).
Signal wire to ground still gives 0.03 volts (which is way, way low).

So, I bought the Ford DPFE, I'll let you know how it goes.

The part about this that I find odd is that the CEL does not come on immediately when the engine is started. It comes on after about a minute or so of the engine running. With the signal voltage that low when cold, shouldn't I expect the CEL to come on immediately, or does the computer wait for input from somewhere else before making an evaluation of the DPFE signal strength?

As always, any and all other ideas are appreciated.

Mike

 

[mikeinri]

OK, one more update.

New Ford DPFE is in. Had to cut out the old harness and splice in a new one. It doesn't look like you can backprobe the new harness, hope that won't be an issue down the road...

Anyway, the dreaded KOEO 327 is gone. I cleared the CM, and took a 10-mile drive, no CEL.

Hopefully, this is the end of it. I'm not thrilled that I wasted $80 on an aftermarket DPFE that only lasted 6 weeks. Hopefully, that isn't a sign that there's something else going on with my truck that will foul the new $160 Ford DPFE.

Mike

 

[mrboyle]

To answer your question about why it takes time to set the code is that the computer typically won't set emissions related codes until it enters closed loop (after it warms up).

 

[Dre]

and I assume that dreaded DPFE code has not come back to haunt you again? Let me know, I've got the same issue.

 

[mikeinri]

It's gone, and has stayed away!

 

[94xlt4WD]

It's gone, and has stayed away!

Hi mikeinri,
i got a DPFE issue (code327) , changed DPFE with the new one, even changed my TPS, still the same problem!?
maybe you can check out my thread
http://www.explorerforum.com/forums/showthread.php?t=236184
Thanks