CEL, Codes 335 and 214, help please?

[arco777]

My Explorer is giving me KOEO code 335 and CM code 214... according to FFI.com:
335=PFE or DPFE sensor voltage out of self test range
214=Cylinder identification circuit failure

Can anyone help explain this?

Background story: 94 Explorer, 2dr 4WD, 145K mile daily driver. Stock. When I bought it I put two new cylinder heads in due to a crack in one (850 miles ago) I recently started seeing the CEL come on occasionally when the motor is up to temperature and I get on the throttle hard, like accelerating on the highway. When I slow down, or sometimes even if I don't, the light goes out. No driveability issues or noticeable change in motor performance. The only other hiccup on the car is that when I cold start it, sometimes it idles rather rough (fluctuates and some vibration, sounds like it is missing) for maybe 5-15 seconds. I generally let it warm up, blip the gas a little, and it clears out and runs great after that. My snowmachines do the same thing when there's a bit of water in the carb and force of habit makes me treat the car the same, easing into the throttle till it warms up and clears out. Please correct me if this a bad thing to do.

Friday after work the light came on seconds after I started the car (drive to work was fine). No other problems besides the light, took it home and poked around and couldn't find anything obvously wrong. I tore the whole dash apart and scoured the engine compartment looking for a "trapezoid shaped connector that can handle 16 pins" and ignored the obvious STI/STO connectors because they didn't fit the Chilton book's description. I gave up, drove to work yesterday morning, didn't see a CEL all day. Today I was running errands and one start it came on again and stayed on. So, I browsed these (awesome) forums and found fordfuelinjection.com. I identified the connector, read the codes (Chilton didn't list either of the codes I got) and here I am.

So! What do these codes mean, should I even bother with them considering the car runs just fine, and if so how do I go about fixing this?

And on a side note, this makes three times that book has failed me with missing or incorrect info. I seem to recall Haynes manuals being better. Recommendations?

Thanks!

-Rhen

EDIT: Could part of my problem be plugs? I changed them for expensive Bosch Platinums the day before I took the car in to have the heads swapped, and the mechanic put in new Autolites and kept my Bosch plugs. He says he gapped the new plugs and told me correct gap without missing a beat, so I assume that's correct, but could these plugs be causing trouble? Now that I think about it, I also changed the oil just before taking it in with Mobil 1 and he did an oil change too.

EDIT 2: What about this? http://www.niehoff.com/techtips/n_sen.html
Might explain the the code 335 but not 214.

 

[MrShorty]

SOP when resolving EEc-IV codes is to work on the KOEO code(s) first, so I'll start there.

KOEO 335: The Niehoff reference was interesting, but would only apply to KOER/CM EGR codes where it passes the KOEO test. A KOEO 335 is set with the engine off, and the movement of the EGR valve isn't applicable. KOEO codes are almost always electrical in nature -- in this cases it points to a fault in the DPFE sensor circuit. Either there's a fault in the wiring between the PCM and the DPFE, or the DPFE itself has failed. As frequently as the DPFE's fail on these, I'd check the wiring and, if it checks out, replace the DPFE.

CM214: Can be either hard fault or an intermittent fault. The first step in diagnosing this one is to clear CM and test drive to see if the code comes back immediately or not. If it comes back immediately, then you start inspecting the CID circuit (CID signal is generated by the CaMshaft Position CMP sensor) for faults.

 

[arco777]

Re:

Thanks! CEL was on at startup again today and went out on the drive to work, and I haven't seen it since. I'll check the DPFE on Wednesday according to the following link, reset the memory, and see what happens. http://free-auto-repair-advice.blogspot.com/2007/08/understanding-ford-dpfe-and-egr-system.html

MAF was sooty. Cleaned it and that made the ping/rattle on acceleration on the highway go away and the motor run smoother all around. So far this car is really easy to work on, and that makes me happy. However, on the way home from the test drive, the ABS came on. One more thing to figure out.

 

[arco777]

Re:

Well, after cleaning the MAF no problems whatsoever anymore. No CEL, no rattle, better power, all cool. Replaced my battery connectors with new ones and no more ABS light issues or voltage fluctuations. Cool!

Thanks all! Now all I have to worry about is the "rod knock" on the 94 Explorer I'm looking at buying tomorrow. Can't have too many Explorers

 

[stevedtat]

is there a way to clean the DPFE? I'm having this problem also, except I'm getting hesitation also. I noticed that the vacuum going to the EVR is good, but going from the EVR to the EGR is very low. also...what's the best way to clean a MAF sensor? I don't want to ruin the thin wire that makes it work

 

[arco777]

You can clean the MAF sensor element (the two thin wires) using an electronics cleaner like QD Lectra-Motive. Spray it on the wires directly. If that doesn't get the soot off, use a Q-tip and VERY gently scrub the soot off. The wires bend easily so a light touch is required.