I scanned my Ranger with my new Scangauge II and came up with 3 trouble codes: P0401, U0100, and P0208.

P0401 - EGR Flow Insufficient
U0100 - Lost Communication with ECM/PCM "A"
P0208 - Injector Circuit Malfunction, Cylinder 8

I've scanned it 3 times now, and P0208 and P0401 always come up. I think this is the first time I've seen the U0100 code. What would be the first thing to look for to fix these trouble codes? What are the most common problems with these Rangers, and what parts should be replaced first?.

I don't have 8 cylinders! Why do I keep getting P0208??

 

P0401 - 95% of the time is a bad DPFE sensor (EGR position sensor). Very quick and easy to replace.. two bolts, a connector, and two small exhaust hoses.

U0100 - I wouldn't worry about this unless it continually comes back.. sometimes the modules have a "brain fart" and lose a packet of data or two, then this code gets stuck in memory for a long long time, only to freak out the first person to scan it.

P0208 - Injector #8? Yes there should be no reason to get this code, obviously. Before jumping to conclusions, run to a local chain parts store as most will scan your codes for free.. keep in mind they'll use a cheap, generic code scanner, but if they come up with something different, there may be a compatibility problem with your Scangauge II. Rare, but it does happen. Also see if there are any software updates available for your Scangauge.

Good luck.

 

I had a friend scan it for codes tonight (I didn't clear them the other day) and the same ones came up. Including the P0208. He's got one of those fancy, put-your-kid-through-college scan tools.

 

I would chase the P0401 first... like I said it's likely the DPFE sensor. Replace that and see if it fixes the first code.

I've heard of these things causing some strange symptoms when they go bad... although I don't see any correlation with the P0208... but really that's about the only advice I can give at this moment.

 

FWIW, I've heard of aftermarket chips causing "Lost Communication with ECM/PCM" type codes. Do you have a chip installed? Have you tinkered with the PCM harness connector lately?

You might try erasing the codes and then driving around for a while to see if those funky U0100 and P0208 DTCs come back. I suspect the P0401 will return.

 

I haven't done anything with the PCM yet. Once I get my engine modifications done I may work on it, but as of right now I haven't even touched it (other than hooking up my Scangauge).

 

What engine modifications are you performing?

 

I'm having the head shaved for higher compression (hopefully >10:1), Edging the chamber, and cutting Singh Grooves, PowreLynz, and PowreRingz.

My experience lies with a 2000 2.5L Ranger with an automatic. Singh grooves were added and it was shaved to get compression back to stock. Mileage went up from 23 to 29 mpg and power went up to around 3.0 V6 levels. Here's a pic of that particular head. It doesn't have PowreLynz, PowreRingz, and hasn't been Edged.

http://powrehaus.com/2006/09/21/ford-25-ranger-head-w6-grooves/

 

I'm updating the original topic to include two more codes that came up when taking a 4 hour trip.

P0500 & P0219

P0401 came up again, and U0100 came up once while on the trip.

Edit: For some reason I can't update the original post so I'll just describe it here.

P0500 - Vehicle Speed Sensor Malfunction
P0219 - Not listed in DTCs.pdf...

 

According to the 'net, the P0219 is "Engine Over Speed Condition" which means I over-rev'd it down the highway. At what RPM will the ECU trip this code? In other words, what's the redline of my stock '98 Ranger 2.5L 4-cylinder?