Crank, No Start, No Smoke, No Torque app readouts
 

I have a crank, no start situation. Have codes that translate to IDM communication error (P1668) and exhaust back pressure low (P0472). Changed the EBP sensor. No change. Unplugged the ICP sensor, no change. I hooked up the Torque app and the PID's that would tell me HPOP pressure, EBP psi, etc. etc. The app isn't reading anything but RPM. Do I have a bad IDM or IPR? No blown fuses either.

You are getting engine rpm? And the app does appear to connect?

Have you looked at the 42 harness where it crosses the driver valve cover?

Have you done any maintenance lately?

Yes getting engine RPM. App connects and reads RPM's but nothing else
No I have not looked at it. What am I looking for?
No maintenance

It sounds like you have a short or break in a wire killing signal. I would suspect fuel bowl heater but your getting the obdii to power up, attached is a pic of where the wire harness can rub on the valve cover. see the bright spot. Have you had intermittent problems or did this just happen. Truck been running ok?

.https://cimg2.ibsrv.net/gimg/www.for...bdc05c9a28.jpg

I will check. Thank you. The truck started sputtering and I took it home. It eventually would "choke" out and became a crank, no start.

Seems like all those sensors use 5 volt reference signal. Hopefully some of these smarter guys will come along and assist us.

What year, model, etc are we dealing with. do have a programmer of any kind?

The truck is a '01, F250 2wd. Bone stock. 250k miles

Sweet............

I checked the harness. Had a red/yel wire exposed. Patched it. No change. Should I be checking the IDM to PCM communication....EF open?

Ignoring everything else, focus only on that P1668 - IDM communication. If the IDM and the PCM aren't talking to each other, you won't get a 0.6 ms (or 600 microsecond) Fuel Injector Pulse Width with the key on. If you don't have that, no point in cranking because nothing's gunna work. This is looking like one of the fuses are blown. You need 5 volts for everything to work, but the 5 volts is made in the PCM from one of the 12V signals going to it.

I checked all the fuses over and over and the only blown one I had was a 7.5a trailer light. The maxis were fine, relays are clicking.....I'm at a loss. I consider myself pretty mechanically inclined and this is the first time I've considered having a garage look at it since I have ever owned a vehichle. I would like to fix it myself and certainly appreciate all the help. I will keep investigating as long as people are guiding me on here.

Something I failed to mention in this thread but put in the others was my oil was very low. I had never let it get this low before on any vehicle. I had some true bad maintenance practices on this oil cycle.I was embarrassed, ashamed, etc. Anyway, I had to add about 5 qts to the crank. Checked the HPOP res; it was full. I was also thinking maybe the IPR is stuck but TUGLY has me thinking about other wiring issues now.

One thing that confuses me is he's getting RPM. Wouldn't that indicate that the cps is getting the reference voltage?

Can you do a buzz test and see if we can get injectors to fire?

Can't do a buzz test. Kicks a p1668 code back