So I drove a 8 hr trip yesterday with no issues. Made a few short trips today and the my 2005 6.0 died out of nowhere. Pulled the codes and I’m getting a P2291 code ICP too low-Engine Cranking.. i checked the oil and it was low so I added some in. Truck turns over and is not locked up. No smoke or anything from the exhaust pipe. Just cranks and cranks. Checked the ICP values while cranking. The ICP Voltage range is 0-5 but shows 0. The ICP injector pressure is 8785. And the IPR regulator shows 60% and another time the reading was 94%. I unplugged the ICP and there is no change at all. Injectors have been replaced within the last year. I’m leaning towards it being the HPOP but don’t know for sure or have anyway to single that out. What else could I check or try? I’m stuck out of state with it right now until I get it figured out. Thanks for any advice or suggestions.

 

ICPV at KOEO should be .18-.24v

8k plus ICP suggests sensor whacked
out that’s reading around double max pressure

what you reading codes values with

do you have 5 volts VREF

 

I tried to unplug the sensor but it still didn’t start. I thought I read somewhere that if it was bad, you could unplug it and it would start and run rough then die. I will run the test again tomorrow morning and see what it reads.

I’m using my FORScan on my phone. I didn’t check the vref reading

 

Pulling numbers and codes is appreciated, but you are leaving out a bunch of necessary information.

Cam/Crank Sync when cranking?
FICM Sync when cranking?
Cranking rpms?
Fuel Pulse Width when cranking?

What units are your ICP numbers in ..... kpa or psi? 8785 psi is TOTALLY unreasonable. If it is in kPa, then it is somewhat in the rage of something that the PCM MIGHT be "assuming".

Yes, unplugging the ICP can SOMETIMES help an otherwise healthy engine to start, but you seem to have several issues going on (not JUST a bad ICP sensor). Also, the PCM will sometimes assume a good ICP number when cranking. It does this when it thinks there is something wrong with the ICP sensor. The reason it does this is to help the engine start, but it helps IF (and only if) there are no other issues.

When voltage output from the ICP shows problems, then you obviously need to go a step further in troubleshooting and test/verify if it is actually a problem with the sensor, or if it is a connector or wiring issue.

You are leaning towards an HPOP, but the '05 and up HPOP is not commonly a failure prone component. Yes it can fail, but not real often. There are still SEVERAL possibilities that are more likely to be the root cause than the HPOP. You could have a bad IPR valve, or you could have a failure of the HPOP's discharge (STC) fitting ........ if the fitting is still original.

You said the oil was low, so please tell us how low.

ANYWAY - if you determine that the ICP sensor connector and the wiring is good, then install a new (OEM from a dealership) ICP, and then repeat the cranking test.
Post the new data, and the units of measure for the data, when cranking.

It might help us help you if you posted a picture of the top of your engine.

Be prepared to do an air test for leaks in the high pressure oil system. In your case, I would recommend you getting the IPR test fitting to use for the leak test. This involves pulling the IPR valve, so read up on that. Testing through the IPR valve port gives you the opportunity to inspect the IPR valve after you remove it. You should also test the resistance across the IPR valve contact terminals. NOTE: You MUST have a special test fitting if you are going to do the leak test through the IPR valve port.

Oh - and you also need to buy the specific IPR socket for pulling the IPR valve!

You could also test from the ICP port, but this test requires you to have a KNOWN GOOD IPR valve, and to command it closed during the air test.
Remember that the IPR Duty Cycle is a command only. We do not have a way to know exactly what the valve is really doing!

Also, you might want to read the thread below:

https://www.powerstroke.org/threads/...#post-16657928

Some good videos on the subject:

 

Thank you for the info. I did not check the cam sync or Ficm sync but will test that today. The units for measuring the ICP was set to default with kPa and I didn’t realize that until later.

For the oil, it didn’t show any on the dipstick when I checked. I added in 3 quarts and it was to the top of the dipstick. I will look through the videos and do some more research. I don’t have access to air since I’m stuck out of state unless I take it to a shop unfortunately.

 

IIRC An ICPV of 0v and a ICP of 8785kpa or 1274psi seems like default value (ICP Unplugged). Was the ICP sensor plugged in at the time of reading??

make sure everything is plugged in and hooked up when you get sensor values

I’m leaning towards a leak or delivery problem too but we have to make sure about your ICP sensor and the rest of what values Bismic asked about

 

I’m it sure now that it was plugged in for those values. I also ran it another time and the values were icp voltages .24, icp pressure was 0, ipr % was 94. I took screen shots when I ran the test. Not sure exactly if I had it plugged In. I’m going to tow my truck to my hotel today and then try to figure it out and will rerun the test.