Hey everyone,

Looking for some advice before I start throwing parts at my truck. Here's the situation:

The truck has always run great—smooth idle, strong pull. It’s a stock 7.3L with no tuner or ECU mods. I’ve done the Hutch + Harpoon mods and keep up with regular maintenance. About 300 miles ago, I changed the oil (T6 + Motorcraft filter as always). The fuel/water separator filter was replaced last year, and the RACOR pre-pump filter was serviced recently. I'm in Georgia, so icing isn't a concern.

The Problem:

Yesterday, I went out to start the truck to let it warm up like usual. It started right up, ran slightly rough for a second, but then the idle smoothed out. I went inside to finish getting ready and came back out 20 minutes later to find the truck had shut off.

Now, it won’t restart. It cranks strong and tries to start but just won’t catch.

What I've Done So Far:

• Replaced the Batteries: The old ones were 6 years old and clearly done. I installed new AGM batteries today. The truck turns over quickly, so cranking power is good.
• Checked Connections: The terminals (military style) are clean, free of corrosion, and properly tightened. I have 0-gauge cables connecting the batteries, grounds, and starter.

DTC Codes:

Here are the codes pulled with ForScan. These have been there for a while, and the truck ran fine with them in place, so I hadn’t gotten around to fixing them yet.

• IC DTC B1352: Ignition Key in Circuit Fault
  Fault in the ignition key circuit, possibly due to wiring or the ignition switch.
• IC DTC U1262: SCP Data Link Fault
  Communication fault between modules.
• PCM DTC P0472: Exhaust Pressure Sensor Low Input
  Indicates an issue with the exhaust back pressure sensor or its wiring.
• GEM DTC P1876: Transfer Case 2-Wheel Drive Solenoid Circuit Open or Short
  Issue with the solenoid circuit for the transfer case.

There's also a a fuel sender code (the gauge stopped working) but the truck's been running that way for a while now.

What should I be checking next? Is there something obvious I might be overlooking?

 

Check fuel pressure, pump might of taken a nap.

 

like this I assume?

 

There's a simpler way by using the fuel bowl drain, as the test port. But if the pump did die you can hear it if it does come or not if you can't hear when you do a KOEO tap and see if runs again, if it does your pump is dead, of not check to see if your getting power to the pump

 

I hear the pump coming on when I turn the key to ON position. It stops after the usual amount of time.

 

Gonna want to look at fuel pressure and icp pressure. If you have forscan going should be easy to grab.

Could also try unplugging the icp sensor, see if it starts - could have gone bad.

CPS can stop it from starting, and a commonish failure but w/ a 2002-2003 you cant test that by the tach. Have to use forscan.

 

The truck does not start (see video in top post), how can forscan test pressure/sensors if it won't start? There is not an ICP or CPS code in forscan under Errors.

 

The PCM has to see a certain amount of ICP before it will fire the injectors. That's what you are looking for. What it sees when the key is on and during cranking before the engine is running. There wouldn't be a code. That would make too much sense

 

I'm east coast, its 3:30 am, up in the middle of the night worried about this so I went out, unplugged the ICP and tried to start - no dice.

There is a little evidence of oil residue around the ICP and connector which seems bad. But no error and still no start with it unplugged. I took a short video of it:

 

I'm east coast, its 3:30 am, up in the middle of the night worried about this so I went out, unplugged the ICP and tried to start - no dice.

There is a little evidence of oil residue around the ICP and connector which seems bad. But no error and still no start with it unplugged. I took a short video of it:

 

If the ICP is oily, then it's time to replace it. Regardless if it is the cause of your current woes. They will get hydraulically locked up inside the housing and cease to function properly if the seal inside has broken and now there is oil everywhere inside the sensor.

 

I don't see where you say you've checked the engine oil level. If you haven't, check it before you go any further.

 

Forscan will show the ICP pressures during cranking. To eliminate one possible failure. It will also show RPM or not if it's a CPS failure.

 

Oil level is at the high/full mark, it was the first thing I checked. It was recently changed (200 miles ago) with Rotella T6 + Motorcraft oil filter.

 

Yeah you can even see the plastic upper connector move a little in this short 7 second long clip:

RIP wallet here comes another geniune Motorcraft expense...