Completely stock 2002 Excursion 7.3 with 105,000 miles shut off suddenly (no warning, no sputtering, no loss of power, just instant engine shut down) several times on my wife while she made a short trip. After it shut off the third time it would not start again. We left the vehicle over night on the shoulder of the road. I went back the next day with tools and a borrowed cheap scanner. It didn't throw any codes, but before I did anything else I tried starting it. It started and I was able to drive home approximately 6 miles. I replaced the CPS (Ford/Motorcraft OEM) the next day and started it to see if I drove it for a little while if maybe the issue had been resolved. I barely made it out of the garage and it shut off twice. I drove it back into the garage and it's been parked there for 6 months. Farm duties have slowed enough this time of year that I finally have a little time to try and fix it.

I tried unplugging the ICP and inspected it for oil and or frayed wires. I also tried starting it with the ICP unplugged. I then decided to purchase an OBD II to USB adapter and Forscan Lite for Android. I ran the scan and the following codes were found:

Instrument Cluster
Initially got a U1262 code; I then ran an instrument cluster test and gave an additional code: C1284

PCM
P1280 Injection Control Pressure Sensor Circuit Low
P1000 On-Board Diagnostic (OBD) Systems Readiness Test Not Completed
P0603 Power interruption on KAPWR circuit
P0340 CMP circuit fault
P0470 Exhaust Back Pressure sensor circuit malfunction

Batteries are new from NAPA and fully charged. Also, I was not able to view any of the sensors readouts in the Forscan app, not sure if that has anything to do with the no start or if something needs to be changed in the Forscan app settings.

 

You've done alot of good troubleshooting to this point. That P0340 code points to the CPS, so it may have been giving trouble. Sudden shutoff is often due to either the CPS going, or the IPR getting hot and going open circuit. If it starts fine cold, but not hot, the IPR coil is suspect.

How is the engine oil level?

Check the IPR for a loose tinnerman nut - make sure it's on tight. P1280 is complaining about the ICP or IPR usually. You've unplugged the ICP and still have the issue, so leaning towards the IPR or IPR wiring. Also check the CPS pigtail for frayed/shorting wires.

Check the link below to set up FORScan Lite to monitor engine PIDs.

https://www.ford-trucks.com/forums/1...d-q-and-a.html

Recommend clearing all the codes and taking the rig for a short drive if it will do so, then check to see what comes back.

Where did you buy the motorcraft CPS? Unless it's from a reputable seller, sometimes knockoffs are sold in apparent OEM packaging - there are clues if it's fake: grammar or spelling mistakes.

 

Thanks for all the tips! I already made sure of the IPR nut, forgot to mention that I already tried that. When I first did the scan it had a couple additional codes but I figured at least some of them were due to the fact that I had disconnected the batteries to replace them, as well as disconnecting the ICP sensor and IPR sensor. I cleared all the codes and then ran the scan again and the codes that were present after the second scan are what I listed above.

Unfortunately it won't start at all or else I would have cleared the codes and drove it around to see what codes were there after driving. I will have to go take a closer look at the IPR wiring and the CPS pigtail, not sure I looked at it too closely when I replaced the CPS. Also, thanks for the info on the setting up FORScan Lite

 

That U1262 may be a 2002+ code. I'm not as familiar with these, but see the thread below and see if you have some of the additional symptoms listed.

https://www.ford-trucks.com/forums/1...ode-u1262.html

Noted on another thread that C1284 may not be valid if the engine is not running:

===IC DTC C1284===
Code: C1284 - Oil Pressure Switch Failure
Note: This code may not be valid. Re-run the Self-Test with the vehicle running to verify the code.

Module: Instrument Cluster

Diagnostic Trouble Code details

Oil Pressure Switch Failure

 

OK, since you are still getting P0340 after clearing codes - need to see why the CPS is not working. You can monitor RPM in FORScan during cranking, and see if you see cranking RPM - that would tell us if the PCM is getting that CPS signal.

 

How does your engine harness look over the driver's side valve cover? Sometimes it can chaff on the cover and short wires causing a stall. A good preventative maintenance check regardless.





Would love to see some pictures of your rig - that sounds like a low mileage beauty.

 

I set up the recommended PIDs in FORScan and went out to the truck to crank it over and see what the sensors were reading. The IPR started at 14.84% and never changed. The ICP went from 40.2 psi to a max of 458 psi while cranking. The Engine RPM never changed from 01/min the entire time, assuming that means the CPS is not reading anything because obviously I can hear it cranking.

I'll have to see if I can upload some pictures of the truck. You are correct it is an unmolested survivor, pretty good condition. I tried uploading pictures of the FORScan app screen I had taken with all the PID values but the uploader got stuck at 90% every time.

 

I believe it takes 500psi before the PCM will command firing the injectors.

I would think the IPR% (command) should continue to increase until it sees a good pressure. I find this suspicious. But I have not used FORScan so just shooting from the hip until the experts get here.

 

Thanks for the response. I cranked it a second time a little bit ago and ICP went to 625 this time but no change in IPR or RPM values.

 

Is the new CPS fully seated? Sounds dumb, but that can happen. I watched Timmy from suffer an expensive offroad tow from that.

 

Thanks for the response. Yes it’s completely seated. I actually swapped the old one in this morning to check and see if it made any difference in the RPM reading while cranking. I have the new one back in now and it’s nice and snug.

 

Just realized we are talking about an ‘02!
I believe there was a change that year and no tach movement is normal? I am an OBS guy, but some of the SD guys will confirm.
https://deadheaddiesel.com/cam-position-sensor-7-3-cps/

 

Based on what I have read I believe you are correct that the tach on the instrument cluster not moving on a 2002 but the RPMs I’m referring to are from the FORScan data and it should show something if the CPS is communicating with the PCM. I could be wrong but I think that is the case.

 

Sure seems like the CPS signal is not getting to the PCM, so the PCM does not command the IPR above 14%. I think that signal passes through the 42 pin connector on the driver's side. Did that harness over the valve cover look ok? Wondering if that's where the CPS wire is broken/shorted. The other check would be to see if you have VREF (5V) on the center pin of the CPS harness with the key on.

From the attached CPS information from Riffraff:



Diagnosis of the CPS is pretty straight forward. Using a diagnostic tool like AutoEnginuity Total Ford Enhanced Bundle [or FORScan] select Engine RPM and watch the readout as you crank the engine over. If you get an RPM reading, your CPS is more than likely working correctly. If you do not get the RPM reading, you need to perform a continuity check on the wiring to ensure you don’t have an open circuit. You can disconnect the PCM plug and use the pins called out in the diagram above to verify continuity. Once you have verified that the wires are not open, you can reconnect the connector to the PCM and verify you get 5 VDC with the key on, engine off on circuit 351. If your wiring checks out, you are pretty safe to say that the CPS has failed and you need to replace it.

 

I used a multimeter and put the red probe on the center pin of the CPS connector and the black probe on the ground and got 4.99 Volts . I attached a picture of the packaging the CPS came in. The vendor on eBay (I know this could potentially be the problem) was overstockdirectus which had 100% positive feedback. Could it be a knockoff? Also, could someone direct me to a reputable place to buy a legitimate CPS? Also, is the part # correct for the CPS that I ordered?

Edit: I suppose I should still do continuity test on the CPS signal wire 🤦‍♂️