Hello fellow Excursion lovers.

I have been experiencing some electrical issues lately, and I’m hoping to get some insight from people who know more about the electrical system than me.

I have a 2000 Ford Excursion Limited 4x4 with the 6.8 and 249,9XX miles.

Lately, I have had a misfire on cyl 8. I replaced all spark plugs, I installed a new coil, I swapped the new coil from cyl 8 to a known good coil from the other bank, and I still have the misfire. It used to throw the code P0308 cylinder 8 misfire detected and then a combination of the P0308 and P0358 Ignition coil H primary/secondary circuit code, and then P0358 Ignition coil H primary circuit/open (could be the same exact code and my scanner might’ve cut off the */open* part). Keep in mind no matter what other codes exist, the code P1000 OBD readiness test not complete code is always there but won’t put the MIL on the dash. Eventually, after toying with it for a while, all codes cleared and the misfire stayed after driving a couple miles ~10ish. To be clear the scanner did say no codes found.

Now, the codes reappeared but will not illuminate the MIL, but when codes are ran the P1000 and P0358 code persist, and the misfire is still there. Also, the wipers will wipe randomly, and sometimes will not work when I demand them. I see no signs of rodent damage/vacancy and don’t know what to start diagnosing or replacing.

I use a Foxwell Automaster pro scanner, so I’m unsure if I can test the functions of the ECM/GEM like some can with their Genesis or higher level scanners, I don’t think it is possible with my current device.

My biggest question is, do we think I should just order a new (programmed) ECM for the truck? I have heard some V10 owners did some sort of “ECM update” at their dealership, which is why I think the ECM could be the culprit. I have also heard the GEM module malfunctioning due to moisture causing wiper issues, but honestly, I don’t know what module runs what accessory, or if what I think is possible. I DID have the windshield seal rust bubble in the passenger top corner, but as soon as it was found it was sealed completely with clear silicone. That was 30,000ish miles ago while being used as a daily driver driving upwards of 100 miles a day.

I’m hoping someone else has diagnosed issues alike before I throw money at the truck.

Thank you for any future input on my situation and I hope for a new wealth of knowledge.

 

Here a resource for electrical diagrams. Navigate to Repair....Diagrams..... Electrical diagrams.

I would inspect the wiring for the bad cylinder.

Find out how the wipers are controlled.

It is not normal for a PCM to go bad, except for the 90s units with bad capacitors. Check everything else first. Your scan tool will display PIDs for misfires on each cylinder and much more. Keep looking at data and something may become clear. The codes are there get you looking for problems but aren't a diagnosis.

Forgot the link:
https://charm.li/Ford/

 

I have the same problem. Fixed the issues, and then started tracking down the garbage stereo system they put in the Ex and pulled it all out. Went to get in the Ex and now it runs like garbage and throws a P0122, P0042. Found a blown fuse, and found the tap wire for the stereo system on the tap of the Truck.

Fuel Pump works, all of the other stuff works - it just won't stay running after starting it. Already replaced the Throttle Position Censor - but I can tell you - that's not the problem

 

You did check fuel pressure correct? 30-45 psi 40 is the average.On it dieing out not this applies, but I'd be checking the Egr.While no ford guru, pull the vac line off,if problem stops,problem found.I know gm and typical issue, run poor,run and cut off.Granted this may not even be a factor.Thinking outside the norm

 

Make sure you don't have a windshield leak on the drivers side. I had one which would drip down the A post and onto the computer which caused all sorts of wierd electical issues including trying to start without key in ignition. Good luck!