2002 F150 Lariat Super Crew, 5.4 L, Auto, 2WD, 210K at the time. Purchased at 185K

Doing this write up since this problem is why I joined this forum.

Background, got into fixing cars working on a Volvo 245DL and making use of the Brickboard forum. Done everything but a engine or tranny pull. UTube has been my friend up until this issue.

Tools used:

Search Function in this forum
DVM
Code Reader
Shop Manual
Owners Manual

Problem started on a warm day about two months ago on the way home from work. Walked out after stopping at a store and the engine would turn over, but did not start. Knew I had a tight spot on the fuel pump that cycling the key would fix. This time cycling the key did nothing, crank no start. Opened the hood and swapped out the fuel pump relay with a same part, and then changed out the fuel pump fuse #10 with a new one. Got back in the truck and it did fire right up. This was not over.

Next day same issue, letting the truck sit for a few minutes would let it start.

Figured I had a fuel issue since there was a tight spot. But never had a weak fuel pump let the truck run fine after it started. So was pretty sure that this was not it but spent an afternoon changing it out.

Went down and got an aftermarket fuel pump and watched a UTube video on how to change it. The truck in that dang video was a extended cab, and he pulls the bed and changed it with the tank in the truck. So I used some ropes and an engine hoist to lift off the bed and then to set it aside. The Super Crew has it under the cab so all that effort was wasted. Dropped the tank and replaced the fuel pump, got the bed back on and went for a drive. After the engine warmed up, same issue.

Did a search on here and found the word PATS, Passive Anti Theft System. If you don't have a signal from the PAT's the truck will not start. There is a very good detailed write up I can't seem to find now on how all this works. Short version is there is a inductive coil around the key that reads the chip in your key and transmits it. If the code in the key read by the PATS matches the info stored in of all places your instrument cluster, then the ECU sends out pulses and the engine starts. If the PATS does not work you get all dashes across the Odometer.

Walked out, took it for a drive to warm it up and what do you know all dashes on the OD when there was a crank no start. When the mileage showed up start ever time. All dashes and crank no start.

Figured it was the PATS Module, so called a local Ford Dealer to order a new PATS Module and he wanted $125 and had to order it, or I could pick one up from another dealer in town for the same price. From my Volvo days I knew about a online Volvo-Ford Dealer in Cranston Rhode Island. They had one for about $25 bucks and shipping to Texas was $8. Waited two days and it showed up.

During that time a new problem showed up, I was driving down the street and suddenly the OD had all dashes and the engine died.

That told me it was not PATS. PATS will not cause an engine to suddenly die, just a no start. Waited for a long time and it did restart and made it home. Pulled out the code reader and what do you know, No Module Present. Waiting for it to cool down and got the mileage on the OD. The code reader got right it and I read the VIN.

So now I was looking a bad ECU or a power problem to the ECU.

Got a box of fuses and stated checking continuity, then came to my senses. There must be contact on these fuses or it would not start cold. So put the DVM back in the tool box.

Pulled out the owners manual and the shop manual which i have a copy of and got to looking at power diagrams.

Solution, Changed the 40 amp fuse 111 (40 Amp) and fuse 18 a 15 Amp.

Engine started and after long drive, kept starting. The problem is fixed and has not happened again for two months now. No more tight spot on the fuel pump, she fires right up every time. So changing the fuel pump was not all wasted.

I do have a brand new PATS unit if someone in the Houston area needs one.

I have not bothered to install either of the questionable fuses to figure out which one it is. My bet is on the big old 40 amp fuse but that is a guess.

Hope this helps someone.

Regards,

Paul

 

Thanks for taking the time to share all of this. Haven't had this issue with my '01 yet but I'll have a good idea of where to look first.
Thanks again.
And yeah, pulling the bed off of a SuperCrew to access the fuel pump was a slap in the face, huh? Been there...

 

LOL on the bed removal! You didn't crawl under there to see where it was first? And once I spent a full day, 2 alternators, relays, checking fuses, etc. Trying to figure out why my 97 4.6 wouldn't charge and left me stranded 40 miles from home. Ended up being a 10A mini fuse in the dash that controlled the airbag. No kidding. Freaking airbag fuse won't let your alternator charge. Grrrr.

 

No i did not crawl under and look, I did stand there with the what the heck look for a second once I sat the bed down. I do have side bars, ended up having to pop up the pumpkin to get that tank out of there. Having the bed off did make that part easier.

That is my story and I am sticking to it.

 

My little brothers truck likes to do this every so often. I might have to give it a once over when he comes back around. Thank you for this write up

 

So, do you by chance know which model year truck your referring to?

 

2002, sorry about that

 

Thanks Paul...... but........ I must be missing something.

What is fuse 111 and fuse 18?? What do they service?? What was the problem??

Sorry but after reading your whole post I don't understand what the problem was and what was fixed other than fuses 111 and 18 were replaced.

Thanks for any info.

I am attempting to help a friend of mine with a 2003 F150 4.6L and knowing what those fuses service and what issue you resolved may help us figure our problem out.

Thanks again!!!

 

- Funny, I've only heard of folks removing the bed for this on the internet. Bed removals on any of the 97-03 models is crazy for a fuel pump swap. All that extra time vs just dropping two straps. A FP change out goes very quick with a little WD40 (or allot of lol, - it's a must !).

If you have to siphon some fuel, - same thing EASY! Hit the the rear vent w/WD,- turn counter clockwise one 1/4 turn ...pop right out. Now you have a 1.5" hole to siphon from.

 

Yea, you can't use an 02 manual for an 03,- or any other model year for that matter. Ford changed fuse locals/sizes with every model year. Actually the 02 is a special sort truck, -had a few experimental differences from 01 that didn't find their way onto the 03 models.

Best thing to do is head over to Motorcraft.com and download your owners manual (your model specific) . It'll have the info (correct info) your looking for.