**Final update (to save the long read for those of you with no patience) bad ECM, ordered new one programmed to my VIN with new uncut keys from ebay for $330.

I'm posting this more for my own sanity and logging than anything else, so I don't expect anyone to actually say "hey this happened to me also, it's your flux capacitor!"

Someone always says more info is better than not enough, so here goes: 2006 Ford F150 King Ranch 5.4 2wd 2 tone Copper with EXACTLY 112,000 miles on Wednesday morning. New engine was installed by dealer at around 70k miles (I think it was 68k and some change). No real problems since they fixed the dozen things they left wrong after the install. Oh, and I did a psudo GOTTS mod on it, putting a stright pipe in place of the silencer. I did a post on it here, somewhere. Otherwise bone stock.

It's been raining off and on (el nino, right?) but nothing extreme yet.
It only lightly sprinkled on Tuesday night
Wednesday morning went to start my truck to go to work and nothing. Key into ignition, turn, nothing. No starter. No crank. I can hear a click coming from the fuse box, none of my interior lights dim, nothing on my dash display looks different than normal. It just won't engage the starter. Security light is solid not blinking. My first impulse is "not the battery"
I checked my shifter, key is still in ON, so I'm able to move from Park to Reverse, Neutral, Drive etc. No start in Neutral also. Called work to say I'm not coming in today.
I go inside and grab my trusty Innova code reader (sorry, don't know the model off hand), plug it in, key on, engine off (since it won't start obviously) code reader turns on by itself, as it should, scanning, scanning, scanning, "Unable to establish link" (or some such wording). Isn't that strange I think...
So I go to check fuses (not sure why, I've never had a bad fuse before) and I pull out my weathertech floor liner on the passenger floor then set my hand on the carpet and whoa, it's wet!! Floor liner is dry as a bone but the carpet underneath is wet. What magic is this?
Then I pulled the door sill up and stood the carpet up, pulling it from the fuse box corner toward the seat. I see a huge bundle of wires (I've never looked in here before) running down a channel in the floor of the truck that's about 1/2" deep in water.
Disconnected the battery then used a shop vac and a towel to get all the water out, then I found the drain plug underneath
About a half hour later I connected the battery, climbed in and she started right up!!
I let it run for a good 10 to 15 minutes and I look at my watch. It occurs to me that I can still put in 7 hours at work so I turn it off, go inside grab my lunch and come back out, started it up and put it in drive. Pulled forward about 15 feet and it shuts off on it's own. Tried the key a few times and NOTHING again, same as before, no crank. Good thing I didn't call saying "on my way".
Pulled battery cable and started spraying water all over passenger front of truck to see if I could find the leak. Nothing. Sprayed the A piller, sprayed the entire left side of the windshield, the cowl area, inside the firewall, the wheel well... nothing.
Checked the battery it with a volt meter and it's showing 12.2x volts so I put my trusty charger on it at 10amp charge. Charger shows it at around 75% so I go inside and start googling "F150 no start" "F150 water on floor" etc... 20 to 30 minutes later I come out and the charger is bouncing a little between full and 75%. Now I'm thinking "maybe battery?" I pull the charger get a ride down to Costco, exchange my battery for free.
New battery installed, truck starts right up. YAY it's fixed! Grab a check I need to put in the bank and drive across town to the ATM. I get 3/4 the way there and poof, truck shuts off while I'm driving. This was my first time negotiating this pig into a turn with no power steering. I don't recommend it to anyone. I made it into an empty parking lot safely.
Now I figure it's time to use my "phone a friend" card. I call the most awesome real mechanic friend I have to ask his advice. Here's the summary of what he and I think, in my words because I don't have a perfect memory:
-Code reader not working when it won't start means the CAN bus is not able to talk to the computer
-The computer communicates to the sensors on 5 volt lines aka the CAN bus
-Cross talk across these 5 volt lines causes all sorts of strange problems (on different cars in his experience)
-A failing sensor throwing a bad voltage on the 5 volt line "CAN bus" will cause this, examples he's seen are bad MAP sensor, bad TPS sensor even bad air bag sensors.
-He's seen a misdiagnosed "bad ECU" many times that turns out to be similar to mine. Something is overwhelming the CAN bus.
-My water on the floor may or may not be related
This conversation lead me back to earlier where I read a few reports of no crank no start caused by a bad TPS sensor. Not knowing where my TPS sensor was and seeing 2 different sensors on the top of my engine I figured 50/50 and I unplugged what I later realized is my MAF sensor. It's located on top of the air filter on the drivers side of the engine for those that care.
The entire time I talked to him I had my battery unplugged. I know plugged my battery back in and it started right up. Lets get to the bank!
I drove a whole 1 mile, the truck went into limp mode (or whatever it's called) before I left the parking lot, but I made it all the way to the bank. I parked in the back just in case it wouldn't start back up and I shut it off.
Deposit check, back to truck, key in and NOTHING.
So I plugged the MAF back in and tried the TPS. After 5 to 10 minutes for the memory to clear I plugged the battery back in and it starts. To my horror I realized the TPS is also my throttle. My friend mentioned he wasn't sure what year Ford went to "fly by wire"... in short I have no throttle.
Pulled the battery cable again, plugged my TPS back in, unplugged the MAF thinking "it worked once, where's the harm?". Waited and plugged the battery back in and VOOM, it starts again.
I drive home, this time I stopped to buy a new MAF sensor, stopped again to add some gas (i usually fill up, but the pump at this cheapo station on my way was running so slow I just couldn't wait any longer) and both times it started back up.
I get home call my friend and he's confident it's NOT my MAF sensor (because it still failed at my bank with it unplugged) and I agreed, but I was really wishing it was that easy....
He said we shouldn't overlook the obvious, the water on the floor. Those wires in that trough were underwater for sometime. Also if there's water there, where else is there water at? Any failing sensor, or crosstalk on that 5 volt line will send the ECU into "oh no you didn't mode" so for now I should plug the MAF back in and try to dry out the truck. So I plugged the MAF back in, dialed my heater up to 90* put it on floor and let her run for about an hour. The wires all felt dry as a bone, the carpet, still pulled back away from the door still feels wet, but not enough to drip anywhere. The passenger floor is dry.

Thursday morning, I drive into work heater on high, no problems

Thursday evening, it's raining out (light showers?), I drive home, heater on high, no problems. Checked the floor, still dry. Checked the firewall, still dry, checked the cable trough still dry.

Friday (today) I drive into work, no problems. All areas still dry, of course the carpet is still wet, but not any wetter than it was yesterday and not wet enough to drain water anywhere. Also it's still pulled up somewhat so if there is water draining down the firewall it wouldn't touch the carpet right now.

**Most likely unrelated my drivers side tail light failed a few months back. New light bulb lead me to discover the tail light socket did not have power and looked burnt. When I pulled the socket out I tested and found the cable did not have power either. I probed the line an inch down and still found NO power. So I traced the line and found it had power were it plugs into the harness. Must be a cut in the wire somewhere. I ordered a couple new sockets and pulled a new wire and jumpered it onto the existing wire. Viola! tail light working. The only reason I mention it is because that same tail light stopped working again about a week ago. I need to get back in there, hopefully it's just a bulb this time, but that's a fast failure if it's just the bulb.**

Way I see it, I've got 3 problems and no idea if any are related:
1) No start, no crank, no way to read codes when it happens that may or may not be fixed all on it's own.
2) Water leak on passenger floor that is bypassing fitted floor liners (must be coming down firewall, down from center of truck aka center hump or through the passenger seat)
3) Tail light harness shorting out drivers side brake light and turn signal. (tail light problem unrelated, now fixed)

I think that's everything.

 

I read most of it, I didn't have time for the whole read. But I didn't see if you checked your fuel pump driver module. Have you?

 

No, I've never checked it, but fuel pump driver module couldn't cause no crank could it?

*edit* Just finished reading about it...
I will drop my spare and check it as soon i'm up tomorrow. Fuel pump driver failure couldn't cause the no crank I've got by it by itself, but if the electronics are exposed and it's shorting the 5 volt bus to the ECU bingo! If this is my fix I owe you big time.

 

You're right, that shouldn't cause a no crank. The truck would just act as if it were out of fuel when you'd try to start it.

Still worth checking either way, it could be part of your problem.

 

Just pulled it out, visually looks perfect. Aluminum body shows no signs of electrolysis plastic is in great shape. Where to look next...

 

I'm not sure on your "no start" issue, but the first place I'd check for a water leak on your vintage truck is the CHMSL. (Otherwise known as the third brake light.) Ford had a number of issues with those leaking.

 

Youtube video, no crank, no start, no codes is pointing me at relay 203, the master relay for the PCM. I pulled it and visually mine looks fine, the one in the video had green corrosion (he called it boogers, gobley gook, all sorts of fun names) but I swapped it out with 201 since I'm not towing anything. Now to drive it around and see what happens.

Oh, forgot to mention, it failed again last night (Friday 1/15). I got out of work put the key in, turned it over and nothing. Pulled the battery cable a couple times and it started working again. Got home and it died right as I pulled in. Couldn't have timed it better that time.

 

Check the battery cable at both ends to make sure it is making good contact!

 

Battery cable is not the problem. I'll double check just to be sure.

New symptom or newly discovered symptom:
When it won't start, if I leave the key in the ON position for about 10 seconds I hear a beep and then the starter will spin if I turn the key to "start". I did this about 8 to 10 times in a row, so that seems to be 100% consistent so far. Sometimes it starts under these conditions, sometimes it won't. When it starts, it only runs for a few seconds, then it will not crank again. When it won't start, it's acting as if it's got no fuel or spark and if I turn the key OFF and back to ON, usually it won't crank again, but sometimes... just sometimes it will, but then it only runs a few seconds. I need to locate a map of the CAN system so I can start ruling out a possible bad sensor shutting down my CAN bus aka root cause.

 

No start, no run, run, die, no start... Round and round I go.
Started troubleshooting the PCM, my code reader fails to read it when it won't start, so I thought that's a good place to start.
I'm getting 11.5 volts on the #3 plug koeo, my googling says I should see 5 volts. It's got full battery voltage when the truck runs though (13ish). #6 sees 2.6v and #14 2.51.
After pulling the harness under the drivers seat (troubleshooting the voltage on #3) I eventually started it back up after plugging everything back in and I'm seeing P060b and P2107. This points to PCM...

 

Found the water leak. Looks like some knucklehead cut the rubber boot behind the fuse panel. I'm going to pull the entire fuse panel out tomorrow morning.

 

Yesterday:
Entire fuse panel removed, inspected, cleaned and all fuses, relays and connections greased (dielectric grease) then re-installed. RTV'd the hole letting water in. Truck running good last night

Today:
No crank again.

 

Did you find any corrosion when you removed everything? The problem with corrosion in an electrical system is that once it starts, you pretty much have to replace any corroded parts since the corrosion resistant coating(s) have been compromised.

 

None. I wish there was a good way of testing the PCM other than just replacing it.

 

Starting tracing the purple wire on the PCM plug, #3. I was getting between 11.5 and 11.9 volts leading me to believe there's stray voltage from somewhere. The other thread I started on this subject asking for the wiring diagram says I should be getting battery voltage on this wire at KOEO.
Before I realized that I went through the truck and unplugged every where I could find that purple cable to no avail.
I started pulling fuses while I watched the voltage of this wire.
Once I pulled #5 fuse my voltage dropped to 5.9v.
I've plugged everything back in but something else is wrong now. I'm getting 10 volts on the purple wire, the truck starts (could just be working for now, remember the problem is intermittent) but I have no console info. Tack, Odo, Oil pressure, Temp, etc all dead. Instrument panel does light up though. Also the dome lights don't turn on and my radio also doesn't turn on. I checked and double checked all the fuses but none seem to be bad.