Aloha Folks,

I am having a heck of a time finding my ECU. 2004 f150 lariat 5.4 liter 4x4 super crew cab.

It was flooded up to the seats and middle consul. It has a 6 inch lift so the water didnt get in the fluids.

Electrical is working also, but it wont turn over. Changed the starter but still nothing. Bypass the electrical and it will turn over but won't run.

Im thinking the ECU is wet or shorted?

Any professional opinions would be appreciated along with the location of the ECU (Computer Module)

Mahalo

 

Do you mean the PCM Powertrain Control Module?
That is located on the passenger side upper firewall.

 

Hate to rain on your parade brother, but your front and rear diff and trans were submerged in water so you might wanna think about checking those fluids.

How long was it under water?

Stewart

 

I don't know how long ago this happened, but the electronics are probably shorted. Disconnecting and removing and drying out a lot of stuff will probably show all the corrosion and bad nasties. Electronics just don't like long/hours/days under water. As much of it is hot the shorts just create a mess of the stuff. Once you get it all dried up and the corrosion delt with can you run a code test to see what kind of code if any it throws. If power is to the Puter and it throws no codes, and the rig is dead you got real problems. Perty much everything you own on the rig needs to be drained, flushed until clean and refilled with good stuff. The gas may even have some bad stuff in it. In deep water, sitting there is just bad. You will need patience to deal with machine probably. Nohill for a climber though.

 

Shorebird: Thanks very much I found it.

Stewart: Thanks for the tip brotha. Actually it was a flash flood. I think the water was only up for an hour or 2.

Papa Tiger: Here's what I found today. I took out all the seats. The water as I said was only up for an hour or 2. Since I have a 6 inch lift the water did not get to any of the computers. The PCM is up high and was dry. Also i checked the body computer behind the back seat and that also was clean and dry.

I thoroughly checked the oil & tranny fluid and it doesn't appear water got in.

The one thing that got drenched muddy was the fuse box. We took out the fuse box and one by one dried and sanded them. We also used a compressor and air dried all the bits and pieces.

Is it possible that the Fuse box alone can stop the truck from turning over with the key, and also stop it from actually running?

Is there anything else that you guys can recommend I should do?

This place is awsome, thanks very much for all your comments and advice,

Michael

 

Just so the facts are clear:

All the electronics in the truck work fine, odometer, shifting, warnings, alarm system, lights, etc. I Can get it to turn over by hot wiring the starter but it won't idle or run.

it seems like something is stopping it from turning over with the key, and idling or running?

No Computers got wet, so In all your guys professional opinion what could be stopping it from turning over, and running? Fuse box was the only thing that I can tell got wet and muddy.

 

That sounds as if the anti-theft system is activated.
The pats is not sensing that a valid key transponder is present.
It may be as simple as the transponder pick-up loop in the column has failed. That happened to my '08.
You need to bite the bullet and have it transported to the dealer or someone that can access the computer to have it reprogrammed.

 

Ok so we got everything cleaned and dried. All the computers were dry as I said. The only electronics that were soaked and wet were the following:
Fuse box
Safety systems box (under center consul)

So the starter won't kick on everytime and you can hear a loud click everytime you turn the key on to start the truck, if you keep turning it off and on the truck will fire up. But it sometimes works and sometimes won't. We had taken of the fuse box and cleaned and dried every fuse and relay and let the whole setup sit in the sun for a couple days.

I thought it was the relay for the starter so I changed all 6 relay boxes (1 inch x 1 inch) but has the same problem.

Is it possible the computer just needs to be reprogrammed, or does this sound like I need to replace the fuse box?

Also the airbag light won't go off, could this be the safety computer thingy needs to be changed?

 

Check your codes. Document all the information. Reset your computer. Your codes will tell you where to look in the electronics. Check to see if you have 12 volts at coil and fuel injectors and if they flash. Check to see if your fuel pump run.

 

Thanks, ill do that and let you know what i find.