Hey guys

My neighbor, who is a Disabled Viet Nam vet, has a 2003 F150 w/ the 4.6L engine.
I checked the coils and are OK, but are not getting any voltage when cranking the vehicle.
Having some experience with ECU's, I decided to plug in my scanner and it would not communicate with the computer.
I did have success with another Ford truck and also, tried the scanner on my 2 Nissans with no problem.
I hesitate just to stick in another computer not having idea why this one failed.

Any suggestions??

The truck has about 200,000 miles on it.

TIA

 

Please , before spending any money , check all the fuses inside and under the hood.

 

Thanks for the reply
We did that while checking voltages.

New computer about $ 200.00 anywhere we checked.

Ford service say that the computer has to reset..whatever.

I just plugged the computer in on my Stealth and Firebird and had no problems ??????

 

There are two possible reasons for getting the results you are receiving where your scan tool will not communicate with the subject vehicle.
1. If there is no power to terminal #16 on the diagnostic plug, Check the fuse.
2. Your scan tool may not be CAN (Controller Area Network) equipped.
If it is, you will need to isolate the PCM from the network since there is a problem with one of the nodes in the multiplexing system.
This can get too involved if you are not familiar with the system and would best be looked at by someone with the proper tools and training.
One way to diagnose the system is to connect a DSO (Digital Storage Oscilloscope) to the #16 terminal and see if any data is being transmitted to the scan tool by way of the data bus.