06 Click No start Check Gauges
 

06 F150 5.4 4x4 xlt scab
Turn key it clicks once doesn't crank dash says CHECK GAUGES. All individual components are good/new or test good.
Plug in obd2 scanner and it says it fails to communicate with vehicle.
I'm thinking my PCM/ECU is fried but dont know how to confirm that without spending precious $ I dont have.
PLEASE HELP

Battery is good?

Battery is good, all fuses are good, all relays test good with ohmmeter and 12v power, brand new starter and ignition switch,

Does your obd jack have pwr
 

Fuse 41 same as cig lighter .Does your pcm have pwr ..There is a pwr relay for pcm . The start relay is controlled by the pcm supplying grd . What is your dash light for pats doing . Of course nothing is going to work if pcm not fired up. But you have to have good grounds too . Grounds in left and right kick panels should be cleaned corrosion quite often does these in . You can use jump cables from battery neg to supply different frame points etc a ground to help figure it out ..
Getting the pwr ro pcm and ground to get obd to talk is high on the list .I can send diag on start circuit.But that ground signal has to come from pcm which isn't going to happen unless its powered . In fact almost all circuits are powred by a grd from pcm ' Ground points are just as important as the fused side .
How is your headlights working thats a load test for battery and fuse panel .
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Next I will have to locate pcm diag for the the test to see if all grounds and pwr is at pcm . No sense buying a pcm and still not powered up ,that's a lot of trouble .

2 dumb questions, is the ign tured to the 'On" position when trying to connect to the OBD? Also, are the battery cables snug?

Could also be a bad alternator, loose connections at starter/alternator.

Clean the terminals and load test the battery. If I had a dollar for every time I was told "battery is good"......
And the battery itself may actually be fine, but the current has to make it through the terminal clamps.