Ford Repair Questions? Ask a Mechanic for Answers ASAP
Thanks for the great question.
Is the theft light flashing rapidly with the key in the run mode?
Does the engine crank normally?
How many miles on the truck?
Be sure to check all the fuses and the PCM diode. Test the diode with a diode tester or as a temporary test, remove the PCM diode and use a jumper to test only.
Verify that the PCM relay is working by swapping it with the blower relay, it should be the same relay. Now try and test and start the truck.
Let me know what you find.
How many wires coming from the PCM relay had 12v with the key on and what color were the wires that had 12v?
I didn't see where you check the diode. Were you able to test the diode with a tester?
I have put a PCM wiring diagram below.
The diode needs to be checked by swapping the leads. If your tester doesn't have a diode test, then check the ohms one way then swap the leads. You should have resistance one way but not the other way. You can also just jump the 2 terminals temporarily in the power box just to see if the truck starts. If it starts, the diode was bad and replace it.
Sorry here is the diagram. It did not show up in the last post.
Looking at that diagram there is no power to fuse 19 under the dash board. I'm going back to check that fuse. In case that the fuse is good what would be the next thing to check? Since after jumping power at the relay the ECM did power on and comunication with the scanner was achieved but still did'nt start. And when I checked power to the injectors I did not get ground pulse from yhe ECM only batt power to the injectors. And there is no comunication with the ATI-TEFT system
Be sure to get power to that fuse because that fuse feeds other circuits too which could be causing the whole thing. It might end up coming back to the ignition switch which would explain alot of things.
Let me know what you find out with the fuse.
LOL! been there done that bought the t-shirt and hat!
have a great day and yes I got paid! I do accept tips
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