Ford Repair Questions? Ask a Mechanic for Answers ASAP
Hello and welcome! My name is ***** ***** I can assist you with your question. What size engine do you have? Does the engine crank over but not start or does it not crank over at all?
Ok, does the engine have spark when cranking? Does it run on starting fluid?
Does the check engine light come on with the key on and does it go off while cranking?
Ok this is the problem. The computer is not awake and therefore the engine will not start and run.
The next step is to check all powers and grounds going into the computer. This includes all powers from all fuses, fusible links and even the ignition switch.
The computer is under the hood right side of engine compartment
One minute while I get you a pic
It is number 52 in the pic
Right.. but that does not mean it has power going to it.
They are for a lot of various other components on the vehicle. However, relays usually do not prevent the engine from starting.
YES, that is correct.
YES, I did. Which fuse does not have power? Keep in mind, sone of them will not have power and this is ok.
Do you have an auto or a manual transmission?
According to my wiring diagram, that circuit is only for a vehicle with manual trans
Here is how to diagnose this condition.
Check for battery voltage on the solid Red wire that goes to the Idle Air Control valve. This is the same wire that powers up the PCM at pins 71 and 97 from the PCM power relay and feeds power to the primary side of the fuel pump relay. If no voltage is present, check for a blown fuse. Fuse 24 in the Battery Junction Box is a 30 amp fuse that should be hot at all times and feeds the secondary side of the PCM power relay. Fuse 30 is in the Central Junction Box (CJB) and is a 30 amp fuse that should be hot when the key is in the run position and feeds the primary side of the PCM power relay. Also check fuse 18, 15 amp fuse which is between the PCM power relay and the injectors.
I am talking about the power circuits in my last post.. not grounds..
Ok, no problem. However, I dont understand your question.
Sure it could be a bad ground, but we need to check them (and the powers) directly at the PCM with the key on. Please do this and let me know what you find. Going to get some sleep. Talk to you in the morning!
I'm in eastern time zone
Hello! That is great news that the engine has started right up this morning! Lets hope it continues to start and run. If not, at least you now know what to test/check for when this condition occurs. Electrical components can and will do this when they start going bad. I see this all of the time working in this field. Intermittant issues are a mechanics worst nightmare
The PCM is a possible cause and they do bad bad. However, this is the last thing that should be replaced for this problem. Everything else needs to be checked and ruled out before the PCM gets replaced.
I am glad I can help!
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Please let me know if you have any further questions.