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Hello. I have a 2006 3.0 Ford Escape that has a no start condition due to loss of spark to all coils. No stored or active pcm codes. I do have 12v on all front coils just no ground signal from ecm while cranking. Check engine light turns off while cranking so I’m guessing that means crank sensor is good. I’m at loss what I need to check for to get it running again. I’m limited on amount of tools I have. Just test light, multimeter, and obd 2 basic scanner. Thanks.
Last edit: 6 years 1 month ago by jon.lane. Reason: Vehicle fixed
Without a scope I would eyeball the crank sensor, trigger wheel, make sure the missing tooth is there. If during cranking the check engine light goes out that means the PCM is getting an RPM signal, but it doesn't mean the sync notch is there.
Can anyone tell me why there would be no check engine codes stored, this happened while I was driving the vehicle, thought it was fuel pump at first (no check engine light, no rough idle etc ever occurred). Coils appear to be separately fired by ecm I pulled it yesterday no strange smells was going to send it off to have it rebuilt but put it back in to do further testing as I talked to a tech that rebuilds them and he said that it would probably be a waste to send to them due to what it was doing. From my understanding it normally takes one bad coil to fry the rest and i have pulled them all and visually appear good, will test further in morning.
That explains that part. Had to put in new battery. Update just checked pins 1 and pin 13 at ecm. With no key in ignition they are showing they have grounds on both pins (test light lights) so I'm guessing that only means the computer is fried? Is my thinking correct?
I think a more proper test would be to install an ammeter in series with the load side of relay that powers the coils or injectors. Turn the key on, and if there's current flow to the coils when they have no business turning on you found your problem.
I Plugged in, if you had 12 and 12, that would suggest no ground at the PCM.
not following this reply. I have 12 v at front 3 coils koeo with test light grounded...it lights on red wire....no ground on other side while cranking
I was following up on your finding that the PCM was grounding your test light, at pin 1 and 13. I was saying that can't be if you have power on the red wire going into the coil, and power coming out, hence 12 and 12. I understand you're saying you have no control to the coils, correct?
Are there any other odd symptoms to this car? What was the last maintenance item? Did you check for any blown fuses? Why did you change the battery? Is it possible the check engine light going out while you were cranking something else entirely, like loss of power to the computer? Check the crank signal at the computer and if that's there I'm with Cheryl, time to check computer power and grounds. Seems like maybe Cheryl was 10 steps ahead of me
edit: Never mind on the crank signal, you already said you had scanner reporting 200 rpms. And you would have lost communication to the scanner if the computer lost power.
I see 6 grounds and 3 power feeds to do voltage drop on. See any I missed?
Correct no ground control at coils as that’s what I think Ecu is supposed to supply to provide spark while cranking on those pins. There’s obviously 4 more but figured since already is ground on those wires with key out of ignition that there is something wrong in ecu or am I thinking wrong?
Coil driver a and injector 3? With circuits unpowered you may be getting a backfeed. That ignition transformer capacitor is a path to ground too is it not? If you unplug that, does the ground go away?
My apologies, that was pins 1 and 12 not 13 my diagram i printed i need a magnifying glass to read numbers, thanks for the one you provided I did not have one that shows powers and grounds to the ecu. I will be testing all powers and grounds tonight hopefully.
jon.lane wrote: Can anyone tell me why there would be no check engine codes stored
My previous answer is probably incorrect.
I recall In one of Mr. Danner's videos he was working on a waste spark ignition with this same 36-1 trigger wheel as your car. That sync notch told the computer which pair of cylinders is at TDC and for waste spark, that was enough information for the computer to fire the coils. If the computer doesn't "see" this empty tooth in the trigger wheel you'll have no spark, an rpm signal, and no trouble code.
Your car isn't waste spark so it would have to know exactly which cylinder is at TDC compression when the empty tooth comes up so I think yours may need the CAM sensor to coordinate coil firing (I think). You don't have a cam sensor code but your computer still needs to see that empty tooth!
If your power and grounds checks are good I would look again to your inputs. Remove the crank sensor, check for damage and clean the mounting surface if it's rusted. Experiment with air gap if your screw hole is oblong shape.
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