[Rugb1]

Greetings
New here to the forum but joined cuz I've got a problem and questions too. Got into my shop, I'm an independent, a Focus that died on the road. Fuel pump runs, cranks but no spark! Finding no signal to the coil pack to fire the coils, but have battery voltage to the center wire. Replaced crank sensor, and checked the crank sensor signal right at the PCM. Also I notice the PATS light flashes really fast when cranking. I have no cranking RPM showing on my scanner. Codes set are misfire codes for cylinder 1 & 4. Checked fuses, been checking other things, any other ideas? Or is leaning towards a PCM? Does the PATS system have anything to do with the spark, or just fuel? What about putting in another PCM, does a dealer have to program it and relearn the key? Just a few questions I hope someone can help me with... Thanks a bunch

 

[sailor]

Fast flash of the PATS means it's not going to work until that problem is addressed.

Got another key avail. to try? Need one that's programmed into the car for it to work.

Doesn't address why it died to begin with, but you can't get anywhere on diagnosing that until the PATS issue is solved.

Low fuel pressure, particularly when the level is low is fairly common for one that dies. Scanner will give you that number, 40-50 for it to run.

Sounds like you know the computer gives an intermittent ground to the two outside wires in the coil connector to fire it when working right.

That pigtail to the coil is known for wire & connector problems, and the coils are almost a serviced item (bad when cracking seen) but those seldom die entirely for no spark anywhere.

Again, PATS light should go solid when turned on - goes off when cranking/running. Flashing means it isn't seeing a coded key it recognizes.

 

[Rugb1]

Yep tried another key and same thing, cranks fine but no spark. Again, does anyone know what the PATS system interrupts? Only cranking or will it shut off spark also like this one is doing? It has failed to crank a couple times in the past month, but then it cranks and runs the next time you try. Thanks again

 

[amc49]

Check battery for KNOWN good and charge. Could just be driven into dead battery when alt failed, they do quirky electrical stuff like you got. They can be dead enough to produce issue but sometimes still crank motor over.

 

[Rugb1]

Got it figured out! Had a bad coil. But also something else I finally found. It started and ran after putting a new coil on it,but still would sometimes shudder and die and would sometimes set a P0351 code. What I found was three bare wires that lie along side the EGR tube going from the front of the engine to rear, they had rubbed long enough that they would touch and ground out on the tube. This would interrupt 1&4 firing. Wires fixed and problems solved. Probably even had done it to the previous owner over a year ago. Thanks

 

[sailor]

Thanks for posting the outcome!