Ford Focus Forum, Ford Focus ST Forum, Ford Focus RS Forum - View Single Post - DTC P0351 - Ignition Coil "A". At the end of my rope.
View Single Post
Old 03-26-2007, 06:40 PM   #1
superbeast04
Focus Rookie
 
Join Date: Mar 2007
Fan#: 45439
Location: Edmonton, AB, CA
What I Drive: 2001 SE

Posts: 3
FF Reputation: 1 superbeast04 Good Standing Member
Buy-Sell-Trade Rating: (0)
DTC P0351 - Ignition Coil "A". At the end of my rope.

Hey all, this is going to be a fairly length post, but then again, I've spent a VERY long time trying to fix this problem.



I'm sure many of you have heard of the issue with the wires breaking at the ignition coil connector. Well, this is just like that, except replacing the connector didn't fix the problem. Have a read through, if you have ANY suggestions on where I need to go from here, PLEASE PLEASE let me know.



I'm pretty much out of options... and I'm NOT the type to give up or ask for help lightly.



1. Symptoms starts
a. DTC: P0351 only
b. Heavy jerking under acceleration as car switched from 2-4 cylinders. Drops for ½ second, comes back, does it again
c. Rough idle, cylinders 1 + 4 not firing, tested with spark tester
d. Occasionally symptoms will persist, firing on 2 cylinders constantly
e. Quickly cycling the key on and off seems to alleviate the problem 80% of the time. Comes back a minute later, cycling the key again gets rid of it.
2. Spark Plugs
a. Testing old plugs, resistances 6000-9000, all good
b. Bought and tested new plugs
c. Installed new plugs
d. Reset MIL
e. No change
3. Plug Wires
a. Tested old wires, all under 7000/foot
b. Bought and tested new wires, spec’d ok
c. Installed new wires
d. Reset MIL
e. No change
4. Begin Factory Flowchart Diagnostic
5. DTC P0351, P0352, P0353: CHECK IGN START/RUN VOLTAGE TO COIL PACK
a. 11.52 volts, ok
6. JE5 CHECK FUNCTIONALITY OF SUSPECT COIL DRIVER (CD) CIRCUIT
a. Not done
7. JE6 CHECK SUSPECT CD CIRCUIT FOR OPEN IN HARNESS
a. Pin 26+58, both 3 ohms, ok
8. JE7 CHECK SUSPECT CD CIRCUIT FOR SHORT TO VPWR IN HARNESS
a. 0.01 Volts, ok
9. JE8 CHECK SUSPECT CD CIRCUIT FOR SHORT TO GROUND IN HARNESS
a. Not done
10. Replace Ignition Coil
a. Bought brand new ignition coil and replaced.
b. Reset MIL
c. Drove for 1 hour, symptoms returned, along with a P0351.
11. Begin additional diagnostics
12. Ignition Coil Harness
a. Purchased and installed brand new ignition coil connector (WPN-517)
b. Reset Mil
c. No change
13. Bypass harness
a. Cut wires to pins 26+58 appx 2” from ECU
b. Cut wires to ignition coil connector appx 4” from coil.
c. Ran 16ga. bypass wire to eliminate chance of intermittent fault in the harness.
d. Reset MIL
e. No change
14. Ensuring ignition coil ‘A’ was in fact dead
a. Swapped wires from pin 26 and 58.
b. Swapped plug wires from 1+4 and 2+3.
c. Reset MIL
d. New MIL, P0352, failure in ignition coil ‘B’.
e. The computer thought that ignition coil B was faulty, but it was actually hooked up to ignition coil A.
f. This meant that ignition coil ‘A’ was actually faulty.
g. Switched all wires back to original configuration.
15. Another Ignition Coil
a. In case some wiring fault fixed since step 10 had fried previous coils, another new coil was purchased and installed
b. Reset MIL
c. Drove for 1 hour, symptoms returned.
16. Reattached factory harness between PCM and ignition coil.

Thanks for reading. ANY suggestions, no matter how seemingly unrelated, would be useful.


superbeast04 is offline  
    Reply With Quote