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Ron
Ron, ASE Certified Technician
Category: Ford
Satisfied Customers: 34757
Experience:  23 years with Ford specializing in drivability and electrical and AC. Ford certs and ASE Certs
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2003 expy 5.4 p0351 code

Customer Question

2003 expy 5.4 p0351 code
Submitted: 1 year ago.
Category: Ford
Customer: replied 1 year ago.
Used a light on the coil connection. key on - Hot terminal burns bright. engine running - Pulsed side is pulsing. Same on fuel injector connection.
Expert:  Ron replied 1 year ago.

I'm sorry the Expert you requested was unavailable to assist you today. It appears that Tech is currently "Offline". Now that his 15 minute "request lock" has expired, hopefully I can be of some assistance in his place. Sorry for the delay.

The most common cause for the code P0351 to set is in most cases caused by a failing coil on the #1 cylinder, if you are you have injector pulse at the coil one quick way to check it is to swap the #2 coil with the number #1 coil and see if the misfire moves. If it does the you need to replace the coil. Check this for me and post back if you need more help and we can work from there if need be.

Customer: replied 1 year ago.
Sorry to post other tries:
Service engine soon light slowly blinking - engine rough
Initial code was 300 - random misfire
Then got code for misfire cylinder 4 - replaced coil on cylinder 4ran great - no code
2 days later, 351
replaced
cylinder 1 coil - 351
changed plug cylinder 1 -351
swapped coil from cylinder 2 to 1 - 351
Used a light on the coil connection. key on - Hot terminal burns bright. engine running - Pulsed side is pulsing. Same on fuel injector connection.
cleared code - "service engine soon" light off and when accelerated - service engine soon light on. - 351
Pulled plug cylinder 1 - looks fineHelp!!!
Customer: replied 1 year ago.
Swapping coils did not move the code to 352.
Expert:  Ron replied 1 year ago.

If your still setting the code P0351 and you are sure the ground switching signal from the PCM is okay then you are likely still looking at a failed coil and or the connection to it. If the coil checks okay then you have either a failing PCM or the wiring from it to the #1 coil, see the steps to retest it in the link below. Copy and paste the link to your browser to open the link..

https://dl.dropboxusercontent.com/u/104923897/P0351%20Oct%207.pdf

Customer: replied 1 year ago.
Resistence on coils are fine. Cannot find pin 26 on ecm.Also, A/C compressor will not kick on. all started at same time.
Expert:  Ron replied 1 year ago.

The pin 26 is a type , the driver signal for the number #1 coil is actually #35 see the connector view in the link below along with the pin location.

https://dl.dropboxusercontent.com/u/104923897/Pin%2035%20Oct%207.pdf

Customer: replied 1 year ago.
what do you mean by "The pin 26 is a type , "?
Expert:  Ron replied 1 year ago.

I meant the steps I sent you saying you need to check pin #26 was a typo, the driver signal from the PCM to coil #1 is actually #35 as shown in the connector view I sent you.

Expert:  Ron replied 1 year ago.

Take a look at the connector view at Pin #35.

Customer: replied 1 year ago.
I do not have a open circuit between the coil #1 red/light green and #35. Open between coil #1 light green/white and #35.Does any of this explain the A/C not working? Does the power draw shut down accessories?
Customer: replied 1 year ago.
I do have battery voltage on red/light green when key is on.
Expert:  Ron replied 1 year ago.

Yes the red /green is the power side of the coil circuit to all the coils, the pin #35 is the drive signal from the PCM, if you do not have an open circuit then you are likely dealing with a PCM problem providing the new coil is not defective. Im not sure an engine misfire would affect the AC performance unless the misfire is placing the computer into Limp mode which would shut the AC down.

Customer: replied 1 year ago.
If there is an open circuit between pin 35 and light green/white, does it make sense that when I pull the plug off the coil and using a light- I connected the green/white and the other lead to the positive side of the battery- the light flashes when the engine is running?
Expert:  Ron replied 1 year ago.

If you can only get it to flash with adding power then that would indicated the coil is not seeing power, dose it flash if you do not add power?

Customer: replied 1 year ago.
The light glows steady with key on and connected to red/green and other side grounded to battery.
If I am getting a flashing signal, why is the circuit showing open to the PCM?
Customer: replied 1 year ago.
I only tried to get it to flash with engine running. Is there another way?
Expert:  Ron replied 1 year ago.

No its only going to flash while craning and or running, the green/red send the key on power and the other wire is the ground switching signal from the PCM.

Customer: replied 1 year ago.
Does the ground switching flash from the PCM indicate I have a good circuit and a good PCM?
Expert:  Ron replied 1 year ago.

If you checking it with the coil connected by back probing the coil connector at the coil then yes, if that is the case, the coil should also fire if its okay.

Customer: replied 1 year ago.
Summary:
Could tests good
No open circuit
PCM sending signal
Still have p0351
What is next?
Customer: replied 1 year ago.
Sorry
Coil tests good
Expert:  Ron replied 1 year ago.

Like I said, in most case if the wiring to the coil from the PCM check okay and you have a good ignition source to the coil and a good coil then that leaves a failing computer. There is really nothing else that will set this code besides a bad coil and or the wiring or PCM.

Customer: replied 1 year ago.
If I put in a new computer, does it have to be flashed to my VIN? Do keys need to be reprogrammed?
Expert:  Ron replied 1 year ago.

Yes a replacement PCM will need to be flashed which will include key programming.

Customer: replied 1 year ago.
Any idea on the cost (out the door) of replacing the PCM?
Expert:  Ron replied 1 year ago.

You can get a reman unit after market for about $300 plus about one hour in labor for programming . For a dealer reman you can expect to pay more but for an exact price you are going to need to contact your local dealer for current pricing.