2004 Mustang GT – Fuel Pump Not Priming

[Fayio]

Hey everyone, I’m chasing a fuel issue on my 2004 Mustang GT and could use some guidance.

What happened:
My front driver side turn signal pigtail broke off and left the 3 pins exposed and got extremely hot. Right after that happened, my fuel pump stopped priming and the car died.

Fuel pump does not consistently prime

• Car will start sometimes and run for a few minutes, then shut off
• Occasionally restarts, but bogs badly when giving it gas and dies again
• Fuel pump sounds weaker than it used to

What I’ve replaced / checked:

• Replaced fuel pump twice
• Checked fuel pump fuse (good)
• Checked inertia switch (not tripped)
• Checked voltage at fuel pump connector:
  
  • ~12V present
  • Also seeing some ~5V signals on other wires

What I’m thinking:
Since the issue started immediately after the wiring short, I’m suspecting an electrical problem rather than the pump itself. Possibly:

• CCRM damage?

What should I be testing next to narrow this down?
Is there a specific circuit, ground location, or known failure point I should check after a short like this?

Now the car just cranks doesn’t even start

I’ll Appreciate any help.

 

[LILCBRA]

Welcome to the site! First question that most will pose: have you pulled any codes?

 

[Fayio]

Thank you bro,Yeah I just scanned it and I’m getting P1235 (fuel pump control out of range) and P0190 .Do these usually point toward CCRM or wiring on these Mustangs?

 

[Noobz347]

I think you are likely correct about the CCRM. I've seen a bunch of these come up lately.

Do you have a good wiring diagram for your car? Of so, run a temp jump wire to bypass the CCRM and that should give you your answer.

After that... Should you discover that the CCRM is at fault, you have couple of choices:

Try and replace the CCRM with whatever you can find online etc...

Use the current CCRM as a trigger for a new relay, bypassing the bad CCRM Internal Fuel Pump Relay.

 

[Fayio]

I don’t have a wiring diagram for my car
If you have one or know which pin I should jump for the fuel pump test, that would be helpful thank you

 

[Noobz347]

I do not possess a diagram for your year car but check this out:

2004 Ford Mustang GT Complete Color Electrical Wiring Diagram Manual on USB | eBay

These wiring diagrams coverAll engines andTrim levels. Sound Systems. Shift Interlock. Power Windows. Power Distribution. Interior Lights.

www.ebay.com

 

[n0v8or]

I noticed one item not mentioned in your "replaced/checked" list: the fuel pump driver module. This electrical module receives signals from the engine/powertrain control module (ECM/PCM), and cycles the fuel pump on and off to maintain fuel pressure at the level requested by the PCM. This video shows the module location and how to access it:

View: https://www.youtube.com/watch?v=aum_KVbX910


You can view the fuel pump circuit diagram here (see next post for link).

 

[n0v8or]

HTML version of the circuit diagram does not display properly on my omputer. I converted it to JPG and posted here:

Dropbox

www.dropbox.com