P1234 Error Code

[AlHensling]

It all started with a check gage light as the fuel gage went south.
Car running fine and then went flat as if out of gas.
Initially would not restart, waited 5 minutes and car restarted and check engine light now on and car in safe limp home mode no power over 4500 RPM.
OCB'd car and pulled a P1234 code which relates to fuel pump. Replaced the FP Relay as described in the forum.
Still receiving P1234 code.
Car has Ford Racing Tune with Pulley and Exhaust

 

[twobjshelbys]

Aren't there two fuel pump relays? I recall pulling two when I shut my car down for the flood.

It's interesting that a google search of "ford gt p1234" takes you to this topic:

http://www.fordgtforum.com/forums/showthread.php/20633-Cutting-off-at-4500-rpm-code-p1234

 

[AlHensling]

Replaced both relays.
Still same issue

 

[BlackICE]

If you have an SCT or similar data logger I would start by monitoring the fuel pump duty cycle and fuel rail pressure to see where the anomaly is. The fuel pressure should be close to 39 PSI +- less than 1 PSI unless the throttle is being move somewhat rapidly.

 

[nota4re]

The p1234 is set when the ECU cannot get duty cycle info from the fuel pump driver module. You replaced the FP relay (both of them?). They are across from each other in the Aux Relay Box. Did you also have a chance to check BOTH fuel pump fuses? (F3.1 and F3.2 - 15A each) Check those too. To be safe, when installing the Fuel Pump Relays I'd recommend to use electrical grease on the spades.

Too weird that the gauge failure and this occurring symptom occurring back to back. It would seem related.

 

[BlackICE]

http://www.fordforum.com/forum/general-tech-11/p1234-trouble-code-26533/

Since you had a gauge problem at the same time I would remove and reinstall your grounding strap from the battery to rule a bad ground out. I assume that your battery is in good condition and fully charged.

 

[twobjshelbys]

I've got to say this. I get it all the time. Everyone looks at the GT and wonders about maintenance and who I have work on it.. I tell them "Me. t's just a Ford. No rocket science". At the Cars and Coffee in Vegas last weekend a guy drove up in a new Lambo while I was talking (I didn't know the guy had a lambo) and I told him I changed my own oil - no $5K oil changes. And he said "that's low"..." I mean, come on, you can actually see the engine. I can't even find the plugs on my Dodge pickup, but the FGT? Everything is out there in front of God and everybody. So cool.

 

[Fubar]

If all that checks out, you may have a fuel pump gone bad. The pumps can be a little tricky to remove, I would not recomend the task for a shade tree mechanic (such as myself). You have lots of quality maintance shops available in your area.

What HP did your car get after the pulley, tune? And was it strickly a plug and play tune or did it get custom tweaks?

 

[AlHensling]

Kendall is going to check it out and let me know the issue.
Thank you all for comments.

 

[nota4re]

Happily the power & value of the forum strikes again! Al's problem was merely a fuse. I'm not concerned at all - as long as it doesn't happen again. (You gotta love OBD2-controlled cars. The Ford programming caught the fact that a fuel pump was not on-line and dutifully went into limp mode to protect itself.)

 

[AlHensling]

Well the saga continues. Engine light back on and car in limp mode again. reinstalled relays and cleared all fault codes but still in limp mode.
Kendall has a theory it has to do with low fuel so gonna try to verify fuel level as I have a dead fuel gage. Stay tuned for updates.

 

[Xcentric]

Did the fuse blow again? If so, there's a deeper problem.

 

[RALPHIE]

And who said that gauges aren't necessary....!

 

[nota4re]

And who said that gauges aren't necessary....!

Boy howdy!

Despite a non-functioning fuel gauge, the car is still illuminating the "check gauges" light (NOT the Check Engine light). My fingers are crossed that the ECU is still getting good fuel level data from the ultrasonic level in the fuel tank. Despite the gauge is not working, I think the ECU still knows the car is low on fuel. Sometimes the easiest solutions are the right ones. I'm hoping a fresh refill will solve this puzzle. If not, at least we've eliminated one cause!

 

[AlHensling]

Car was in need of fuel so it was topped off. Reset computer engine light went off for 15 seconds then back on. Error code P1238 relating to Secondary Pump Module. No blown fuses.

Any thoughts out there?

 

[bonehead]

What's left? As Fubar mentioned, fuel pump itself gone bad?

 

[STORMCAT]

I would remove and clean the primary ground. Check the fuses and change the relays again. They are cheap . I've had to change my secondary relay more than once. Next you can check the Fuel pump driver modules. There are two located in the front wheel well in the right side/ passenger side. I don't have the test procedure. Good Luck !!

 

[nota4re]

Well, this one is finally solved and with a car back in the hands of its happy owner. With the fuel gauge not functioning, the car was inadvertently run out fuel. This caused one of the fuel pump fuses to blow and it set the CEL and put the car in limp mode. With a new fuse in place, the car exhibited a different OBD2 code - but it was also still out of fuel. When the car was subsequently fueled, the P1238 code (and associated limp mode) persisted. Ryan picked up the car with our trailer for the ~75mi trek to Cool Tech so we could have a look. We initially went through all of the steps that Al did. Made sure all of the relays were good. Double checked all of the fuses. All good. We then turned to the fuel pump driver modules (behind the passenger side fender liner) - grrrrr. With access to the modules and the wiring, it was a fairly straightforward test to conclusively determine that the secondary fuel pump was deceased.

So, long story short is that Cool Tech will join the ranks to say that it is possible to replace a fuel pump through the access plate under the console on the inside of the car. It is no easy task as others will attest to. Lots of patience and experience with complex Chinese brain twister puzzles is a plus. Thank God for Ryan. No problem. Bad fuel pump was replaced (by the way, I think we took the last one in Ford's US inventory - so I hope there are more soon.), and the code reset and the car driven home.

Lesson learned: Don't run the car out of fuel. Also, the "Check Gauges" light which also serves in the GT as the low fuel light, still functions even when the fuel gauge is broken.

 

[AlHensling]

Thanks

Thanks to Kendall and Ryan for job well done.

Also Thanks to Rich at GT Guys for great advice and tips to diagnose.

The Forum is invaluable!