code 543

[SvtBlack95]

alright i picked up a code using my snapon scanner and it said code 543- O,C Fuel Pump circuit open; Battery to PCM ........do i need a new fuel pump???

 

[TxCobrA98]

umm iono what that stuff means but when you turn your car on to the accessory mode or w/e it is.. the one before you actually start the car, do you hear the whine noise from the fuel pump?

 

[SvtBlack95]

ya i hear the fuel pump its working i just dont understand the code and how to fix it cuz its making my car runn like poop..... if i hit WOT then it snaps out of it and its back to normal.... i slow down and its back to stuttering again

 

[Downshift]

How new is that 255? Or is it not in yet?
Something definetly sounds fishy though man, you said when you WOT its fine but otherwise no.... Did you just get it tuned?

 

[SvtBlack95]

i didnt put the new 255 hp fuel pump in its still the old one .....i mean if its a bad fuel pump then that sno problem i have one sitting right here but Fuel Pump circuit open; Battery to PCM seems wierd to me

 

[94Vert]

Do you know what the pcm is?

 

[SvtBlack95]

powertrain control module i think?

 

[94Vert]

I wouldn't put all my money on the fuel pump, but since you have one I would change it and see if it solves it.

 

[ripper]

You have that blower on there with just a stock fuel pump?

 

[SvtBlack95]

ya i have a stock fuel with the t rex inline ran awesome never leaned out on the dyno ...... i bought a 255 hp thats goin in it soon just wasting some more gas so i wont have to siphon alot of fuel alot...... but it shouldnt give me a code right unless the fuel pump it self is lefting go

 

[SvtBlack95]

codes 172 o2 sensor lean bank 1 and 332 egr valve not opening also came it does anyone think those may have caused this??

 

[ripper]

Lean means your fuel pump is going or cant keep up with fuel demand. Ive got a 96 so im sure what the codes mean though.

 

[SvtBlack95]

i just bought an o2 sensor ill putt it on tommorrow and see how she runs

 

[Hybridbird]

The PCM is keeping your fuel pump circuit open all the time,its not getting enough/intermittent power.You don't have this problem under WOT because your PCM goes into closed loop mode and doesn't take and input from any sensors,it just maxes out on everything.

 

[ripper]

There ya go i knew someone would know what the hell was goin on. I asked my mech and he said the exact thing hybrid.

 

[SvtBlack95]

ok now that i know whats goin on how do i fix this problem???

 

[SvtBlack95]

anyone??????

 

[94Vert]

Try changing the o2 sensor. I would change the pump anyway though. Your making high hp and the stock pump is only gonna last so long.

 

[SvtBlack95]

ya im gonna start today on the pump and o2 sensor ...... now i have a stock fuel regulator will it effect the way the new pump flows ?? i know i need to get one its just i dnt have cash right now

 

[94Vert]

I would think the stock preasure would be ok. Especially since your new pump can push 255 lph out.