fuel pump relay

[thecrew2999]

ok where is the fuel pump relay located? i keep throwing a code saying about the fuel pump relay which is 543 code.
thanks for any help

 

[shopartsnw]

It is in the black box under the radiator cover. If you are an MTX, it will either have a large M on it (89-93) or a large D on it (94-95).

Also, make sure the inertia switch is not tripped in the drivers rear fender (inside the trunk). A bad fuel pump can also throw this code.

- Mike

 

[SHOZ123]

It's in the CCRM. If it is the low speed fuel pump relay don't worry about it as you don't have one.

 

[thecrew2999]

It's in the CCRM. If it is the low speed fuel pump relay don't worry about it as you don't have one.

low speed? a stock you mean? i had a walbro in there but i put a stock mtx one in there now because i thought it was bad.

 

[SHOZ123]

No, I think the early Gen 1s had a two speed pump. The DTCs associated with it were left in the PCM, at least in my '93 aynways as I use to get low speed fuel pump codes.

 

[thecrew2999]

ok i changed that box by the radiator and it had a J or something on it.. its for atx and its a 93, well anyways i put the one off the donor car on that was a 92 mtx and it was rusted bad and all but the contacts were looking ok yet... well anyways i hooked it up and the fuel pump didnt kick on at all... im guessing mtx and atx ones are different.

EDIT: also the box on my car already is cracked where the plug goes in like i mean the connector part has a crack going down where the prongs going into the box... not the plug but the connector on the box.

also i checked the switch in the back of the trunk and i dont know it dont feel like i can push it in at all... is it suposed to move up and down or soemthing because i tried a few times and nothing happened like no movement in the button itself.

 

[TYSHO]

Bypass the inertia switch in the trunk, or at least test the connector and see if power is running to it when someone turns the key to the on position. You need someone back there looking, because after 2 seonds and without the engine turning, the relay will kick back off.

Do you hear anything clicking in the engine bay when you put the key in the on position? If not, it's an idication that the IRCM is not receiving power. Run the ECC port test and see if it kicks the relay on.

 

[1993MTXSHO]

matt if we ever get together to do my trans or w/e I have one of those relay boxes from my 94 atx with the J on it. You can see if that fixes you problem

 

[thecrew2999]

Bypass the inertia switch in the trunk, or at least test the connector and see if power is running to it when someone turns the key to the on position. You need someone back there looking, because after 2 seonds and without the engine turning, the relay will kick back off.

Do you hear anything clicking in the engine bay when you put the key in the on position? If not, it's an idication that the IRCM is not receiving power. Run the ECC port test and see if it kicks the relay on.

i dont know if i mentioned but the car does run but it keeps idling up and down real hard then stalls itself... i keep getting the code 543 for the fuel relay as im starting to figure out

heres code 543



543 (O) Fuel pump monitor circuit shows no power - Power / Fuel Pump Circuits
(M) (Service 556 code first if present) Fuel pump relay or battery power feed was open - Power / Fuel Pump Circuits

 

[thecrew2999]

matt if we ever get together to do my trans or w/e I have one of those relay boxes from my 94 atx with the J on it. You can see if that fixes you problem

ill probley have to take you up on that offer because i dont think (the first SHO i ever seen in a junkyard) haha... anyways i dont think that car has one on it since it was in a front end crash

 

[TYSHO]

i dont know if i mentioned but the car does run but it keeps idling up and down real hard then stalls itself... i keep getting the code 543 for the fuel relay as im starting to figure out

You're over paranoid. That code appears when you stall the engine. Move on to fixing your idle problem. Try resetting the idle.

 

[thecrew2999]

no cuz i keep resetting the code and its still there even if the car dont stall


and no thats not the code for stalling the car its

556 (O,M) Fuel pump relay primary circuit fault - Power / Fuel Pump Circuits

 

[thecrew2999]

also what do you mean resetting the idle ?

 

[TYSHO]

no cuz i keep resetting the code and its still there even if the car dont stall


and no thats not the code for stalling the car its

556 (O,M) Fuel pump relay primary circuit fault - Power / Fuel Pump Circuits

I will glady go outside, stall my car, and pull the codes all in front of the camera and show you that it will pull up code 543. BTDT and have 6 SHO's that say so.

You need to properly reset the codes if you want to clear them from the memory. Look that up and how to reset the idle in a search. These have been discussed many times in the past. If you don't reset the idle, it's not going to keep a steady idle when you turn accessories on like the a/c, and can stall out when turned on.

 

[thecrew2999]

thanks and im sorry i must be mistaken but i was told that before about the code..


its worth a shot because i mean it dont idle for a damn and when i hit the gas im starting to think the car laughs at me and then dies

 

[TYSHO]

its worth a shot because i mean it dont idle for a damn and when i hit the gas im starting to think the car laughs at me and then dies

Well, when did this start? Did it start after removing the battery cable to do some work on the SHO, or just a problem that became worse?

If from previous work and removing the battery cable, most likely the idle reset. If not, and just something that came along and became worse, start looking for vacuum leaks in the intake. It can possibly be a combination of both, as well.

 

[SHOZ123]

With the key on and a ground wire, ground wire the connector in the fuel pump slot. This will force the fuel pump on continuously for testing.

 

[thecrew2999]

the problem came after me swapping the atx to mtx and its been there since then and ive had problems along the way so it took me awhile till i got free time and spare money to get things working again..

but ever since i swapped everything its been running like this i had the engine out and the tb is different now heads are 3.0 on my 3.2 block all kinds of stuff happened so im gonna try the idle resetting which as im told you disconnect the battery and reconnect it after like 5 mins and let it idle on its own for 5 mins without touching anything

 

[TYSHO]

He mentioned a couple post up that the car does run, it's a jumpy idle that's the problem.

With the key on and a ground wire, ground wire the connector in the fuel pump slot. This will force the fuel pump on continuously for testing.

 

[thecrew2999]

i tried resetting the idle and it idles on its own but its kinda bumpy like real slight, but when you hit the gas it bogs way down and back up and when its warmed up it bogs up and down when you hit the gas then dies almost everytime..

if you dont touch the gas it sits there idle almost perfect but the exhaust smells of unburt gas bad not to mention it backfires a little every so often...

im gonna get new o2 sensors and and change the plugs and wires and run so injector cleaner in there also and im gonna change the coil pack with the spare i got from the 92 mtx donor car i had.

if that stuff dont work im gonna check compression fuel pressure and change injectors and check all the vacuums, i checked some tonight and they seemed to be no leak actually when i took some off it seemed to wanna run good like it should almost so i mean i got a lot more to check but damnit im gonna get this working or im just gonna get mad at get another SHO and this will be the ugly sister car.