[GTS 5.7]

Bought a code reader for my '95-it was a buck more than having somebody read them for me-and got--

556-fuel pump relay primary circuit failure
118-coolant temp sensor above max voltage

now what? I don't really know what these mean

[coolwaterblvd]

Sounds like a bad pump. The pump can still be running but just barely pop off the wires and check the resistance to see if it is within specs. The pump may be shorting out spiking the amperage draw on the car causing the weird readings. I had a similar problem on a 88 mustang it kept frying the fuel relay until I checked the pump and it was showing 0.00Ohms. even though it was kicking on, I replaced the Pump and fixed the problem. As a matter of fact I had just put the 94 alt on it that bumped up the amperage and started the problem because the old alternator did not put out enough just to fry the relay but still run the bad pump. Talk about a lot of trouble shooting to find this problem! But after the new pump install which is good idea anyway if you plan on more power in the future or a lot of miles, and try not to run under a quarter of a tank of gas or your pump life will be short. The fuel cap should also be change about every 3 yrs and get it from the dealer the autozone specials do not vent properly for a V8. I know I gave a little too much info but you can never have too much advice.

[GTS 5.7]

True,never too much info..the car runs good,that's why I'm confused about the fuel pump code,and don't have a clue on the temp sensor...CEL was on,and I've just done a lot to it,so thought I may have done something wrong...So you think the fuel pump is about to die on me?

[coolwaterblvd]

May be so, when was the last time you changed the fuel filter? If you have have around 80K or better is about the life on them if the filter has not been replaced about every 3 oil changes. And it can also put trash into the fuel rails as it goes out like a buddy of mine and ruin everything from the regulator to the injectors if you have never changed it.

[GTS 5.7]

Got 120K on it,had 104 when I bought it-far as I know it's the original.Something like that throw the relay circuit code?

[coolwaterblvd]

If it is fuel related code and electrical there is really only one component in the circuit, the the fuel pump.

[coolwaterblvd]

And the relay but if the relay was bad the oump would not work at all.

[meangreen92]

Regarding the Coolant Temperature Sensor code, was the engine fully warmed up when you scanned? Because if it wasn't, that'll cause it to throw a code.

[GTS 5.7]

Engine was warm,maybe not fully..Idled about 15 mins but was about 35-40 degrees out..Can find the codes listed (556=fuel circuit..etc)all over the web,just not what to look for(fuel circuit= check this)
I'll go for a drive,then pull them again---QUESTION,just dawned on me,the 556(fuel circuit code)showing in "stored" memory---that means it's probably OK,right? and the temp sensor is in "current" and "stored"..so maybe a new temp sensor will knock out the CEL?

[meangreen92]

I've gotten fuel pump circuit codes before, without noticing a problem. Is the light staying on? Or going on and off?

[GTS 5.7]

mine runs fine now too,and the light comes on 5-10 seconds after starting it and stays on

[meangreen92]

Pull the Key On Engine Running codes, it's gotta have some if the CEL is coming on.

[GTS 5.7]

Thought of doing that/and will when home next weekend,didn't cuz "the book" that came with the reader sid to get KOEO codes fixed/cleared before doing KOER test

PS--Meangreen,you're posting in another thread of mine,"the problem with doing it all at once.." please check latest and give opinion--and any others that have an opinion also--Thanx