xjarhead1999

some of the codes i got im a little worried about. some im not. what would i need to do for these? or which ones do i need to worry about. also i got codes during koeo that my book says only pertains to koer test. is something wrong or do i just ignore those?

koeo
31: canister or egr valve control system -
63: throttle position circuit - does that mean i need to adjust it or that it is bad and nees replaced?
66: no mass air flow sensor signal - im guessing that means its bad or something.
87: fuel pump circuit - this is one im really worried about. does this mean my pump is going bad or what?
91: o2 sensor problem - i knew i would get this one. i need to replace my harness.
96: fuel pump circuit - i guess it gets 2 codes?

koer
23: throttle position signal out of specified range -
91: o2 sensor problem - again i know this one.
33: canister or egr valve control system -
13: normal idle not within specified range - how do i adjust that?
74: brake on/off ground circuit fault - what is that?

roundman

all codes mean something that is not at factory specs or reading to the ECU what the expected signal range it was programmed to expect to see from the various sensors that send info to the ECU. sometimes this means the sensor has failed, sometimes it can be a bad electrical connection or a broken wire, sometimes it means something needs to be adjusted. the ECU will throw the code but it won't tell you exactly what is wrong, only that something related to the device mentioned in the code ain't right. it's up to you to test the sensor and it's wiring to find out what is bad.
that code 31 is most likely the EGR valve is not moving and sending a variable signal to the ECU. do you have the vacuum line unplugged?? is the valve dirty and stuck closed or open?? it's easy enough to pull the valve and check it and clean it with some carb cleaner. also make sure the electrical connection is plugged in to the top of the valve as this is what tells the ECU the valve has moved or not. code 63 and 23 are saying something ain't right with the TPS sensor on the throttle body. if it's working correctly, the output signal from it with key on, engine off should be a hair under 1.0 volts and it should increase to over 4.0 volts as the throttle is opened to WOT. this sensor is a variable resistor which can burn up, so check these signals with a digital volt meter and if the signal is not changing, then replace the TPS with a new one and set it properly.
66 is a big one, it means the MAF signal ain't there. check to make sure the connection is plugged in. could be the wire in the sensor got dirty and burned out also. not sure how to test this one but I think it can be done at an auto parts place.
not sure what the codes about the fuel pump are saying, could be the connections are loose somewhere between the ECU and the pump itself, not sure. there is a fuel pump relay in this circuit and in some models it is underneath the driver's seat. try unplugging it and plugging it back in to see if this helps any.
code 13 means the rpm signal seen by the ECU is too low/high. check the IAC on the side of the throttle body. sometimes they get dirty inside and can't move like they should to control the idle speed. they can be cleaned with carb cleaner also.
not sure what the 74 with the brakes is.
once you check or adjust any of these things, disconnect the negative battery cable for about 10 minutes to let the ECU clear the KAM (keep alive memory) and then reconnect it and see if the codes are cleared. if the code clears out, then you have corrected the problem with that sensor or circuit. if not, then take another whack at it! LOL

Tims 88GT

get you 02 sensors hook up right and run the scanner again, when somethings dont work right it will throw more codes then it should because a lot of the stuff on the 5.0 works togeather. that would be the first thing i do before i would start anything else, is their any diff between a mass air/sd harness for 02? if not and you need a new one i have on off my 88gt

xjarhead1999

i know im getting the o2 codes because of my harness. i won a harness off of ebay and if it would ever get here i plan on replacing it and the sensors. of course i won it about 2 weeks ago and it still isnt here. i do appreciate the offer for yours though tims

im thinking about getting the egr eliminator thing to trick the computer so mabey that would help that code.

i tried checking the tps like i thought it was supposed to be tested and i got .06 reading no matter what position the throttle is in. i picked up one and installed it and im getting .05-.22. i dont know what im doing wrong.

i checked the maf sensor and wireing and it looked good so i went to check about the electronics. i cannot buy just the sensor, i have to buy a whole new maf wich cost $70 with a $30 core charge. and considering i dont have an oem core id loose the $30. so guess ill have to find a junkyard or something.

the brakes one and fuel pump one are the ones im really worried about. ill look for the relay stated and give that a try.

the iac ill have to check out. i didnt even think about it.

i moved my battery to the trunk today so it was unhooked for awhile. i guess the codes should be erased and ill wait until i get my harness in before i check again.

thanks guys for the replies.

Trannyman

When you performed the KOER tests, did you "CODE 10-SNAP THROTTLE" ? Did the scanner ask you to press and release the brake and turn the steering 180 and release?

If you didn't do those during the KOER you will get false codes. The TPS code and the brake switch codes you got, could be spit out if you didn't do those things during KOER.

***EDIT***

BTW there are 3 places you get codes. KOEO, KOER, and Continuous Memory. KOEO and KOER codes are HARD codes, meaning they are happening RIGHT NOW! Continuous Memory Codes are stored codes meaning they have happened in the past but may not be happening now. For example, you will not get a VSS code in KOEO or KOER because it doesn't test the VSS during KOEO or KOER. A VSS code will only be found in Continuous Memory.

86HOGT

Take care of the KOEO codes first and the top ones since Ford pioritizes the codes for you.

black89gt

dont worry about the EGR code , that comes up on almost every ford. I know this becaus ei work at a tranny shop with my dad , BTW im only 16. All the rest you should either replace them or take them out and clean it.