Ok, I pulled the codes, but what the heck do they mean
 

Ok I pulled the codes on my car using the KOEO and the KOER, but I'm not sure what all the code mean. Could someone please shed some more light on this for me.

521 (R) Wheel not turned during test or PSP problem. I assume that mean I didn't turn the steering wheel during the test

172 (R,M) Oxygen sensor not switching - system is or was lean - Single, Right or Rear HO2S -. I guess this means I have a bad O2 sensor

536 (O,R,M) Brake On Off open or shorted to ground -. I have no clue what this means.


186 (M) Injector pulse width longer than expected or Mass Air Flow (MAF) lower than expected - I'm not sure about this one either

anyone???

Hey I check the codes of some of my friends cars, but I thought the 87-93 stangs had 2 digit codes. What's up with that?

I never thought Fox body Stangs had 3 digit codes either.

1991 and up had 3 digit codes

To my knowledge, the codes should only be two digit for stangs. I recently used a code scanner on my 91, and got two digit codes. Maybe you are reading the codes wrong. Just in case you are let me recap how to do it. Once you start the test, pay no attention to the brief rapid blinks, if that happens. After a brief pause the codes will start. The two digit code should flash. After the code, there willl be a brief pause, then if there is another code it will flash, and so on. This group is given twice. Then there will be a long pause followed by one flash, and another long pause. This is the seperation pause. After the seperation pause comes the older codes that happened in the past. The EEC keeps a continuous memory. These will also be given twice. If you get a code of 11 then there are not any problems. Hope this helps you. It was frustrating for me the first time also, but definately helped me find my problem.

I suggest you buy a book with this information in it, which is readily available anywhere. Like the Ford fuel injection book for example. I could spend 30 minutes looking all this up and explaining it all to you, but why should I , when you can buy the book for $30.00

Maybe PKWUD will do it, he loves this stuff. Send him a private message. On second thought, maybe he is getting tired of doing everybodys dirty work or else he would have answered already.

Ill give you what I can from memory though. Brake on/off means just what it says. There is a signal wire from the brake switch that tells the computer if your brakes are on or off. Apparantly yours is fubar.

Was the engine warmed up before the tests?

Yes it was warmed up.

The first time I did it I thought I was only 2 digit codes, but when I tried to write them down like that it didn't make sense. They appear to be 3 digit codes. I didn't think fox bodies had 3 digit code until I looked at this site. http://ratnin.home.mindspring.com/eec_test.htm


this is where I found the part about the 3 digit codes http://www.promustangs.com/test3.html

I think the are 3 digit codes, although I very well could be wrong. This was my first time doing this and I could have misread it. I'll do it again later.

Which tests did the codes appear in, specifically?

The 172 code and the 186 code poped up durning the KOEO test and the 536 and 521 code poped up on the KOER test.

That's being a little harsh don't ya think? People come here for help. Not because they are lazy tight @ss bastards that don't care to do their own work. The guy obviously is trying to tackle this job himself and needs a little expert advice. Books can be a little overwhelming to the novice and are never a cure all for problems you may encounter when attempting something like this for the first time. Most are merely for reference, but if you don't have a clue what to look for it's hard to find the information you need. The best help you can get is from someone who has done it before. Books don't answer your questions when you get confused.

Okay, the KOER codes you got are because at a certain point during the test, you are supposed to turn the steering wheel, and at another point, depress the brake pedal. Without a scan tool, you won't know when to to those, so don't worry about them. The codes you got during KOEO didn't reappear during KOER, so they aren't current codes. You need to disconnect the battery at the negative cable, turn on the headlights for 15 seconds to drain any capacitors, and hook the battery back up and run both KOEO and KOER tests again. What drivability symptoms are you experiencing?

I've got a miss at idle and the rpms don't don't stay steady at idle they go up and down 200-300 rpm.

The codes I pulled were from the memory

Mach 1 I've looked up the codes in a manual and they only say what was in my original post. It didn't tell me what was wrong. Like the brake on/off switch, I had no clue what that was. And the other codes I wanted to know how to test the parts to see if they were bad or not.

Maybe I did come across harsh, but I just think that asking a blanket question such as what do several codes mean is rather useless.

I could tell you what the codes mean, then what? Then you need help troubleshooting all of them, and then you run into real technical problems, and it is at this point I think the question shoud be asked.

Maybe one code or question, but when you need a lot of information, I feel it is best to try to narrow it down on your own (after all, if you didnt enjoy working on cars, you wouldnt he here, and troubleshooting problems is where the real satisfaction that many people experience working on their own cars comes into play) and then if you are still stuck, ask questions.

But this is just my opinion, if someone is willing and/or available and able to walk you throught the entire procedure, thats fine also.

Tireburner-
I still need you to reset the ECM like I described above, and retest both KOEO and KOER. What I'm looking for is to see whether or not any codes come up that are new while the problems are occuring. If you reset the ECM, and upon retesting don't set any codes, yet the idle miss is still there, than the previous codes aren't the cause.

Something else you can try the next time the idle miss happens is to unplug the IAC connector (provided the engine is warmed up) and see if the problem changes.

Take care,
-Chris

...And, don't worry about codes 521 or 536.

PKRWUD the only code I pulled was, 512 (M) Memory power (PCM pin 1) was interrupted - Was battery disconnected ?, and that's because I unhooked my battery.

The check engine light come on and off so I'll have to check it the next time it comes on.

P.S. thanks man, you've been a huge help.:)

Mach 1 I understang why you could be irratated. I came here asking a large blanket question. But I didn't know what to do next. I was really just looking for a link to a page that told me what to do.

Keep me posted.

Take care,
-Chris