Notes on pulling EEC-IV codes | Ford Explorer Forums - Serious Explorations

  • Register Today It's free!

Notes on pulling EEC-IV codes

MrShorty

Explorer Addict
Joined
December 27, 2001
Messages
5,078
Reaction score
20
City, State
Spanish Fork, UT
Year, Model & Trim Level
92 XLT and '87 Bronco II
This is from a post I wrote in October. Intended as a supplement to other sources. There are several others on the net (put "Ford EEC-IV self-test" into your favorite search engine), and any good repair manual should have instructions. FWIW, the first time I did it, I was working from my Haynes manual and managed to figure it all out.

I hope this proves helpful

I see from another post that you didn't like www.fordfuelinjection.com's site. Here's a quick run down:

Test 1: Key On Engine Off (KOEO) test:

1) Preheat engine. Turn the key off and set up as per www.troublecodes.net/Ford. Your choice if you want to use a voltmeter, a testlight, or the CEL (aka MIL) as the output device. Test procedure is the same in all cases, it's just a matter of output device.
2) Turn key on. Relays will click, fuel pump will run briefly as the computer checks various parts of the system for errors (This will be the source of the KOEO codes to be explained shortly).
3) Fast codes are output. I've seen a couple of different descriptions of what information is contained herein. In any case, all you may see is a brief movement of the needle/weak flash of the light to indicate the fast codes have been output.
4) KOEO codes are output. These are codes set during the aforementioned KOEO test. KOEO codes are output, then repeated. Note that if no faults are detected, the computer will output a 111 system pass code. I've seen several attempts to describe code output format, all of which seemed more confusing until you actually try it. My best advice is to try it and see what happens.
5) After the last KOEO code is output the second time, there's about a 6 second pause, a single pulse/flash (the separator pulse) and another 6 second pause. Then the continuous memory (CM) codes are output. CM codes follow the same format as the KOEO codes, and are repeated twice. CM codes are codes set during normal engine operation (often associated with a lit check engine light) and stored for retrieval.
6) Turn key off and disconnect to complete test.
7) If you want to clear CM codes without clearing Keep Alive Memory (KAM), repeat test, disconnecting the STI-SIG RET jumper wire anytime during KOEO/CM code output.
8) If you leave the key on and test connected after last CM code is output, you can enter a test mode called output state test mode. Press the throttle to enter output state test. In this test mode, each press of the throtlle will trigger the computer to cycle various solenoids/controls (transmission solenoids, EGR regulator solenoids, etc.). This mode can be used to test these components.

test 2: Key On Engine Running (KOER) test.

1) Preheat engine. Setup same as for KOEO test.
2) Start engine.
3) Engine id is output. This is a code to indicate the number of cylinders the computer is set up for, and is half the number of cylinders. So you should get three flashes/pulses for a 6 cylinder engine (2 for a 4 cylinder, 4 for 8 cylinders).
4) Immediately after engine ID is output, press brake so computer can test BOO switch. (FYI, other applications have a power steering pressure switch that is tested at the same time by turning the steering wheel. Not necessary on Explorers).
5) Engine will go through a low speed and then a high speed test. These tests will take up to a couple of minutes. During this time, if you want, you can test timing advance with a timing light. Computer will advance timing a fixed 20+Base BTDC. Base is almost always 10 BTDC, so you should see about 30 BTDC timing.
6) At end of KOER test, as engine spins down, you will get a pulse/flash for the dynamic response test (DRT test, aka "goose" test). Perform a brief wide open throttle.
7) KOER codes are output.
8) Turn engine off and disconnect to end test.
9) On sequential fuel injected models, the computer can perform a cylinder balance test. After step (7), press the throttle to enter the cylinder balance test. During this test, the computer will disable each fuel injector one at a time while monitoring idle speed. Any cylinder that doesn't effect the idle speed will be indicated by a code at the end of the test. (Disclaimer: I don't have SEFI, so I've never tried this test. I don't know how well it works.)

Is that easier to follow?
 



Join the Elite Explorers for $20 each year.
Elite Explorer members see no advertisements, no banner ads, no double underlined links,.
Add an avatar, upload photo attachments, and more!
.





cool post - thanks for sharing! :thumbsup:

-Drew
 






Mr. Shorty is one of the best of the best on this board. For newbies, when he weighs in on an issue, especially electrical diagnosis, you just heard from the ultimate authority.
 






Feel like I need to add a little something here. Call it "how to get/communicate the most information possible from my EEC-IV codes."

I often see someone post a request like, "I pulled codes and got x... HELP!" My first question in response to such a post is usually, "Is x.. a KOEO, KOER, or CM code?" 2nd question: "Did you get pass (11, 111) from the other portions of the test?"

In my experience, the designations "KOEO, CM, KOER" to identify a code add a significant amount of information to most codes. I would suggest that, when pulling or conveying codes, always include some designation. Another suggestion would be to include which portions come back "pass" (11/111 depending on year/engine). Doing so conveys more information than just "I got code x.."

Example:

Instead of "code 158"
note
KOEO: 111
KOER: 111
CM: 158
 






Another note. Sometimes someone will post something to the effect of, "there were no codes in the computer." no codes can be interpreted two ways:
1) The computer didn't respond at all to the self-test trigger or
2) All tests came back "pass" (11/111)

If the EEC-IV computer doesn't have any errors/faults to report, you will get pass codes from all three portions of the test, and it is best to report it as such. So, instead of, " no codes in the computer" report the condition as, "all pass codes from the computer."
If you pull codes from the computer and the computer doesn't seem to respond, then it's time to investigate why the computer didn't respond (operator error, bad connection between computer and self-test connector, no power/ground to the computer, etc.).
 






http://www.explorerforum.com/forums/showthread.php?t=231222

Somebody posted this thread with a video of his check engine light flashing the codes. For those who want to see what the test looks like, this might be useful to see what the flashes look like, and see if you can come up with the same codes we got.
 






...Great idea MrShorty...:bigthump

...Here is another video in post #16 of this thread...This time he is using a scan tool to read the flashes...This thread is great for first timers to see that he did miss waiting for the end of test codes ...;)

http://www.explorerforum.com/forums/showthread.php?t=232262
 












Extra Wire?

Hello,

I began the process today of reading the OBD1 codes on my 93 Explorer. This thread will be very helpful. I found the large black connector OK and the separate small connector. However, the small one has TWO wires running into it --- a green one and a gray/red one. Which one do I connect the jumper to?


Also one (white) of the many wires that run into the black connector can be pulled out. This single wire terminates in a connector itself. When viewing the face of the black connector, this white wire is housed on the far left. Could this be the correct one to connect the shorting wire?

Would appreciate your reply.

Thanks
 






However, the small one has TWO wires running into it --- a green one and a gray/red one.
My wiring diagram for my '92 shows that the gray/red is Vref which feeds +5V power to several sensors, and the dark green wire is the return wire for the octane adjust pin. That connector is over in the same area, so I think what you are seeing here is the connector for the octane adjust pin.

This single wire terminates in a connector itself. When viewing the face of the black connector, this white wire is housed on the far left.
On my '92, the STI connector does connect to a white wire, but that wire goes into the harness -- not to the self-test connector.
 






Thanks for the reply. I guess I'm still confused here. Self-Test??? I've taken a clear pik but I'm not allowed to attach it, and I don't have a way to upload it to the web. Would you be kind enough to give me aa email address so I can send this to you?

By the way, The white wire has a purple stripe as well.

Many Thanks
 






The white/purple wire should be the STI lead, which you should jumper to SIG RET to enter self-test mode. The picture at troublecodes.net/Ford I referenced above is pretty good.
 






MrShorty, I ran the KOEO test today and got codes 157 and 341. I will clean the MAF and hopefully get fixed up. I need to know if the Octane adjust service pin (Code 341) needs to be connected to somthing, Mine just hangs loose but I wanted to check this out. I also want to know if I need to run KOER tests if the MAF cleaning fixes things.

Many Thanks
 






Most of the time there's a shorting bar in the octane adjust service pin plug that allows the timing to advance 3 degrees more than without. If the engine pings excessively with this installed, it often gets removed to alleviate the pinging. If the engine is running fine, the shorting bar is not really needed.

If cleaning the MAF resolves the CM 157 (my code list indicates that the 157 cannot be a KOEO code), then you don't need to run the KOER test. If I were in your position, I'd probably run the KOER test anyway, if only for the practice.
 






so my 92 xlt wont have the SEFI either correct?
 


















This is from a post I wrote in October. Intended as a supplement to other sources. There are several others on the net (put "Ford EEC-IV self-test" into your favorite search engine), and any good repair manual should have instructions. FWIW, the first time I did it, I was working from my Haynes manual and managed to figure it all out.

I hope this proves helpful
Mr. Shorty I hope your still working these forums... I need help (don't we all) I have a 95 ford explorer XLT running jerkish. The CEL is on and I can't get a code reader to pull the codes? After seeing Mr. Joe dirts info I manually pulled the following codes, not sure what to do after this? I hope you can help. Thanks
KOEO 335, 335
CM 172, 332, 336
KOER 412, 121, 326, 411, 167, 632
 






Start with the KOEO 335, which is (almost) always the DPFE sensor.
 



Join the Elite Explorers for $20 each year.
Elite Explorer members see no advertisements, no banner ads, no double underlined links,.
Add an avatar, upload photo attachments, and more!
.





Start with the KOEO 335, which is (almost) always the DPFE sensor.
Thanks for the speedy reply! I'm not a mechanic by trade but I am very mechanically inclined... I'll look into the Differential Pressure Feedback EGR Sensor and let you know. Many thanks!
 






Back
Top