DIY KOEO/KOER/Cylinder Balance Self-Test Procedure

[Guest]

[Joel5.0]

DIY KOEO/KOER/Cylinder Balance Self-Test

NOTE:

For better resolution diagrams, open the attachments at the end of this article. You can zoom the picture once you open it in a pop-up window.

Definitions:

• KOEO = Key On Engine Off
• KOER = Key On Engine Running
• STO = Self-Test Output
• STI = Self-Test Input or trigger wire to initiate self-test routines
• CEL = Check Engine Light
• MIL = Malfunction Indicator Light = CEL
• ECM = Engine Control Module or computer
• DLC = Data Link Connector
• VIP = Vehicle Interface Port Connector = DLC
• SIGRTN = SIGnal ReTurN or ground reference for sensors provided through ECM
• EEC-IV = Electronic Engine Control IV generation or Ford's OBD-I system
• OD Codes = On Demand Codes, this are the failures the system logs based on a real-time check, failure is present.
• CM Codes = Continuous Memory Codes, this are the failure codes the system has logged and saved in memory based on a failure the system detected at one point in time.
• R Codes  = Engine Running Codes, this are the failure codes the system logs based on the KOER self-test routine.

Tools/Equipment:

• Analog VOM or 12-vdc Test Light
• Paper Clip or piece of Jumper Wire
• Pen and paper

Next...need to identify the VIP/DLC connector location. Using Ford Mustangs as reference, for '86-'93 models...it is located behind the LH/Driver side strut tower. For '94-'95 Mustangs, it is located behind the RH/Passenger side strut tower as shown below.

'86-'93 VIP/DLC Connector Location

'94-'95 VIP/DLC Connector Location

Now that the VIP/DLC connector has been found, check its terminals diagram........set the jumper wire, 12-vdc test light or AVOM as shown in the following diagram.

Codes flashing/needle sweeping patterns comes in two flavors, ’86-’93 Mustangs, pre-’91 Fords follow a 2-digit pattern….SN95 Mustangs and post-’91 Fords follow a 3-digit pattern as shown below:

2-Digit Codes

3-Digit Codes

Code 327

The following is a contribution made by Neomustangs, it's the results of a KOEO self-test using the CEL to read the flash patterns. If you watch, you'll see the following codes show up:

15 - 21 - 24 - 67 - 85 - 95 (OD codes first pass)
15 - 21 - 24 - 67 - 85 - 95 (OD codes second pass)

After those 2 sets, a 6 sec delay then 1 flash (= separator code 10) followed by another 6 second delay. Then......

95 (pause) 95 (First and Second pass of the registered CM codes)

<a href="http://www.youtube.com/v/vcYoApXdR2Y&amp;rel=1" target="_blank">http://www.youtube.com/v/vcYoApXdR2Y&amp;rel=1</a>

Codes Itemization:

• OD or "O" Codes:
  This codes are the first set of codes flashed during the KOEO self-test. They are the codes displayed previous to the "10" separator code.
• CM or "M":
  These codes are the ones flashed after the "10 Separator" during the KOEO self-test. These are codes the system logged during the previous 40 ignition cycles and were stored in memory.
• R Codes:
  These codes are flashed after the Engine ID code (2 = 4 Cyl., 3 = 6 Cyl. and 4 = 8 Cyl.) in the KOER self-test.

It is important the the codes get itemized to determine if they're "hard failures", intermittent or logged by operator error (operating the car with a sensor disconnected), since their definition may vary depending on the type of code. OK, let's run the self-tests.

Running a KOEO self-test:

1. Setup the VIP/DLC connector jumper as described above.
2. Turn Ignition On.
3. Count the flashing/needle-sweep pattern.
4. Write down the codes logged.
5. Start a topic with your problem in the Electronic Engine Management section.

Running a KOER self-test:

1. Setup the VIP/DLC connector jumper as described above.
2. Start the engine...make sure the gas pedal is not touched.
3. Watch for the Engine ID code to be flashed.
4. A this time the engine will increase idle speed, activate system actuators, check sensor inputs, idle will fluctuate, etc. The KOER routine usually takes 2-3 minutes to run, at the end of which the idle speed stabilizes and codes will start to flash.
5. Start counting the codes pattern.
6. Write down the codes logged.
7. Start a topic with your problem in the Electronic Engine Management section

Running a Cylinder Balance self-test:

The cylinder balance test checks that all cylinders are producing the same amount of power. To do so the system will turn off each cyl. injector, record rpm loss and compare it to the other cylinders. This test can be done three times in a row, each time it is repeated after the first one, the rpm difference value to ID a passing/failing cylinder will be lower (stricter).

If a cylinder is shown as weak in the third test (provided you run it a third time), it should be considered non-contributing. The tests may be repeated as often as needed if the throttle is depressed within two minutes of the last code output. Subsequent tests, after the 3rd. cycle, will use the percentage from the third test instead of selecting even lower values.

1. Run a KOER self-test as described above and wait until all codes are flashed, DO NOT TURN ENGINE OFF.
2. Within 2 minutes of the last code output, do a brief WOT.
3. Engine rpms should raise and the test initiated.
4. The elapse time of this test is 2-4 minutes after which time....the codes will be output.
5. Write down the codes logged. (90 = PASS, 10 = Cyl. #1 Fail, 20 = Cyl. #2 Fail.......)
6. If a code 90 (System Pass) was obtained, repeat 1-5 for a 2nd. run and goto 7.
7. Start a topic with your problem in the Electronic Engine Management section.

Check for the codes definitions/code type at http://sbftech.com/index.php/topic,849.0.html .

Clearing EEC-IV Codes:

1. Disconnect battery (-) terminal for 3-5 minutes.
2. The above will cause a code 15 (Keep Alive Memory (KAM) Test Failed) to be logged since power was removed from the system memory.
3. To clear this code (or any other codes) you could also use the alternate/quick procedure.

Alternate Procedure to Clear Codes:

1. Setup the system to run a KOEO self-test.
2. Turn Ignition On.
3. As soon as the codes start to flash, disconnect the STI jumper wire.
4. Turn Ignition Off, set the system to run a KOEO self-test again, and confirm code 15 is cleared from memory (CM codes).

This article was made with the contributions and material provided/available by/at:

• TENGRAM
• www.veryuseful.com
• www.fordfuelinjection.com
• www.my5oh.com
• Neomustangs

[Joel5.0]

Every now and then I read or hear customers saying..."there are no failure codes, since the CEL isn't turning on while driving, there shouldn't be any codes".......although that observation is true for most OBD-II systems, it's not TRUE for EEC-IV or Ford's OBD-I systems. This means that the possibility of having a failure code present causing driveability problems w/out having the CEL indicator at the instrument panel on, is not only true, but common. This is one of the reasons why the only reliable way to check EEC-IV systems is by running the system self-test routines described in the previous post.

....the following failures or codes are the only ones that would trigger the CEL/MIL to turn on for the time the failure condition is present, once the failure is not present, the CEL will turn off:

CIRCUIT		CODES
ACT		54, 64
ECT		51, 61
BP/MAP		22
MAF		26, 56, 66
TPS		23, 53, 63
EVP		31, 32, 34, 35
HEGO(1)		41, 91, 42, 92

⁽¹⁾ Based on a "lean-rich" switching counter timer function.

Intermittent codes will only trigger the CEL during the time the failure condition is present. Any other circuit failures may be present, affecting driveability and/or performance, but not cause the CEL to turn on....and can only be identified/retrieved via the self-test routines. Another case are the failures that are not logged in memory, but are present during engine operation.....any failure code that doesn't have a "M" = memory, continuous notation, but any of the others, falls under that category....as you can check at http://sbftech.com/index.php/topic,849.0.html .

What happens when the CEL is on?..... ....the EEC-IV uses a variant of a Failure Modes Effect Management (FMEM) strategy to compensate for the failures...or as described by Ford.....

The Failure Mode (FMEM) strategy protects vehicle function from adverse effects of an EEC component failure. The strategy recognizes open or short circuit failure for six sensors: MAF, TP, ECT, ACT EVP/EPT, and BP. In general, if the continuous Self-Test strategy recognizes a failure the FMEM strategy will execute an alternative vehicle strategy. The alternative strategy disables logic which relies on realistic sensor values. Some sensor FMEM strategies also substitute a "safe" value for the bad sensor.

What are those strategies?.....check the table below, look at the column of the failing sensor, and check the alternative actions it does....

Bottom line.....

Just because you don't see the CEL turning on, you may have circuit failures that affect EEC-IV functionality and performance, run the damn self-tests  ....it will provide you with the information you need to correct any problems w/out having to replace unnecessary components, and throw away hard earned .

[65ShelbyClone]

I am really glad somone put together such a comprehensive guide to doing non-OBD-II EEC diagnostics. I get tired of telling people they only need a jumper wire and $2 test light, NOT a $70 codescanner.