35th Anniversary Thunderbird Registry

EEC Self Test

Here is one procedure you can use to pull the codes from your EEC without having to purchase or use a diagnostic tester or code checker. I hope it is helpful.

Here is where the EEC, and the ARC/EVO connectors, are located on a 35th. They are clipped to the back of the passenger side shock tower. The EEC connector is marked "EEC TEST".   To remove the connector from the shock tower, grasp it at the bottom and pull up. It is held in place on a plastic holder. It should pop up with a good easy pressure.

Here is the connector and single lead with the cap removed.   Connect a test light probe as shown above and position the probe so you can see the light blink when you test.
Get a pencil and a pad ready to jot down the codes.    
Now just perform the Key On Engine Off and Key On Engine Running tests and you're ready to record the codes. You can either use the test light or your Check Engine light to record the flashes.
To perform the KOEO (key on engine off) test:
Make sure the engine is at normal operating temperature.
Connect the tester or voltmeter as outlined and get your pad and pencil ready.
(Be sure you don't let the connections come loose during these tests or you may lose some of your codes.)
Turn the ignition key on but do not start the engine. The EEC will perform the test.
The codes will be displayed by the flashes in sequence. For example: A code 26 is two flashes, a pause, then six flashes.
The codes will follow each other by a longer pause of about 4 seconds. The codes will follow in numerical order and will repeat the series one more time. After that series of codes is completed, any continuous memory codes will be displayed.
Now you are ready for the test with the engine running.

KOER(key on engine running) test:
Start the engine and let it idle. The engine idle will increase indicating the testing of the ignition advance to see if it's working. When the idle returns to normal, shut off the engine, wait a second or two, then restart it and let it run for about 2 minutes. Shut the engine off, wait about 10 seconds, and then restart and be ready to record your codes. There will be 3 quick flashes and then an engine code. Then another pause and one flash. This one flash tells you that you need to tap the accelerator pedal to test the throttle operation. Then there will be a pause and then the KOER codes will flash. Each code will flash with a 4 second pause in between. These codes will repeat one more time and then quit. You now have the engine running codes.

Click Here for the list of EEC codes if you need them.

For an actual code scanner, I just recommend the SunPro Ford scanner like this one.
I keep one of these in the trunk of my 35th. You can find them at Autozone and other automotive outlets. I can use it for the EEC, ABS, and EVO systems since they all use the same connector.

I hope you find this information helpful.


Disclaimer: This article is for personal use only and for assisting owners in maintaining their vehicle. No publishing or reprinting is allowed unless by permission by the author of this article. The author is not responsible for any damage that occurs from the use of this information.