Having an engine code of 998 means that the KOEO (key on, engine off) test was not completed. If everything is fine during this test, you should get a code 11. You will get the codes twice, and then there will be a pause of between six and nine seconds between them. A separator pulse will signify the end of the KOEO codes, and then there will be another pause of the same duration.
To perform an EEC-IV KOEO test, make sure that the reader is disconnected from the diagnostic port and run the engine until is at normal operating temperature. Turn the engine off, wait 10 seconds and connect the reader. Turn the ignition on one click, but do not start the engine, and do not push the throttle.
A few clicks and whirrs are normal as the solenoids activate, and then the reader will flash as the codes are output. You can ignore this flash because they are factory codes that will be unintelligible to the reader. If all is well, you will receive a code 11; if not, make a note of the errors.
After a few seconds, the reader will start to get Continuous Memory Codes; if there are none, you will get a code 11. If there are Continuous Memory Codes present, the reader will display the codes for them twice. Make a note of these numbers.
When you have all the codes, turn the reader off. You will need to check out the codes and make sure that they are corrected before you run a KOER (Key On Engine Running) test.
To get rid of the Continuous Memory Codes, deactivate the reader while the codes are being output during the KOEO test.
To perform an EEC-IV KOEO test, make sure that the reader is disconnected from the diagnostic port and run the engine until is at normal operating temperature. Turn the engine off, wait 10 seconds and connect the reader. Turn the ignition on one click, but do not start the engine, and do not push the throttle.
A few clicks and whirrs are normal as the solenoids activate, and then the reader will flash as the codes are output. You can ignore this flash because they are factory codes that will be unintelligible to the reader. If all is well, you will receive a code 11; if not, make a note of the errors.
After a few seconds, the reader will start to get Continuous Memory Codes; if there are none, you will get a code 11. If there are Continuous Memory Codes present, the reader will display the codes for them twice. Make a note of these numbers.
When you have all the codes, turn the reader off. You will need to check out the codes and make sure that they are corrected before you run a KOER (Key On Engine Running) test.
To get rid of the Continuous Memory Codes, deactivate the reader while the codes are being output during the KOEO test.
