I have a 93 ford taurus 3.8L V6 automatic GL. I bought a "ford OBD 1 digital code reader made by Equus off the internet and I am learning how to use it. The model number is 3145. I have performed the “KOEO” test with no problem but when I try the “KOER” test the code reader gives me problems. First I warm the engine up. Next I plug in the code reader and cut it on. Then I press the test/hold button. It then shows a 6 which stands for the “cylinder identification code.” The book says it is suppose to do this but after that instead of testing anything it just shuts off. The code reader cuts itself off. I can’t understand why it is doing this to me. Why is this happening?
It’s my understanding that no code will show unless there’s an on-going fault.
The OP is asking why he can’t start the KOER (Key On Engine Running) self test. Not anything about getting codes out.
Try connecting the code reader, then starting the engine, then pressing the test button. If that doesn’t do it, try holding the test button before starting and then releasing after it is started.
Get the engine up to operating temperature. Shut the engine off and do the KOEO diagnostics. The start the engine and do the KOER diagnostics.
How long are you giving this code reader after the engine ID code? The KOER codes may take a bit longer to progress through as compared to both of the KOEO tests as the engine will run through its paces first.