Intermittent CEL but no codes

[CWhalenSHO]

I've had an intermittent CEL for a while now. Tried the paperclip method to pull codes but never had any luck. Took it to a shop but they weren't gotten any codes. The mechanic did make sure that there was power at engine harness connector where he plugged in his scanner and all was good.

Took it to AutoZone and they couldn't get codes either....

What in the world could be going on?

I thought it might be something with the wiring harness but he was getting power where he plugged the scanner into the engine harness connector. I'm totally at a loss here.

 

[sperold]

If the $100.00 or so doesn't scare you, get your own OBD1 scanner.
I am pretty sure there is a code in there, waiting to be read.

There is a Key off engine off (KOEO) test where you get your stored codes from the "continuous memory" group of codes. You don't even start the car for the group of codes you are after.

After that you can do an "engine timing check" where you confirm that your computer is still capable of controlling the timing (need a timing light to confirm).

Then you wind it up with a Key on Engine Running (KOER) test which checks out all your components and circuits and lets you know what is giving you grief right at this second.

Do your self a favor and get your own.

 

[CWhalenSHO]

OK. Thread revival. I didn't want to start a whole new one.

Used another (differnt) Scanner today and still nothing when doing either the KOEO or the KOER tests.

At this point, I'm stumped as to what to do. Is there anything else out there that could be causing this? This is the 4th time I've tried pulling codes without results.

 

[SeanMc]

Does the CEL come on after the car is warmed up, but then while cruising, it turns off? If so, change your o2 sensors.

 

[CWhalenSHO]

Does the CEL come on after the car is warmed up, but then while cruising, it turns off? If so, change your o2 sensors.

Nope, it comes on within driving the car for maybe 2-3 minutes. If I just cruise, it'll stay on.

If I drive a bunch of short trips (Running errands around town) it has a tendency to stay off for longer. However, it still comes on.

I just don't understand why the CEL comes on and still cannot pull codes after several attempts.

 

[sperold]

When you say "still nothing" while pulling the codes, do you get the 111 code and all the other read outs that go along with it (like 6 for the number of cylinders), or is it Nothing, like no screen outputs.

 

[CWhalenSHO]

No screen outputs.

 

[sperold]

Woahhh, that is not right.
There are two separate connectors, one very big and one very small. The test requires both to be hooked up.
Have a look at the big one, make sure all the pins are straight out.
You are having some kind of connector problem.
Follow the hand book that comes with the scanner.