Check engine light, but no error code

1999 4.0L automatic NP231

My check engine light just came on, but when I tried to read the codes with my Scangauge II, it says there are no codes!

I've been getting a weird vibration/grinding noise when first driving off from being parked, sounds kind of like tire rub, but then it goes away. Could that have anything to do with it?

I have persistent overheating problems, but the CEL came on after running for only a minute or two, and it hasn't overheated in a few weeks.

My oil is 3000 miles old but black.... Could I have a leaking head gasket or something, and could that somehow cause the CEL to go on without any codes?

:smsoap:

I would try disconnecting the battery for 15 minutes or so to see if that resets your check engine light.

The check engine light is not likely to be related to the grinding noise you are hearing.

And a leaking head gasket in and by itself wouldn't cause a CEL

The light went off on its own. Weird...

probably operator error. if the scan tool told me no codes i would have used the tool to turn the light off. if it reappeared get it looked at asap.

change that oil.

VAhasnoWAVES said:

probably operator error. if the scan tool told me no codes i would have used the tool to turn the light off. if it reappeared get it looked at asap.

change that oil.

Click to expand...

Not operator error! :looney:
I've used the SGII before to get codes. A few weeks ago I used it on my coworker's Tacoma and cleared his CEL. All you do is navigate through the menu to the option to read codes, and it spits out the code. It said "no codes", which also means it gives you no option to clear codes.