what does it mean when a code comes up undefined?? so far a few codes poped up on my car. one saying it was a temp sensor (3 long 5 short) and the other was undefined (7 long 9 short). besides going to the dealer and paying a ton of money, anybody ghave any idea on what's causing this?? the light is annoying thanks

 

If you are getting a code that you can't find an answer to, try checking the ECU again, maybe you're reading them wrong.

Also, any chain mechanic (pep boys, STS, jack williams, etc...) will usually scan your car for free. Go there and say you've got a check engine light, and they'll scan it for you and tell you what's wrong.

OR, if you think they're going to BS you, go to autozone and rent an OBD2 scanner, plug it in, and find out what's wrong.

Or, before you go crazy, were you checking your car for codes because you could, or because you got a CEL? If you were just checking for the hell of it, then there is a possiblity that there was a problem before, and the code was never erased from memory.

Also, don't ever go to a dealer. For the love of god, do not go to a dealer. I pulled out the O2 sensor fuse one day, and put it in the wrong spot. Later that day, i got a CEL. I went to the dealer and paid $60 to find out was wrong. I was told that all 4 O2 sensors were not functioning. The service manager said that for all 4 to fail at the same time was unlikely, so they figured it was a wiring harness somewhere that went. They quoted me a figure of like $900 in labor alone, just so they could tear the car apart and find out what it was. I went home p1ssed off, then tried to figure out why all 4 sensors failed at once, so i went back and checked the fuses again. Sure enough, the O2 sensor fuse was not in the right spot. I had the car scanned with another OBD2 scanner, and everything was fine. I will never deal with a dealer again.

 

i took my car to an uncle that has a auto shop (mainly american cars) and he hooked it up to obd2 scanner and it said the same thing "undefined". thanks i guess i have to live with the light on

 

what was the code on it?

 

there you go...gotta read pal

 

take care of the temperature sensor, and when you do, test it for electrical continuity, just to make sure it's not working. If it's actually broken, have the ECU reset, and see if the light comes back. If the sensor is good, then you have other problems, and need it checked out right.