If you reset your ECU by disconecting the battery, do you lose you ECU flash as well? Im trying to get rid of a CEL.

 

No Flash stays.

 

If you want to get rid of a cel you need to use a code reader to erase it. As far as losing your tune, no matter how many times you disconnect the battery you will never lose the tune.

 

You can get rid of the CEL by disconnecting the battery as well, you just won't know what CEL it is.

 

If I'm not mistaken you'll get rid of the cel light but it will be stored.

 

You both are correct I have reset my CEL by disconnecting the battery but the code was still stored in the computer when I went back to read it...the only real way to clear the code is with a reader

 

thanks for the replys. I think my MAF connector was loose I had previously been messin with the air box, its been running fine now. I reset it. Thanks again. If it returns i'll check the code.

 

I did the same thing last weekend when I went to clean my air filter...all the stupid little things that get you when you're not paying attention

 

There shouldn't be a problem with your flash when you disconnect the battery and the code would be saved on your computer, so if you need to go back to look it is there.

 

why not just go to your local auto parts store and have them check/clear the code for free?

 

the flash stays its permanently written into your ecu

 

Not true. If you disconnect and reconnect the battery too quickly it will stay stored in the ecu. Usually if you disconnect the battery and hit the brake pedal, count for 20 seconds, and then hook the battery back up it's usually cleared completely. I've used this method on mine before, and after doing the above I checked it with a code reader just in case and there was nothing stored or pending.

Only downside to disconnecting the battery is you lose your short term and long term fuel trims, and takes a little bit of driving to get them back.

 

If it is a problem where the code is always getting thrown like the CEL on a cat removal, clearing it once isn't going to keep it from coming back. My CEL just stays on. I check the codes about once a week. You can get you own code puller for about $80.

 

Cool, i always wondered about this!

 

its like shutting your comp off at night when you go to bed as long as everything was saved it will be there in the morning