Lately I've been having issues with my speedo not working sometimes.. but the CEL never came on before. It finally came on yesterday when the speedo wasn't working. So I disconnected the battery, took out the instrument panel, checked the wires and everything in the back. everything looked ok. put it all back together, turned it on, and the CEL was gone. Even though the CEL went away is the code still stored in there?

 

yes, the code will still be stored in the ecu until you clear it out...sounds like you might have a failing engine speed sensor...~100 bucks and a pretty simple installation

 

hmm.. where is the engine speed sensor?

 

I dont have my bentley here.. But on my maxima it was right on top of the tranny and accesible from the engine bay.. That may not be the case for an audi, but it makes sense it would be on the tranny somewhere.

 

its on the transmission but to test it you have to go to the ECU pins, put an LED between pins 3 and 20 now switch ignition on and spin left front wheel the led will flash to confirm its ok

 

hmm.. so it's on the tranny. That's underneath the car towards the back. Is it a bitch to get to?

 

Wait, it's not this thing is it?

 

thats the o2 sensor

 

first class picture though

 

If he disconnected the battery the code was dumped.

kaklexicon, if you are serious about working on your car go buy a Vag-Com from Ross-tech.