hey guys ok. so my car feels like its driving on misfiring cylinders. so i went home got my laptop, plugged into obd port and ran the scan tool. nada, says obd failure. ok so at this point im getting desperate. took it to the mechanic, willing to pay 75 smackers to scan. they link up to my obd port and they get the same thing connection failure. at this point im lost. i need my car for school and with out i got nothing. someone told me to check my fuses, i did they all were fine the only one that i found which might have been a concern was the cigarette lighter had the wrong fuse in it, changed that. i did notice that fuses were missing. anyone have any suggestions or have had a similar problem?

98 audi a4 1.8t

 

Sounds like the OBD port isn't connecting to the ECU. Could be bad connection at the ECU. Make sure you have your radio codes , disconnect the battery, then check the ECU connectors to make sure they are dry and seaterd well.

 

i will deg. check that today. but, if its not that, what else could it be?

 

Bad ECU - Bad Ground

 

Go to most any autoparts stores & ask them to scan it for FREE.

What software are you using, with what cable?

 

i already brought it to a mechanic n had a scan done. they said they could not make a connection. how do i check a ecu ground. where would that be? im going to check my ecu right now to see if any wires came loose. ill report back in a few.

 

The key is in the ingnition in the ON position right when doing this right?

 

connections to the ecu are ok. seems fine to me. im not sure what else to do. any suggestions would be greatly appreciated. oh, 1 more question. if my ecu is bad would that be causing my car to drive on misfiring cylinders? its weird cause it doesnt start to mess around till i drive the car a lot. if i just drive it for like 15 min its ok, but then it really starts to mess around. feels like the car is about to shut off n my rpms drop below 1000. not sure what could cause this, maybe u guys do. thnks for ur help

 

If you have misfires, your CEL would be flashing. What about the key? Do you have it turned on (engine not running) when trying to connect?

 

lol my check flashes like a biotch, then goes solid. it eventually shuts off, and then does he same thing flashes n goes solid. i tried with the key in the ignition with engine on and with engine off. and still nothing.